Cholestatic pregnancy is associated with reduced placental 11βHSD2 expression

Intrahepatic Cholestasis of Pregnancy (ICP) is associated with an increased risk of fetal morbidity and mortality and is characterised by elevated bile acids in the maternal and fetal compartments. Bile acids have been shown to attenuate renal 11βHSD2 expression and, given the protective role of placental 11βHSD2 in preventing fetal exposure to excessive maternal cortisol, we aimed to establish whether raised serum bile acids in ICP influence placental 11βHSD2 expression.

Placental tissue from human and murine cholestatic pregnancy was evaluated for changes in 11βHSD2 mRNA expression compared to uncomplicated pregnancy using quantitative PCR. Parallel in vitro studies were performed using BeWo choriocarcinoma cells to assess the effect of different bile acid species on 11βHSD2 gene expression and whether concurrent UDCA administration can reverse any bile acid induced changes.

Placental 11βHSD2 mRNA expression was reduced in human and murine cholestatic pregnancy. In BeWo cells, treatment with the primary bile acid CDCA resulted in reduced 11βHSD2 gene expression, while treatment with other primary bile acids had no significant effect. Furthermore, the tertiary bile acid UDCA, used in the treatment of ICP did not significantly affect 11βHSD2 mRNA levels either alone, or when co-administered with CDCA.

Under cholestatic conditions placental 11βHSD2 mRNA is reduced. Studies in BeWo choriocarcinoma cells demonstrated that CDCA is likely to be the specific bile acid that mediates this effect. UDCA, the main bile acid used to treat cholestasis, did not reduce placental 11βHSD2 expression, further supporting its use in the management of ICP.