The expression of imprinted genes IGF2 and PHLDA2 in mid-pregnancy have predictive values for the development of pre-eclampsia

Objective: Insulin-like growth factor-2 (IGF-2) and pleckstrin homology-like domain, family A, member 2 (PHLDA2) appear to play an important role in paracrine interactions at the maternal-fetal interface in human pregnancy. But the potential predictive value of serum IGF-2 and PHLDA2 concentrations in pre-eclampsia remains to be established. The goal of the present study was to explore the expression of IGF2 and PHLDA2 in mid-pregnancy with pre-eclampsia (PE). Methods: Samples of serum were collected from women with normal mid-pregnancy women (control group, n=21), mild pre-eclampsia (M-PE group, n=19) and severe pre-eclampsia women (S-PE, n=19). The expressions of IGF2 and PHLDA2 in the serum were determined by ELISA and western blot. After delivery, the fresh placental tissues were collected. The expression levels of IGF2 and PHLDA2 in placenta were detected by real-time PCR, western blot and immunohistochemistry. Results: It was found that the concentrations of IGF2 and PHLDA2 were remarkably dropped in comparison with control group. And there was significant difference in PHLDA2 expression between mild pre-eclampsia and severe pre-eclampsia in serum. After delivery, the differences in imprinted genes IGF2 and PHLDA2 were found in placental tissues between PE and normal pregnancy. mRNA and protein expression levels were all obviously decreased in PE groups. Conclusion: These data are the first to demonstrate imprinted genes IGF2 and PHLDA2 associated with PE in mid-pregnancy. It illustrates that IGF2 and PHLDA2 may participate in PE pathogenesis.