Study The Molecular Mechanisms Of G- Protein Coupled Receptor 30 On The Pathogenesis Of Preeclampsia

Background:Preeclampsia (PE) is associated with lowered circulating levels of estrogen. The effects of estrogen are normally mediated by the classical estrogen receptors (ERs). Intriguingly, a new estrogen receptor, G-protein coupled receptor 30 (GPR30), has been recently found to play an important role in many estrogenic effects. However, the potential role of GPR30 in PE remains poorly understood.Objective:To evaluate the different expression of GPR30 in placenta, decidua, and umbilical cord tissues, and to explore the effects of G-Protein Coupled Receptor 30(GPR30) on the production of nitric oxide(NO), as well as the relationship with preeclampsia (PE)Methods:22 cases of PE and 21 cases of normal maternal placental, decidua, and umbilical cord tissues were collected in the First Affiliated Hospital of Chongqing Medical University from September 2012 to May 2014. Immunohistochemistry was used to detect the expression of GPR30 in the placental, decidua, and umbilical cord tissues. Human umbilical vein endothelial cells (HUVECs) was used as a cell model of preeclampsia, immunofluorescence and Western blotting were used to detect the expression of GPR30 protein in HUVECs. Western blotting was used to detect the expression of GPR30, p-eNOS (Ser1177), p-PI3K (p85), and p-Akt (Ser473) protein in different treatment groups of HUVECs. Flow cytometry was used to detect the apoptosis of HUVECs, in vitro tube formation assay was used to detect capability of the tube formation of HUVECs and migration assay was used to detect the migration ability of HUVECs.Results: The expression of GPR30 in placental vascular endothelial cells is lower in placentas, decidua, and umbilical cords tissues of PE compare with normotensive controls (P＜0.05). The expression of GPR30 protein was reduced in HUVEC after hypoxia/reoxygenation (H/R) treatment (P＜0.05); The apoptosis of HUVECs was increased with the treatment of inhibitor of GPR30-G15 (P＜0.05); The GPR30 agonist-Gland 17β-estradiol (E2) played protective effects in H/R-exposed HUVECs by protect the capabilities of the tube formation and migration (P＜0.05), while this effect was abolished by G15 (P＜0.05). After hypoxia/reoxygenation (H/R) treatment, the expression of GPR30 and p-eNOS (Ser1177) were significantly decreased than the control group (P＜0.05); while with the GPR30 agonist G1 and 17 β-estradiol (E2) pretreatment, the expression of GPR30, p-PI3K (p85), p-Akt (Ser473), and p-eNOS (Ser1177) compared with H/R group were raised (P＜0.05), the GPR30 inhibitor G15 significantly reduced the expression of these indicators (P<0.05)Conclusion:These findings suggest that the decline expression of GPR30 may play an important role in placental endothelial dysfunction in PE. These results suggest that GPR30 is an important regulator of the NO production in the placenta, the decreased expression of GPR30 may lead to placenta vasomotor dysfunction of PE by down-regulation of NO.