HUMANIN PEPTIDES AS NOVEL CYTOPROTECTIVE FACTORS IN THE OVARIAN CELLS

MARVALDI CAROLINA; MARTIN DANIEL; GOTTARDO MF; PIDRE M; IMSEN M; ROMANOWSKI V; SEILICOVICH A; JAITA G

Congreso; Reunión Conjunta de Sociedades de Biociencias; 2017

HUMANIN PEPTIDES AS NOVEL CYTOPROTECTIVE FACTORS IN THE OVARIAN CELLSMarvaldi Carolina1, Martin Daniel1, Gottardo María Florencia1, Pidre Matías2, Imsen Mercedes1, Romanowski Victor2, Seilicovich Adriana1, Jaita Gabriela1. 1Instituto de Investigaciones Biomédicas (INBIOMED), UBA-CONICET. 2Instituto de Biotecnología y Biología Molecular (IBBM), UNLP-CONICET. Humanin (HN) peptides have cytoprotective action in several cell types such as neurons, spermatogonias and Leydig cells. Our previous results showed that HN peptides are expressed in normal ovarian cells, being localized in granulose cells, theca cells and oocytes. Also, we observed that HN is expressed in the human granulosa-like tumor cell line (KGN). In addition, we showed that HN increases the viability of KGN cells. The aim of present study was to explore the function of HN peptides in the ovary from adult rats and KGN cells. To evaluate the effect of endogenous HN, we used a baculovirus encoding a shRNA to inhibit HN expression (BV shHN). We injected BV shHN and control baculovirus (BV control) into the ovarian bursa of adult rats. In ovarian sections stained with hematoxylin-eosin, we observed that BV shHN injection reduced the cortex area whereas increased the stroma area. The inhibition of HN expression increased the percentage of atretic follicles (BV control: 15%; BV shRNA: 78%, p < 0.01, 2). In addition, we studied the effect of silencing HN expression on the apoptosis in follicles by TUNEL. BV shRNA increased the percentage of follicles with apoptosis (BV control: 11%; BV shHN: 31%, p < 0.01, 2). Also, to evaluate the function of endogenous HN in KGN cells, they were transduced with BV shHN or BV control. The inhibition of HN expression changed the morphology of KGN cells, which become elongated and fibroblast-like, and increased the percentage of apoptosis of KGN cells (BV control: 0.3%; BV shRNA: 4%, p < 0.01, 2). Considering that the inhibition of endogenous HN modifies the morphology of KGN cells, the architecture of the ovary and increases the percentage of apoptotic KGN cells and follicles with apoptosis, our results suggest that HN peptides exert a cytoprotective action in normal and tumor ovarian cells. HN arises as a novel cytoprotective factor that could play a role in ovarian physiology and pathology.Keywords: ovary, humanin, follicle, KGN, baculovirus