Betamethasone reverses AVP-induced dysfunction in trophoblast cells

Abstract

Previously published data demonstrate that arginine vasopressin (AVP) secretion is elevated throughout gestation in pregnancies affected by preeclampsia. Additionally, chronic infusion of AVP in mice mimics human preeclampsia with pregnancy-specific hypertension, glomerular endotheliosis, proteinuria, and inflammation. In this AVP-infusion mouse model, betamethasone (BMTZ) has been shown to reverse the preeclampsia phenotype. Corticosteroids have previously been used to ameliorate human HELLP syndrome. Steroids have pleotropic therapeutic effects. The mechanism of BMTZ in reversing preeclampsia is unknown. The objective of this study is to determine if BMTZ improves AVP-induced placental dysfunction. Cell migration of HTR8/SVneo cells was analyzed via closure of a 500um gap over 48 hours (Ibidi). Cells were treated with saline, AVP + vasopressin receptor antagonists, and AVP + BMTZ. The area of migration was imaged and calculated (Olympus Cell Sens) and percent change from baseline area was calculated. MMP-9, a marker of inflammation, was measured in cultured media using a commercially available ELISA (Invitrogen). Statistical significance was determined by ANOVA (α=0.05). At 48 hours, AVP demonstrated lower cell migration in comparison to saline (23.8 vs. 32.3 percent change). This dysfunction was reversed with the addition BMTZ (53.8 vs. 32.3 percent change, p< 0.001). Administration of AVP + AVP antagonists (Conivaptan [29.4], Relcovaptan [32.5], Tolvaptan [35.4]) did not significantly affect migration (p >0.05). MMP-9 concentration was significantly lowered in the cell culture supernatant of cells treated with AVP+BMTZ vs. AVP alone (0.242 vs. 0.286 ng/mL, p=0.04). Treating HTR8/Svneo trophoblastic cells in vitro with AVP results in abnormal migration and cytokine expression. BMTZ reverses this AVP-induced dysfunction. In part, this effect may be due to a reversal of MMP-9 associated inflammation. Our results suggest that further investigation is warranted in the use of betamethasone as a novel therapeutic strategy for preeclampsia.