The Expression Of ERAP-1 In Placenta Of Preeclampsia And The Effect Of Hypoxia On The Expression Of ERAP-1 In Trophoblast Cells

Background:Preeclampsia?PE?is a common idiopathic disease during pregnancy and is one of the main causes of maternal and perinatal mortality,which seriously endangers the health of mothers and infants.However,the specific mechanisms remains obscure.At present,abnormal invasion of trophoblasts,inflammatory immune imbalance,angiogenesis disorders,vascular endothelial cell damage and other mechanisms are considered to play an important role in preeclampsia.ERAP-1 belongs to the"oxytocin subfamily"in the zinc finger metal matrix peptidase M1 family.It can participate in antigen presentation of MHC-I molecules and play a role in immune regulation.ERAP-1 can decompose angiotensin II and participate in blood pressure regulation.In addition,ERAP-1 can inhibit angiogenesis by inhibiting vascular endothelial growth factor.Foreign studies have demonstrated that the expression of ERAP-1 in decidua of preeclampsia pregnant women in the third trimester of pregnancy is significantly higher than that of pregnant women with normal blood pressure.The correlation between ERAP-1 and preeclampsia has not been reported in the domestic literature.In view of the important role of immune factors and vascular factors in the pathogenesis of preeclampsia,it is reasonably speculated that ERAP-1 may be involved in the occurrence of preeclampsia.Therefore,exploring the relationship between ERAP-1and preeclampsia will help to further understand its pathogenesis.Objective:To explore the expression of ERAP-1 in placenta tissues of preeclampsia patients and normal pregnant women,and to explore the expression of ERAP-1 in trophoblasts in hypoxic environment,to probe the role of ERAP-1 in the pathogenesis of preeclampsia.Methods:?1?Study on placental tissue in patients with preeclampsia:Twenty-four patients with preeclampsia who received caesarean section from September 2016 to September 2018 were recruited as observation group;Twenty-four normal pregnant woman were selected as normal control during the same period group.Then,real-time PCR was performed to detect the expression of ERAP-1 mRNA in placental tissue;Western blot and immunohistochemistry were performed to analyze the expression and location of ERAP-1 protein in placental tissue.?2?Study on the cell model:Human trophoblastic cell line HTR-8/SVneo were divided into two group:low oxygen?2%O₂?concentration group and normal oxygen concentration group;Then,the cells were harvest for Real-time PCR at 6h,12h,24h and western blot test at 24h,48h,72h.Results:Study on placental tissue in patients with preeclampsia:?1?There were no significant differences in age,BMI,and number of pregnancies?P>0.05?between preeclampsia and control group.There were significant differences in the number of days of pregnancy,systolic blood pressure,diastolic blood pressure and neonatal weight?P<0.01?between preeclampsia and control group.?2?Real-time quantitative PCR showed that the expression of ERAP-1 mRNA in placenta tissue of preeclampsia group was higher than that of the control group?P<0.05?.?3?Western blot showed that the expression of ERAP-1 protein in placenta tissue of preeclampsia group was higher than that of the control group?P<0.05?.?4?Immunohistochemistry indicated that the ERAP-1 protein in the placenta tissue was mainly expressed in cytotrophoblast cells and syncytiotrophoblast cells,and stained in cell interstitial,cell membrane and cytoplasm,and the protein level was higher than that of the control group.The difference was statistically significant?P<0.05?.Study On the cell model:?1?The trophoblast cells were cultured for 6 hours under hypoxic conditions,and the expression of ERAP-1 mRNA was decreased compared with the control group;However,after cultured for 24 hours,the expression of ERAP-1 mRNA in hypoxic group was higher than the control group and the difference was statistically significant?P<0.05?.?2?After 24 and 48 hours of hypoxia culture,the expression of ERAP-1 protein between hypoxic and normal group was not different?P>0.05?.After 72 hours of hypoxia culture,the expression of ERAP-1 protein was higher than that in the control group?P<0.05?.Conclusions:The expression of ERAP-1 mRNA and protein in placenta of patients with preeclampsia is elevated.Hypoxia can induce the expression of ERAP-1mRNA and protein in trophoblast cells,suggesting that ERPA-1 may be involved in the pathogenesis of preeclampsia.