The Role Of MicroRNA-15b In Preeclampsia

ObjectivePreeclampsia（PE）is an adverse exposure that has the greatest impact on the risk of cardiovascular diseases during pregnancy.It has common physiological mechanisms with cardiovascular diseases occurring in the later stage,including endothelial dysfunction,oxidative stress,inflammation and other aspects.Early prevention of cardiovascular diseases should start with early screening and intervention of preeclampsia.Therefore,it should be comprehensively prevented and controlled.Mi R-15b,as a small regulatory RNA,is widely stored in cells in the form of a mediator that interferes with activities,and then plays a related regulatory role at the post-transcriptional level.Recently,many studies have shown that it plays a positive role in regulating cell proliferation,cell invasion,tubulation ability,cell apoptosis process,etc.In recent years,cell experiments have shown that miR-15b can use VEGFR-2mRNA as a target to inhibit trophoblast invasion and endothelial cell tube formation,thus affecting spiral artery remodeling.However,the role of miR-15b in pathogenesis of pathological pregnancy such as PE is rarely studied.In this study,the expression levels of miR-15b and VEGFR-2 in human placental tissue were analyzed to explore the feasibility of factors for PE prevention.To discuss the role of relevant factors in placental trophoblast cells,and to explore the application significance of this pathway in prevention and treatment of PE,so as to provide new research direction and scientific basis for pathogenesis and early clinical prevention and treatment of PE.MethodsFifteen mild PE pregnant women and sixteen severe PE（SPE）pregnant women who gave birth between June 2018 and September 2019 were collected as observation group and Twenty-four normal pregnant women as study control group in obstetrics department of the special medical center of the Chinese people’s armed police force.Reverse transcription polymerase chain reaction（RT-PCR）was used to detect the relative expression levels of miR-15b and VEGFR-2mRNA in placenta.Immunohist-ochemical method was used to detect VEGFR-2 protein’s level in human placenta tissue and observe its specific expression site.And the Western blot technique was used to analyze the VEGFR-2’s level in placenta.The research data are properly described according to the data distribution and application conditions.Statistical processing of quantitative data adopts parametric or nonparametric test methods of grouped data.Qualitative data were analyzed by chi-square or corrected chi-square or even exact probability method according to data conditions.ResultsThe basic clinical data of the study subjects show that the clinical data of normal pregnant women and pregnant women with mild and severe preeclampsia are basically the same in terms of pregnancy age,delivery pregnancy age,heart rate,hemoglobin,platelets and other clinical data,and there is no statistical difference（P﹥0.05）;However,systolic blood pressure,diastolic blood pressure and BMI were not consistent in different study groups(F收缩压=22.74,F舒张压=19.26,F_BMI=12.46,P﹤0.05),p﹤0.05);The admission systolic pressure,diastolic pressure and BMI of pregnant women with mild and severe preeclampsia were higher than those of normal control group(P_{systolic pressure}<0.05;P_{diastolic blood pressure}<0.05;P_BMI﹤0.05);Weight gain during pregnancy showed that the weight gain during pregnancy in severe preeclampsia group was significantly higher than that in control group（p<0.05）.The relative expression of miR-15b showed that miR-15b in mild preeclampsia（PE）group and severe preeclampsia（SPE）group were 1.61±0.41and 2.67±0.53respectively,which were higher than control group（1.00±0.12）(P_{mild preeclampsia VS control group}=0.000;P_{severe preeclampsia VS control group}=0.000).At the same time,with the deepening of PE degree,the expression of miR-15b also increased(P_{severe preeclampsia VS mild preeclampsia}=0.000).However,VEGFR-2mRNA shows the opposite trend to the miR-15b.The expression of VEGFR-2mRNA in PE and SPE is decreased（0.30±0.07 vs1.00±0.14,P=0.000 and 0.29±0.11 vs 1.00±0.14,P=0.000,respectively）.However,there is no difference in PE degree(P _{severe preeclampsia VS mild preeclampsia}=0.727).The expression sites of VEGFR-2 in placental tissues of the three groups are basically the same,mainly located in the nuclei and cytoplasm of villous trophoblast cells and decidual cells.Compared with the control group,the expression intensity of mild and severe preeclampsia groups decreased（11.15±1.68 vs 18.61±2.32,P=0.009;10.83±3.07 vs18.61±2.32,P=0.008）;Compared with the control group,the expression level of VEGFR-2 in mild and severe preeclampsia decreased significantly（0.84±0.30 vs 1.13±0.04,P=0.001;0.92±0.07 vs 1.13±0.04,P=0.008）;There was no significant difference in VEGFR-2 expression between mild preeclampsia and severe preeclampsia（0.84±0.30 vs 0.92±0.07,P=0.134）.ConclusionMi R-15b and VEGFR-2mRNA related pathways may play an important role in the pathogenesis of preeclampsia.Mi R-15b can affect the proliferation and invasion of trophoblast cells in placenta and the remodeling process of uterine spiral artery,which indicates that it may provide early prevention and treatment of preeclampsia and early prevention of cardiovascular diseases with a new research direction.