Objective  To study the changes in the expression of nicotinamide adenine dinucleotide phosphate (NADPH), a glucose metabolism-derived antioxidant, in late-onset preeclampsia (LOPE) placenta tissue and the correlation with oxidative stress.

  Methods  A total of 13 normal pregnant women and 13 pregnant women with LOPE who were hospitalized in the Obstetrics Department, the First Affiliated Hospital of Chongqing Medical University and who underwent elective cesarean section between November 2020 and October 2021 were included in the study. Placenta tissues were collected from the subjects. Dichloro-dihydro-fluorescein diacetate (DCFH-DA) assay was done to determine the ROS levels in the placenta tissues of the LOPE group and the normal control group. Spectrophotometric analysis was conducted to determine the levels of NADPH, glutathione (GSH), and glucose, and the expressions and activities of glucose-6-phosphate dehydrogenase (G6PD) and phospho-gluconate dehydrogenase (PGD), key rate-limiting enzymes of the pentose phosphate pathway (PPP), in the placenta tissues of the LOPE group and the normal control group. Western blot was done to determine changes in the protein expressions of phosphofructokinase 1 (PFK1), a key rate-limiting enzyme of the glycolytic pathway, G6PD, and PGD in the placenta tissues from the two groups.

  Results  ROS levels in the placenta tissue of the LOPE group were significantly higher than those of the control group (P<0.05). The levels of NADPH and GSH, two antioxidants, and glucose in the LOPE placenta were significantly higher than those of the control group (P<0.05). The expression of PFK1 was significantly elevated in the LOPE group (P<0.05). However, there were no significant differences in the activities and protein expression of G6PD and PGD between the two groups.

  Conclusion  Glucose metabolism reprogramming takes place in LOPE placenta tissue, which may be one of the causes of the abnormal elevation of NADPH and GSH.