The Role And Mechanism Of NSUN5 In The Pathogenesis Of Preeclampsia

Preeclampsia（PE）is a specific hypertensive disorder that occurs during pregnancy and poses a significant threat to the health of both the mother and the fetus.It affects approximately 5%to8%of women worldwide and is a major contributor to maternal and fetal mortality during pregnancy and childbirth.Clinically,mothers with PE experience the onset of high blood pressure（≥140/90mm Hg）and/or proteinuria（≥0.3g/24h）after 20 weeks of pregnancy,along with symptoms of organ dysfunction.Furthermore,both the mother and the fetus may develop long-term cardiovascular complications.Despite ongoing research,the exact cause of PE remains uncertain.Previous studies primarily attributed the placenta as the culprit,but in the intricate process of pregnancy,the interface between the mother and the fetus also plays a vital role in ensuring a successful pregnancy.Increasing evidence suggests that defects in decidualization are an important contributing factor to the development of PE.Based on this,this study explores the impact and mechanism of decidualization on PE by screening clinical samples of pregnant women and conducting multiple experiments.The main research content and conclusions are as follows:（1）In order to study the pathogenesis of PE for early prevention and treatment of this disease that harms human health,we analyzed the results of exon array Bead Chip detection（370 severe PE/482 healthy controls）and Mass ARRAY SNP genotyping（498 severe PE/500 healthy controls）of blood samples from different individuals.The results showed that the single nucleotide polymorphism（SNP）site rs77133388 of NSUN5 was significantly associated with PE.Thereafter,we conducted studies on the impact of the NSUN5 and NSUN5 single nucleotide polymorphism site rs77133388 on PE respectively.（2）In order to investigate the role of NSUN5 in PE,we established a mouse model(Nsun5^-/-)using the CRISPR/Cas9 system.The results showed that Nsun5^-/-mice had reduced body weight compared to the wild-type mice.Additionally,their survival rate gradually decreased to 20%after three weeks of birth.Further examination revealed that Nsun5^-/-mice exhibited multiple organ injuries,with the most severe damage occurring in the kidneys.Furthermore,the glycogen deposition and fibrosis in the kidneys of Nsun5^-/-mice,as well as significantly shortened primary foot processes in the renal glomeruli.Moreover,we found an increase in the expression of the apoptosis signal CASPASE-3 in the kidneys of Nsun5^-/-mice at three weeks old,along with accumulation of DNA damage.Therefore,we deduced that Nsun5^-/-mice may die from severe kidney lesions.（3）In order to further investigate the role of NSUN5 in PE,we explored the role of the NSUN5 SNP rs77133388 in PE.In this study,we used the CRISPR/Cas9 system to generate a C>T single base mutation at the NSUN5 R295C site in exon 7 of NSUN5（NSUN5 R295C）in mice.The study found that pregnant NSUN5 R295C mice showed symptoms of high blood pressure,proteinuria,and other symptoms of PE.Dissection revealed a significant decrease in the weight of the placentas and fetuses of NSUN5 R295C pregnant mice.Histological analysis showed that NSUN5 R295C mice had kidney glomerular swelling at E18.5;electron microscopy showed thickening of the glomerular basement membrane and significantly shortened foot processes.In addition,a significant decrease in the area of the decidua region in the NSUN5 R295C placenta.After inducing decidualization artificially,we found that the NSUN5 R295C mice showed insufficient decidualization and a significant decrease in the number of polyploid cells.This suggests that decidualization is impaired in NSUN5 R295C mice.（4）To further understand the mechanism of decidualization damage in NSUN5 R295C mice,we artificially decidualization and performed transcriptome sequencing on the decidualization tissues.We identified the Il-11rαgene through q PCR and validated the significantly lower levels of Il-11rαin NSUN5 R295C mice compared to the control group through immunohistochemistry and Western blotting experiments.Subsequently,we found significantly reduced levels of phosphorylated JAK2,STAT3,as well as decreased expression of CYCLIN D3 and P21.Additionally,RNA immunoprecipitation experiments revealed binding between NSUN5 and Il-11rα.These experimental results indicate that the NSUN5 point mutation alters maternal decidualization through the IL-11Rα/JAK2/STAT3/CYCLIN D3 pathway,thereby impairing placental development and leading to the occurrence of PE,involved in the onset and advancement of PE.In conclusion,we have investigated the role and molecular mechanism of NSUN5 mutation in PE,providing new insights into the pathogenesis of PE and laying a solid foundation for the prevention and treatment of this disease.