Estradiol regulates the expression of c-FLIP in anterior pituitary cells

G. JAITA; S. ZARATE; J. FERRARIS; G. EIJO; M. L. MAGRI; F.GOTTARDO; D. PISERA; A. SEILICOVICH

Florencia

Congreso; 15º International Congress of Endocrinology; 2012

Our previous results demonstrate that estrogens increase the expression of death receptors TNFRI and Fas in the anterior pituitary and sensitize anterior pituitary cells to pro-apoptotic factors. c-FLIP is a protein that interacts with procaspases 8 and 10 modulating death receptor activity. In normal tissues, two isoforms of c-FLIP have been identified, the short isoform (c-FLIPs) and the long one (c-FLIPL). c-FLIPs has an anti-apoptotic action whereas c-FLIPL has either anti-apoptotic, pro-apoptotic or proliferative actions depending on the tissue and its level of expression. To investigate whether c-FLIP is involved in the apoptosis of anterior pituitary cells, we evaluated the action of estradiol on c-FLIP expression in anterior pituitary cells from ovariectomized (OVX) Wistar rats and in the somatolactotrope cell line GH3. Both c-FLIPL and c-FLIPs, identified by Western blot, were detected in the anterior pituitary gland and GH3 cells. In cultured anterior pituitary cell from OVX rats, 17b-estradiol (E2, 10-9M) increased the expression of c-FLIPL (control: 1.50±0.42, E2: 1.91±0.59, P