Ovarian modulators of 11beta-hydroxysteroid dehydrogenase (11betaHSD) activity in follicular fluid from gonadotrophin-stimulated assisted conception cycles

Abstract

In the ovary, cortisol-cortisone interconversion is catalysed by isoforms of 11beta-hydroxysteroid dehydrogenase (11betaHSD). The objective of this study was to establish whether human follicular fluid (hFF), obtained after controlled ovarian hyperstimulation, contains paracrine modulators of 11betaHSD activity. Of 274 hFF samples tested for effects in rat kidney homogenates, 206 hFF samples significantly inhibited NADP(+)-dependent oxidation of cortisol within 1 h (by 11-67% of control 11betaHSD activity), whereas 42 hFF samples significantly stimulated 11betaHSD activity (16-210% increase relative to control). Although charcoal-stripping of hFF prevented the inhibition and potentiated the stimulation of NADP(+)-dependent cortisol oxidation in a renal homogenate, effects of individual hFF samples on NADP(+)-dependent cortisol oxidation were independent of intrafollicular progesterone concentrations. Hydrophilic fractions of hFF samples, isolated by C18 column chromatography, stimulated both the NADP(+)-dependent oxidation of cortisol (by 55+/-5%, n=98) and the NADPH-dependent reduction of cortisone (by 86+/-22%, n= 5). In contrast, the hydrophobic fractions of hFF (eluted at 65-85% methanol) inhibited both NADP(+)-dependent 11beta-dehydrogenase and NADPH-dependent 11-ketosteroid reductase activities (by 63+/-2% and 74+/-4%, respectively). None of the C18 column fractions of 50 hFF samples had any significant effect on NAD(+)-dependent 11beta-dehydrogenase activities. The hydrophobic inhibitors of NADP(H)-dependent cortisol-cortisone metabolism did not co-elute with several candidate compounds (prostaglandins E(2) and F(2alpha), cortisol, cortisone, oestradiol, testosterone, progesterone, pregnenolone or cholesterol). Hence, hFF aspirated from women undergoing controlled ovarian hyperstimulation for assisted conception contains both hydrophilic stimuli and hydrophobic inhibitors of glucocorticoid metabolism which appear to be selective for the NADP(H)-dependent, type 1 isoform of 11betaHSD.

Expression of 11beta-hydroxysteroid dehydrogenase (11betaHSD) proteins in luteinizing human granulosa-lutein cells

“…Recently, we have reported data that human follicular fluid samples, from which the hGL cells are isolated, contain both a hydrophilic compound (or compounds) that can acutely increase 11 HSD activities and a hydrophobic compound(s) that can inhibit NADP(H)-dependent 11 HSD activities by up to 62% within 1 h in rat kidney homogenates. The inhibitory compound in human follicular fluid is known to be a lipid that is neither a prostaglandin nor one of several candidate steroids (cortisol, cortisone, oestradiol, testosterone, pregnenolone or progesterone) (Thurston et al 2002). It is possible that the increase in expression of type 1 11 HSD protein observed in this study as human granulosa cells luteinize in vitro may simply be a compensatory rise in enzyme expression due to the increasing inhibition of type 1 11 HSD activities by a paracrine HSD inhibitor.…”

“…As a specific example, progesterone, and its hydroxylated metabolites, can inhibit the activities of both cloned isoforms of 11 HSD in a range of cells and tissues (Lopez-Bernal et al 1980, Souness & Morris 1996, Bujalska et al 1997. In our studies of human follicular fluid, we have excluded progesterone as the major endogenous ovarian inhibitor of type 1 11 HSD activities based on: (1) its relative potencies for type 2 versus type 1 11 HSD; (2) the lack of correlation between degree of enzyme inhibition and progesterone concentrations in individual follicular fluid samples; and (3) the fact that the major inhibitor of type 1 11 HSD elutes from a C18 cartridge at higher methanol concentrations than does progesterone (Thurston et al 2002). To establish whether the decline in 11 HSD activities and/or the increase in the expression of type 1 11 HSD protein in luteinizing hGL cells could simply reflect increasing progesterone production, experiments were repeated in the presence of AG: an inhibitor of cytochrome P450 cholesterol side-chain cleavage.…”

The in vitro metabolism of cortisol by ovarian follicles of rainbow trout (Oncorhynchus mykiss): comparison with ovulated oocytes and pre-hatch embryos

“…The maintenance of a stable high concentration of cortisol suggests that the glucocorticoid plays an important role in the 'normal' development and maturation of the oocyte. This hypothesis is supported by evidence of a significant reduction in the meiotic competency of the oocyte when antral fluid cortisol concentrations are elevated (Yang et al 1999, Thurston et al 2002, Andersen 2003.…”

“…The maintenance of a stable high concentration of cortisol suggests that the glucocorticoid plays an important role in the 'normal' development and maturation of the oocyte. This hypothesis is supported by evidence of a significant reduction in the meiotic competency of the oocyte when antral fluid cortisol concentrations are elevated (Yang et al 1999, Thurston et al 2002, Andersen 2003.Far less is known about the role of cortisol on oocyte development and maturation in oviparous fishes, although there is evidence of the involvement of cortisol in several aspects of ovarian function (reviewed by Leatherland et al (2010)). The ovarian follicles of q 2012 Society for Reproduction and Fertility…”

Cortisol Inhibition of 17b-Estradiol Secretion by Rainbow Trout Ovarian Follicles Involves Modulation of Star and P450scc Gene Expression

“…In mammals, high levels of free glucocorticoids are present in the ovarian follicle antral fluid and glucocorticoid receptors (GRs) are present in ovarian tissues [5][6][7][8][9][10][11][12], suggesting an essential role for the glucocorticoid in oocyte development and maturation, possibly by modulating the meiotic competence of the oocyte [7]. Elevated ovarian glucocorticoids were found to have adverse affects on the maturation of oocytes and increased anovulation [13][14][15][16][17], but it is not clear whether these responses can be attributed to a direct action of the glucocorticoids on ovarian steroidogenesis.…”