Expression of osteoprotegerin in placenta and its association with preeclampsia.

Pei Shen,Shanshan Ni,Jin Jia,Yunhui Gong,Lin Zhang,Tao Wang,Bin Zhou,Yueyue Chen,Rong Zhou,Yapin Song

doi:10.1371/journal.pone.0044340

Pei Shen, Shanshan Ni + Show 8 more

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https://doi.org/10.1371/journal.pone.0044340

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Abstract

BackgroundOsteoprotegerin (OPG), a key regulatory factor in bone metabolism, was documented also a potential pro-angiogenic factor, which acts an important role in protecting vascular endothelial cells. Since preeclampsia has gradually been employed to be vascular diseases, we speculated that OPG might be associated with preeclampsia. The study was to evaluate the level of OPG protein and mRNA in placenta, and investigate the relationship between OPG and the pathogenesis of preeclampsia.Methodology/Principal FindingsPlacental specimens from 30 term normal pregnancy, 30 severe preeclampsia and 30 mild cases were studied. The expression and levels of OPGs’ protein and mRNA were detected by immunohistochemisty, western blot analysis and real-time quantitative PCR analysis respectively. The expression of OPG protein was found in cytoplasm of placenta cytotrophoblasts and syncytiotrophoblasts in three groups. There were no significant differences of OPG protein between the maternal and fetal side in each group. The OPG protein and mRNA levels in severe preeclampsia were significantly higher than those in mild cases and normal pregnancy. However, there were no markedly differences of the OPG protein and mRNA levels between term delivery and preterm delivery in severe cases. In preeclampsia, the OPG protein and mRNA level was positively correlated with systolic blood pressure and 24 h urinary protein respectively.Conclusions/SignificanceOPG protein and mRNA level in placentas of preeclampsia were found abnormal compared with normal pregnancy. In preeclampsia, the OPG protein and mRNA levels were closely related with its important clinical parameters. Taken together, OPG might be closely correlated with the pathogenesis of preeclampsia.

Highlights

Preeclampsia is a specific disorder known to promote maternal or perinatal mortality and morbidity during pregnancy [1]
Expressions of OPG protein in severe preeclamptic group (SPE), mild preeclamptic (MPE) and normal control (CTRL) group were shown in figure 2 (Fig2) by Western blotting
No significant difference of OPG protein level was found by western blot between the maternal side and fetal side of the placenta in each group (P.0.05).On both the maternal side and the fetal side of placenta, strong expression of OPG protein was observed in severe preeclampsia group (SPE)

Summary

Introduction

Preeclampsia is a specific disorder known to promote maternal or perinatal mortality and morbidity during pregnancy [1]. A large of evidences suggested that preeclampsia could be associated with many factors, such as endothelial dysfunction, inflammation, insulin resistance [2,3,4], its etiology and pathogenesis has not been extensively investigated. Nowadays researches indicated the endothelial dysfunction may potentially function as a inducer role in the pathogenesis of preeclampsia [5,6,7]. Many studies documented that OPG was a potential pro-angiogenic factor, which acts as an important regulatory factor in protecting vascular endothelial cells [10,11,12]. Osteoprotegerin (OPG), a key regulatory factor in bone metabolism, was documented a potential proangiogenic factor, which acts an important role in protecting vascular endothelial cells. The study was to evaluate the level of OPG protein and mRNA in placenta, and investigate the relationship between OPG and the pathogenesis of preeclampsia

Methods

Results

Conclusion