Contribution of placental 11β-HSD2 to the pathogenesis of preeclampsia

Preeclampsia, a major human pregnancy-specific disorder, leads to maternal and fetal morbidity and mortality. Here we reported that 11 beta-hydroxysteroid dehydrogenase type 2 (11 beta-HSD2), an enzyme that degrades active glucocorticoids, is one of the key factors that contributes to preeclampsia development. In the pregnant rat model, we firstly confirmed that administration of 11 beta-HSD2 inhibitor carbenoxolone (CBX) subcutaneously or by placenta-targeted delivery system could lead to a decrease in placental 11 beta-HSD2 expression and activity and an increase in corticosterone level in placenta and maternal circulation. Then, we showed that subcutaneous administration and placenta-targeted delivery of CBX resulted in the hallmark of preeclampsia-like features including hypertension, proteinuria, renal damages as well as elevated circulatory soluble fms-like tyrosine kinase 1 (sFlt1) and increased sFlt1/placental growth factor (PlGF) ratio in pregnant rats. These animals displayed decreased trophoblast invasion in uterus, impaired spiral artery remodeling, and reduced placental blood flow. Preeclampsia-like features could also be induced by administration of dexamethasone in pregnant rats. In the cultured human trophoblast models, we found that cortisol only inhibited migration and invasion of the extravillous trophoblasts with 11 beta-HSD2 knockdown, and promoted sFlt1 release in the cultured syncytiotrophoblasts with 11 beta-HSD2 knockdown. Furthermore, we elucidated that cortisol stimulated a disintegrin and metalloprotease (ADAM)17 expression in placentas, thereby promoting sFlt1 release in placenta. Collectively, our study provided the evidence that placental 11 beta-HSD2 dysfunction plays a key role in the development of preeclampsia and immediately identified innovative target to counteract preeclampsia.