RXRα is upregulated in first trimester endometrial glands of spontaneous abortions unlike LXR and PPARγ

Nuclear receptors are necessary for uterine invasion of the trophoblast and therefore important for maintaining a viable pregnancy. The aim of this study was to investigate the expression pattern and frequency of LXR, PPAR gamma and RXR alpha under physiological circumstances and in spontaneous abortions in endometrial glands and decidual tissue cells. A total of 28 (14 physiologic pregnancies/14 spontaneous abortion) human pregnancies in first trimester were analyzed for expression of the nuclear receptors LXR, RXR alpha and PPAR gamma. Expression changes were evaluated by immunohistochemistry in decidual tissue and endometrial glands of the decidua. RXRa expression was up-regulated in the endometrial glands of spontaneous abortion (P<0.015). Similar up regulation of RXRa was found in decidual tissue (P<0.05). LXR and PPAR. expression was unchanged in spontaneous abortion. By Correlation analysis we found a trend to positive correlation of LXR and PPAR. (Spearman correlation coefficient r=0.56, P=0.07) in endometrial glands. In decidual tissue, we found significant negative correlation in the control group, for the combination of RXRa and PPAR. (Spearman correlation coefficient r=0.913, P=0.03). Our data show that RXRa expression is increased in miscarriage in endometrial glands and correlation analysis showed that negative correlation between RXRa and PPAR. disappears in miscarriage. This shift is supposable responsible for the loss of regular function in trophoblast and embryonic tissue.