Placenta-specific Protein 1 Is Involved In Preeclampsia

Background:Preeclampsia,a disorder characterized by hypertension and proteinuria after 20 weeks of gestation and sometimes accompanied by maternal multi-organ dysfunction,affects 3-5%of all pregnancies,and is one of the major causes for maternal and infant mortality and morbidity in the perinatal period.The pathogenesis of preeclampsia is not completely known.Intrauterine hypoxia is a major physiological characteristic of preeclampsia.Inappropriate spiral arterial remodeling is known as the main pathological basis of preeclampsia.The placenta,a transient organ that connects fetus to her mother,is critical in maintaining normal pregnancy and fetal growth,and is involved in the pathogenesis of pregnancy-complicated diseases including preeclampsia.Trophoblast is the main cell type in the placenta.Impaired trophoblast invasion and migration and increased trophoblast apoptosis were noticed in preeclamptic placenta.However,the mechanisms leading to dysfunction of trophoblast remains unknown.Undoubtedly,genes that are abundantly expressed in placenta and regulate trophoblast cells might be involved in the dysfunction of trophoblast and thus participate the pathogenesis of preeclampsia.Placenta-specific protein 1(PLAC1)was abundant in placenta.There were study showed that PLAC1 mRNA concentration is elevated in maternal plasma of preeclamtic women.However,the involvement of PLAC1 in preeclampsia has never been investigated.Our previous finding showed that PLAC1 expressed in trophoblast cells and promoted proliferation,migration and invasion of trophoblast cells.Objectives:To clarify the expression of PLAC1 in placenta of normal pregnancy and women with preeclampsia,and to explore the regulatory effects on thophoblast by PLAC1,and try to clarify its involvement in the pathogenesis of preeclampsia.Methods:Immunohistochemical(IHC)and Western blot were used to test the expression of PLAC1 in the placenta of women with severe preeclampsia and normal pregnancy.Trophoblasts(SWAN-71 and JAR)are cultured at the normoxia and hypoxia condition,and PLAC1 expression was determined by Western blotting.PLAC1 siRNA was used to silence PLAC1.The apoptosis of trophoblast was evaluated by flow cytometry with FITC and PI staining after transfection.Results:Placental PL AC 1 expression was significantly decreased in severe preeclampsia compared with control.The expression of PLAC1 in trophoblasts was also significantly decreased after treated with low oxygen concentration.PLAC1 siRNA significantly increased the apoptosis of thophoblast cells.Conclusions:1.The placental expression of PLAC1 was declined in preeclampsia.2.Expression of PLAC1 significantly reduced in hypoxia concentration compared with normal oxygen.3.Declined expression of PLAC1 increased the apoptosis of trophoblast.4.PLAC1 may play a role in the development of preeclampsia.