The downregulation of NSUN5 may contribute to preeclampsia.

Preeclampsia (PE) is a complication of pregnancy characterized by the new onset of hypertension after 20 weeks of gestation. The incidence of PE is steadily rising, posing a significant threat to the lives of both the pregnant woman and the fetus. Most studies on PE pathogenesis currently focus on the placenta, but maternal decidualization forms the foundation for placental growth and development. Recent studies have shown that impaired decidualization is also a cause of PE. Decidualization is a process where endometrial stromal cells gradually transform into secretory decidual cells during early pregnancy. While NSUN5 encodes a member of a conserved family of proteins, its role in pregnancy remains unknown. In this study, we conducted experiments and observed a significant downregulation of NSUN5 expression in severe preeclampsia decidual tissues compared to those of normal pregnant women. When inducing decidualization in vitro, we found an increase in NSUN5 expression. However, when we used siRNA to knockdown NSUN5 expression, the process of decidualization was prevented. Moreover, we observed a decrease in ATP content during both cell decidualization and after knockdown of NSUN5. Finally, through immunoprecipitation combined with mass spectrometry, we discovered that the protein ATP5B interacts with NSUN5. Furthermore, after knocking down ATP5B using siRNA, we observed impaired decidualization. Moreover, transfection with siRNA to suppress NSUN5 resulted in a decrease in ATP5B expression. These significant findings provide strong evidence that NSUN5 plays a crucial role in decidualization and is closely associated with the development of PE through its interaction with ATP5B.