Expression And Significance Of Mitochondrial Protein-OPA1 In Serum And Placenta Of Patients With Preeclampsia

Objective:To analyze the expression of mitochondrial protein OPA1 in serum and placental tissue of patients with control、early-onset preeclampsia and late-onset preeclampsia.Between serum and placental tissues,to analyze the consistency of its expression,to research the clinical significance combined with clinical indicators,and to explore the correlation of its occurrence,development and clinical classification.Methods:（1）Subjects:During 2021.04-2022.02 in Second Hospital of Jilin University,we select 27 cases of early-onset preeclampsia,26 cases of late-onset preeclampsia and 30 cases of normal pregnancy group without complications.According to the《Obstetrics and Gynecology（9th Edition）》,preeclampsia detected before 34 weeks was defined as early-onset preeclampsia.Approved by ethics Committee of the Second Hospital of Jilin University.（2）Sample collection:4ml peripheral venous blood of pregnant women was taken within 48h before termination of pregnancy,centrifuged at 4000r/min at 4℃for 15min,and the supernatant was taken into 1.5ml EP tube and stored at-80℃for batch experiments.After cesarean section placenta was delivered,three small placental tissue pieces of 1.0cm~3 in size were taken from the root of umbilical cord to avoid bleeding,calcification and necrosis areas.After washing with normal saline for 5 times,sterile gauze blocks were drained,three parts tissues were respectively placed in 2.5%glutaraldehyde、formalin and liquid nitrogen.The sample in liquid nitrogen were stored overnight transferred to the refrigerator at-80℃.（3）Methods:The morphology of mitochondria in placental trophoblast cells was observed by transmission electron microscopy.The content of OPA1 in serum was measured by ELISA.The expression of OPA1 protein in placental tissues was detected by Western-blot and immunohistochemistry（SP）.SPSS26.0 for data analysis,combined with the clinical data of enrolled patients for correlation analysis.Results:（1）By electron microscope observation,the villi on the surface of trophoblast cells in the control group were arranged neatly,and the morphology of mitochondria in the cells was round or oval,with orderly arrangement,and the structure was clear.In PE group,there were few villi on the surface of trophoblast cells and their arrangement was disordered.Mitochondria swelled and mitochondrial cristae were broken or disappeared in vacuoles.（2）Through ELISA experiment,it was found that in early-onset preeclampsia group,the concentration of OPA1 in serum was significantly lower than that in patients with normal pregnancy and late-onset preeclampsia（p<0.01）.（3）Western blot results showed that in three groups the L-OPA1protein expression in the placental tissues was no difference.Compared to patients with normal pregnancy and late-onset preeclampsia,in early-onset preeclampsia group the expression of S-OPA1 in placental tissue was decreased（p<0.05）.（4）It was found by immunohistochemistry that OPA1 was mainly expressed in the cytoplasm of syncytiotrophoblast cells,with strong positive expression in the control group and low expression in the early-onset preeclampsia.Significantly,the expression of OPA1 protein in the early-onset preeclampsia group was decreased,compared to the control and late-onset preeclampsia groups（p<0.05）.（5）Through the pearson correlation analysis,we found that the expression of OPA1 in serum and S-OPA1 in placenta tissues have a positive correlation（p<0.01）.The expression of OPA1 in serum and S-OPA1 in placenta were negatively correlated with systolic and diastolic blood pressure（p<0.01）.Conclusion:（1）The low expression of OPA1 in serum and S-OPA1 in placenta causes mitochondrial structural damage and dysfunction,which may be involved in the occurrence and development of early-onset preeclampsia.（2）The expression of OPA1 in serum and S-OPA1 in placental tissues is consistent in early-onset preeclampsia,and is correlated with blood pressure of patients.OPA1 in serum may be an indicator of risk assessment in patients with early-onset preeclampsia.（3）The role of mitochondrial protein OPA1 in the occurrence and development of late-onset preeclampsia needs further study.