The influence of 17beta-estradiol on annexin 1 expression in the anterior pituitary of the female rat and in a folliculo-stellate cell line

J Endocrinol. 2007 Feb;192(2):429-42. doi: 10.1677/JOE-06-0132.

Abstract

Annexin 1 (ANXA1) is a Ca2+- and phospholipid-binding protein that plays an important role as a mediator of glucocorticoid action in the host-defence and neuroendocrine systems. Sex differences in hypothalamo-pituitary-adrenal (HPA) axis activity are well documented and a number of studies have demonstrated that gonadal steroids act as regulators of HPA activity. The aim of this study was to investigate the effect of ovariectomy and 17beta-estradiol replacement, and estrous cycle stage, on anterior pituitary ANXA1 content. The amount of anterior pituitary ANXA1 determined by western blotting varied with estrous cycle stage with a peak at estrus declining to a trough at proestrus. Ovariectomy resulted in a significant (P<0 x 05) decrease in anterior pituitary ANXA1 content. Administration of 17beta-estradiol (1 microg/100 g) significantly (P<0 x 01) increased anterior pituitary ANXA1 expression in the ovariectomized animals. In contrast, there was no change in pituitary ANXA1 content in response to 17beta-estradiol in adrenalectomized and adrenalectomized/ovariectomized rats. Treatment of TtT/GF cells, a folliculo-stellate cell line, with 17beta-estradiol (1 x 8-180 nM) increased ANXA1 mRNA expression and increased the amount of ANXA1 protein externalized in response to a dexamethasone stimulus. These results indicate that 17beta-estradiol stimulates ANXA1 expression in the anterior pituitary and in vivo an adrenal factor contributes to the mechanism of action.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenalectomy
  • Adrenocorticotropic Hormone / metabolism
  • Animals
  • Annexin A1 / analysis*
  • Annexin A1 / genetics
  • Annexin A1 / metabolism
  • Blotting, Western / methods
  • Cell Line
  • Corticosterone / metabolism
  • Corticotropin-Releasing Hormone / pharmacology
  • Dexamethasone / pharmacology
  • Electrophoresis, Polyacrylamide Gel
  • Estradiol / pharmacology*
  • Estrous Cycle
  • Female
  • Gene Expression / drug effects
  • Glucocorticoids / pharmacology
  • Ovarian Follicle / drug effects
  • Ovarian Follicle / metabolism
  • Ovariectomy
  • Pituitary Gland, Anterior / chemistry
  • Pituitary Gland, Anterior / drug effects
  • Pituitary Gland, Anterior / metabolism*
  • RNA, Messenger / analysis
  • Rats
  • Rats, Sprague-Dawley
  • Reverse Transcriptase Polymerase Chain Reaction
  • Stimulation, Chemical

Substances

  • Annexin A1
  • Glucocorticoids
  • RNA, Messenger
  • Estradiol
  • Dexamethasone
  • Adrenocorticotropic Hormone
  • Corticotropin-Releasing Hormone
  • Corticosterone