The effect of prostaglandin E2 receptor agonists on the aldo-keto reductase (AKR) 1C3 enzyme in eutopic endometrial cells

O Zarroug1, D Fischer1, E Crosbie1, D Woodward2, K Marshall1. 1The University of Manchester, Manchester, UK, 2Dept. of Biological Sciences, Allergan, Irvine, California, USA

Prostaglandin (PG) E2 has been shown to upregulate the release of 17β-oestradiol in ectopic endometrium1. The aim of this study was to investigate the effect of PGE2 agonists, selective for the prostaglandin EP2 and EP4 receptors, on 17β-oestradiol production in eutopic endometrial cells via the aldo-keto reductase (AKR) 1C3 enzyme which catalyses the reduction of oestrone to 17β-oestradiol2.

Human endometrial cells were obtained from consenting female donors (n=4) who were premenopausal and undergoing laparoscopy or hysterectomy. The cells were isolated using a method based on that of Periwal et al., 19953. A mixture of epithelial and stromal cells in 60mm2 petri-dishes were treated with vehicle, the EP2 agonist butaprost4 (1μM) and the EP4 agonist L-902688 5 (1μM) for 48 hours. The conditioned media was collected for 17β-oestradiol measurement by ELISA, whereas the cells were lysed and total RNA was isolated. The RNA samples were reverse transcribed and cDNA was used for the relative quantification of AKR1C3 gene by quantitative real-time PCR. Data were expressed as arithmetic means ± SEM and one-way ANOVA, followed by Dunnett’s C post-hoc test, was used for statistical significance

Fig 1: The relative mRNA expression of AKR1C3 in endometrial cells treated with butaprost and L-902688 for 48 hours (n=4). F(2,9)=4.774,p=0.0386

L-902688 appeared to increase the expression of AKR1C3 by 2.5 fold relative to vehicle and butaprost, but did not have an effect on 17β-oestradiol production. Butaprost did not appear to alter AKR1C3 expression and 17β-oestradiol production. These results show that there is an upregulation of AKR1C3 gene expression mediated by the prostaglandin EP4 receptor without affecting 17β oestradiol production in isolated cells and this is currently being investigated further using ectopic cells.

Fig 2: 17β-oestradiol production by endometrial cells treated with butaprost and L-902688 for 48 hours (n=3)

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2Byrns MC et al. (2010). J Steroid Biochem Mol Biol 118: 177-87

3Periwal SB et al. (1995). In Vitro Cell Dev Biol Anim 31: 744-8

4 Abramovitz M et al. (2000) Biochim Biophys Acta 1483: 285-93

5Billot X et al. (2003) Bioorg Med Chem Lett: 13: 1129-32