Involvement Of Circular RNAs In Preeclampsia And Mechanistic Study

Background and objectives:Preeclampsia refers to the occurrence of hypertension and proteinuria after 20 weeks of pregnancy as the main characteristics,which can involve the brain,eyes,liver,kidney and other organs.Preeclampsia is a specific disease during pregnancy.Preeclampsia is a complication of pregnancy and one of the leading causes of maternal and perinatal mortality.At present,the pathogenesis of preeclampsia has not been completely clear.Lots of patients show clinical symptoms and signs disappear after delivery of placenta,therefore,the relationship between pathological changes of placenta and preeclampsia was inferred.At present,there is a lack of specific clinical indicators for early screening and disease severity prediction for preeclampsia.The circular RNAs is a kind of non-coding RNA molecule which does not have5' end cap and 3' end poly?A?tail and forms ring structure by covalent bond.They are not easily degraded by exonuclease RNaseR nucleic acid,so they are more stable than linear RNA.Circular RNAs has many biological functions and plays an important role in the development of diseases.Recent studies have found that the complex competitive endogenous RNA network of circular RNAs and micro RNAs play an important role in the pathogenesis of preeclampsia.However,there are few studies on the correlation between circular RNAs and preeclampsia.This subject will identificate the expression of circular RNAs in placenta of preeclampsia patients.Afer that the function of circRNAs will be analysised.We selected hsa_circ₀015383 as a target molecule for follow-up study,the value of hsa_circ₀015383 as potential biomarker of preeclampsia will be estimated.We hope to provide new research ideas for early diagnosis and treatment of preeclampsia.Methods:1.According to the strict inclusion and exclusion criteria,5 cases of preeclampsia and 5 cases of normal pregnancy matched by age,gestational week,pregnancy history,pre-pregnancy BMI were selected.The circRNAs expression profiles in placental samples had been identificated by high-throughput sequencing.Then differentially expressed genes had been screening by DeSeq2.A variety of bioinformatics techniques had been used to analyze the differentially expressed circRNAs.2.The differences between hsa_circ₀015383,Wnt5 a and ?-catenin protein expression levels had been examined in 30 preeclampsia and 30 normal pregnancy placentas.A SiRNA transfected HTR-8/SVNEO cell models had been constructed.We examined the effect of hsa_circ₀015383 on cell function by MTT cell proliferation experiments,Transwell cell migration and invasion experiments,and angiogenesis experiments.3.Hsa_circ₀015383 levels had been measured in 31 preeclampsia and 78 normal pregnant women at 20 weeks of gestation by RT-PCR serum.The ROC curve had been drawn and the area under curve had been calculated.We evaluated the value of hsa_circ₀015383 for early diagnosis of preeclampsia.Results:1.A total of 5038 circRNAs expression abundances had been detected in 10 placental samples.Using P<0.05,Fold Change ?1.5 times as the differential gene screening criteria,277 differentially expressed circRNA molecules had been obtained,including 130 high expression and 147 low expression.The GO and KEGG pathway enrichment analysis of the source genes of the differential circRNAs suggested there were obvious enrichment phenomena in endoplasmic reticulum protein processing,phospholipid metabolism and RAS signaling pathway.2.Hsa_circ₀015383 expression level were upregulated in placental tissues of preeclampsia patients?P<0.05?.This result was consistent with the sequencing results.The expression level of Wnt5 a and ?-catenin proteins in HTR-8/SVNEO cell lines increased significantly after down-regulation of the hsa_circ₀015383?P<0.05?,while the cell proliferation capacity did not change significantly?P>0.05?.3.The serum expression level of hsa_circ₀015383 in pregnant women with preeclampsia at 20 weeks of pregnancy was significantly higher than that in normal pregnant women?P<0.05?,and the area under the curve was 0.813.Sensitivity was0.742 and specificity was 0.756.Conclusion:1.There were abnormal expression of circRNAs in placental tissue of preeclampsia compared with normal placental tissue,which involved in the development of preeclampsia through certain pathways.2.Hsa_circ₀015383 were highly expressed in placental tissues of preeclampsia patients,and their expression levels were negatively correlated with Wnt5 a and ?-catenin protein expression levels.Hsa_circ₀015383 may negatively regulate the Wnt signaling pathway by binding to hsa-miR-197,which in turn affects EVTs migration,invasion and tube forming ability,and ultimately participates in preeclampsia pathogenesis.3.Hsa_circ₀015383 had certain value for early diagnosis of preeclampsia,and it was expected to be a new biomarker for preeclampsia in the future.