congresos y reuniones científicas
Expression and function of humanin peptides in ovarian cells
MARTÍN, DANIEL; MARVALDI, CAROLINA; IMSEN, MERCEDES; SEILICOVICH, ADRIANA; JAITA, GABRIELA
Congreso; Jornadas Anuales Multidisciplinarias Sociedad Argentina de Biología; 2016
Sociedad Argentina de Biologia
Humanin (HN) and Rattin (HNr, rat homologous peptide) have cytoprotective action in several cell types such as neurons, spermatogonias and Leydig cells. However, little is known about the expression and action of these peptides in the ovary. We aimed to explore the expression and function of HN peptides in the ovary from prepuberal rats, cycling adult rats and in a human granulosa-like tumor cell line (KGN). We investigated the expression of HNr in ovarian sections from untreated prepuberal rats (rich in preantral follicles), or treated with DES (rich in early antral follicles) or PMSG (rich in preovulatory follicles). Immunohistochemical (IHC) staining showed HNr expression in granulose and theca cells, and also in oocytes. The HNr expression pattern was similar among follicles of the same type in untreated or treated prepuberal rats. In PMSG-treated rats, HNr was mainly expressed in theca cells. In ovarian sections from cycling rats the pattern of HNr expression was similar to that of treated prepuberal rats and HNr was also expressed in luteal cells. In addition, KGN cells expressed HN. To study the role of HNr, we performed the TUNEL assay together with IHC for HNr in ovarian sections. HNr+ cells were TUNEL-negative in PMSG-treated rats. We analyzed the effect of HN on viability of KGN cells by MTT assay. HN increased the viability of KGN cells (C: 0.24 ± 0.02, HN 0.25 µM: 0.40 ± 0.02, HN 0.5 µM: 0.36 ± 0.02, HN 1µM: 0.41 ± 0.01, p < 0.01 vs control). Our results show that HNr is present in all follicular cells, including oocytes, and also show strong intensity in luteal cells. Considering that HNr is absent in apoptotic ovarian cells and that HN increases the viability of KGN cells, our results suggest that HNr/HN may play a cytoprotective role in ovarian cells.