Apoptosis

, Volume 12, Issue 4, pp 769–779

Regulation of the expression of prostate apoptosis response protein 4 (Par-4) in rat granulosa cells

  • Inmaculada Hernandez Gonzalez
  • Pino Santana
  • Ignacio Gonzalez-Robayna
  • Milagros Ferrer
  • Victoria Morales
  • Felix Lopez Blanco
  • Luisa F. Fanjul
Article

DOI: 10.1007/s10495-006-0019-7

Cite this article as:
Gonzalez, I.H., Santana, P., Gonzalez-Robayna, I. et al. Apoptosis (2007) 12: 769. doi:10.1007/s10495-006-0019-7

Abstract

The par-4 gene, directs the expression of a protein in the rat ventral prostate after apoptotic stimuli but not growth stimulatory, growth arresting or necrotic signals. Since Par-4 expression appears to be ubiquitous we investigated the possibility of Par-4 having a role in the rat ovary granulosa cells apoptotic death. Par-4 mRNA was detected by RT-PCR with oligonucleotides designed to prime Par-4 leucine zipper in the ovaries of 12 day old rats and reached the higher levels in 24 days old rats. In situ hybridization analysis revealed that Par-4 expression is restricted to granulosa cells. PMSG priming of 24 day old rats for 2 days greatly reduced Par-4 expression in granulosa cells as determined by in situ hybridization, RT-PCR of mRNA and protein immunodetection with Western blot. Granulosa cells placed in serum-fee culture, exhibited increased levels of Par-4 mRNA and protein, in good correlation with the degree of apoptosis. The culture-induced increases in Par-4 are significantly prevented by FSH. Transient transfection of granulosa cells with Par-4 leucine zipper domain that functions as a dominant-negative regulator of Par-4 activity resulted in lower rates of apoptosis while overexpression of the full length Par-4 counteracted FSH effects on apoptosis. Par-4 association with PKCζ which is supposed to inhibit this kinase mediated antiapoptotic way is also prevented by FSH and, FSH antiapoptotic effects are counteracted by a PKCζ specific inhibitor. These findings indicate that FSH by suppressing Par-4 expression in the ovary activates PKCζ-dependent antiapoptotic pathway and suggest that Par-4 is part of the mechanism underlying granulosa cells apoptotic demise.

Keywords

Par-4GranulosaFollicular atresia

Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  • Inmaculada Hernandez Gonzalez
    • 1
  • Pino Santana
    • 1
  • Ignacio Gonzalez-Robayna
    • 1
  • Milagros Ferrer
    • 1
  • Victoria Morales
    • 1
  • Felix Lopez Blanco
    • 1
    • 2
  • Luisa F. Fanjul
    • 1
  1. 1.Departamento de BioquímicaBiología Molecular y Fisiología, Universidad de Las Palmas de Gran CanariaLas Palmas de Gran CanariaSpain
  2. 2.Departamento de Ciencias ClínicasFacultad de Medicina, Universidad de Las Palmas de Gran CanariaLas Palmas de Gran CanariaSpain