Increased expression of N-myc downstream-regulated gene 1 (NDRG1) in placentas from pregnancies complicated by intrauterine growth restriction or preeclampsia

Abstract

N-myc downstream-regulated gene 1 (NDRG1) modulates placental response to hypoxia. We therefore hypothesized that the expression of NDRG1 is altered in placentas from pregnancies complicated by intrauterine growth restriction (IUGR) or preeclampsia (PE), which are associated with fetoplacental underperfusion and cellular hypoxia. Thirty-five pregnant women in the third trimester of pregnancy were recruited according to the following 3 groups: (1) normal term pregnancy (n = 10), (2) pregnancy complicated by IUGR (n = 9), and (3) pregnancy with severe PE (n = 16). Placental samples were collected after cesarean delivery without labor. NDRG1 was measured with the use of immunostaining, Western blot, and real-time quantitative polymerase chain reaction (RT-qPCR). Umbilical artery blood flow velocity waveforms were recorded by Doppler ultrasound in women with IUGR and PE. By using immunostaining, we found a predominant expression of NDRG1 in the cytoplasm of villous trophoblasts. The expression of NDRG1 in samples from PE or IUGR was higher than control, with highest expression in PE. We confirmed these results by using immunoblotting and RT-qPCR. There was no correlation between the level of NDRG1 and umbilical artery blood flow. The expression of NDRG1 is upregulated in placentas from pregnancies complicated by severe PE or IUGR. This finding likely reflects trophoblast response to hypoxic injury.