P 11 Hydrogen peroxide-induced inflammation and decreased vitamin D receptor in placental explants

Abstract

Introduction Placental oxidative stress has been associated with the pathogenesis of preeclampsia (PE). The imbalance between pro- and anti-inflammatory cytokines in this pathology could be explained by the deficiency of regulatory factors capable of modulating this inflammatory state. Vitamin D may act as anti-inflammatory agent, by regulating the production of inflammatory cytokines and generating an immune tolerogenic environment. Objectives The present study evaluated whether there is association between plasma levels of vitamin D and cytokines, as well as gene expression of vitamin D receptor (VDR) and pro-and anti-inflammatory cytokines by placental explants obtained from normotensive (NT) pregnant women, from women with PE and from NT pregnant women explants treated with or without hydrogen peroxide (H2O2). Methods Blood of 20 PE and 20 NT were collected and plasma concentrations of 25-hydroxyvitamin D [25(OH) D] was evaluated by chemiluminescence. Plasma levels of Interleukin-1 beta (IL-1β), IL-10 and tumor necrosis fator alpha (TNF-α) were detected by ELISA. Placental explants from 15 NT pregnant and 15 PE women in the third trimester of pregnancy were obtained from women undergoing elective cesarean section. NT placental explants were cultured with or without 100 μM H2O2 for 4 h. The gene expression of cytokines (IL-1β, IL-10 and TNF-α) and VDR were determined by qPCR. Differences between groups were analyzed by non-parametric tests with significant level set at 5%. Results Plasma concentration of 25(OH) D and IL-10 was significantly lower in PE group than in the NT group, while levels of TNF-α and IL-1β were higher in PE group. Gene expression of VDR was lower in explants from PE group and in the NT group with H2O2. Gene expression of TNF-α and IL-1β were significantly higher in PE and NT with H2O2. However, IL-10 levels were significantly lower in these groups when compared to normotensive group. Positive correlation between IL-10 and VDR gene expression was observed between normotensive groups (r = 0.8857; p = 0.0333). Conclusion The results showed an imbalance between vitamin D and its receptor with cytokine profile in explants from preeclamptic women as well as in placental explants obtained from NT pregnant women and submitted to oxidative stress and inflammation induced by hydrogen peroxide. Financial support – FAPESP 2016/18155–9