Corticosteroid metabolism in human granulosa‐lutein cells

Abstract

The dehydrogenase and oxoreductase reactions catalysed by 11 beta HSD both occur in granulosa-lutein cells at the time of follicular rupture, probably due to 11 beta HSD1. A lack of measurable conversion of dexamethasone to 11-dehydrodexamethasone suggests that dehydrogenation due to 11 beta HSD2 is low or absent. Neither type nor level of 11 beta HSD activity measured under the present assay conditions correlates with IVF outcome.

Regulation of 11beta-hydroxysteroid dehydrogenase type 1 gene expression by LH and interleukin-1beta in cultured rat granulosa cells

“…11 HSD type 1 (11 HSD1) is principally an 11-oxoreductase (converts cortisone to cortisol, and 11-dehydrocorticosterone to corticosterone), whereas 11 HSD type 2 (11 HSD2) is a strong 11-dehydrogenase (back-converts cortisol to cortisone, and corticosterone to 11-dehydrocorticosterone). We have previously shown that a switch occurs in 11 HSD gene expression during granulosa cell luteinisation, the pattern of which suggests an intraovarian role for anti-inflammatory glucocorticoids in limiting the inflammatory component of ovulation (Tetsuka et al 1997, 1999, Thomas et al 1998. Granulosa cells in developing follicles express mainly 11 HSD2 mRNA, but little or no 11 HSD1 mRNA.…”

“…After exposure of preovulatory follicles to an ovulation-inducing dose of LH or hCG, 11 HSD2 mRNA expression is suppressed, whereas 11 HSD1 mRNA is enhanced. This shift in potential for glucocorticoid inactivation (oxidation by 11 HSD2) to activation (reduction by 11 HSD1) is reflected in the predominantly reductive (cortisone to cortisol) mode of glucocorticoid metabolism undertaken by luteinising granulosa cells in vitro , Thomas et al 1998. Differential regulation of 11 HSD gene expression before follicular rupture may therefore be the means by which the intrafollicular concentration of cortisol is increased before ovulation .…”

Glucocorticoid metabolism in the bovine cumulus–oocyte complex matured in vitro

“…The expression of HSD11B1 is dramatically increased, while that of HSD11B2 decreased after the preovulatory gonadotropin surge or LH/hCG treatment in human (Tetsuka et al 1997), macaque (Fru et al 2006) and rat (Tetsuka et al 1999b) follicles/ovaries as well as cultured granulosa cells of rats (Tetsuka et al 1999a) and macaques (Fru et al 2006). Likewise, both dehydrogenase and reductase activities brought about by HSD11B1, but not by HSD11B2, have been demonstrated in cultured human granulosa-lutein cells collected shortly before ovulation (Thomas et al 1998). These results indicate that the activation of HSD11B1 is responsible for a temporal increase in the ratio of cortisol to cortisone and the level of free cortisol in human follicular fluid (Harlow et al 1997, Andersen 2002).…”

“…The residue was dissolved with 10 ml of ethyl acetate containing 1 mM each of cold cortisol and cortisone, or dexamethasone (Sigma-Aldrich) and 11-dehydrodexamethasone (Steraloids, Inc., Newport, RI, USA) and spotted on a Chromato Sheet (Wako) for thin layer chromatography (TLC). Steroids were separated using the solvent system chloroform-ethanol, 92:8 (v/v) (Thomas et al 1998). After TLC, the resolved steroids were localized under UV (254 nm) and each area was cut out for determination of specific radioactivity.…”

“…Reductive and oxidative activities of HSD11B1 and HSD11B2 in COCs were measured by the radiometric conversion assay reported previously (Thomas et al 1998). COCs were cultured as mentioned above with 100 nmol/l of radiolabeled cortisol ([1,2,6,7-3 H(N)] hydrocortisone 73.4 Ci/mmol; PerkinElmer Japan, Hodogaya, Kanagawa, Japan) or cortisone ([1,2-3 H]cortisone 60 Ci/mmol; American Radiolabeled Chemicals, Inc., Tokyo, Japan).…”