Reduced expression of survivin, the inhibitor of apoptosis protein correlates with severity of preeclampsia

IntroductionPreeclampsia is a major complication of pregnancy affecting maternal and fetal health. Although the pathogenesis of preeclampsia is unclear, it is believed that trophoblast apoptosis plays an important role in the pathogenesis of preeclampsia during pregnancy. Survivin is a member of the inhibitor of apoptosis protein family that uniquely promotes trophoblast proliferation. In this study we investigated the alteration of survivin levels during pregnancy and compared the survivin protein and mRNA between preeclampsia and normal pregnancy.MethodsThe mRNA level of survivin in first, second and third trimester placentae was measured by Real-time PCR. The expression of survivin in preeclamptic placentae (including severe and mild preeclampsia) and in age-matched normal placentae was measured by immunohistochemistry. The mRNA levels of survivin in preeclamptic or normal placentae were measured by Real-time PCR.ResultsThe mRNA level of survivin was significantly reduced throughout gestation. The mRNA level of survivin in preeclamptic placentae was significantly reduced compared to that in normal placenta. The mRNA level of survivin in severe preeclamptic placentae was further significantly reduced compared to that in mild preeclamptic placentae. In addition, survivin was expressed on syncytiotrophoblasts and cytotrophoblasts and the expression of survivin was significantly decreased in preeclamptic placenta compared to that in normal placenta (p = 0.01). Furthermore the expression of survivin in severe preeclamptic placentae was significantly lower than that in mild preeclamptic placentae.ConclusionOur current data suggests lower placental expression of survivin may be associated with the severity of preeclampsia.