172. Vitamin D decreases gene and protein expression of NLRP3 inflammasome in placental explants cultured with hydrogen peroxide from women with preeclampsia

Abstract

Introduction Pregnancies complicated by preeclampsia (PE) are associated with placental oxidative stress and related to the activation of NLRP3 inflammasome, an important complex for activation of caspase-1, interleukin-1 beta (IL-1β) and high-mobility group box-1 (HMGB1). The hyperactivation of NLRP3 inflammasome in placental tissues may be involved in the huge systemic inflammatory state in PE, which could be modulate by administration of substances with anti-inflammatory properties such as vitamin D (VD). Objectives This study aimed to evaluate vitamin D immunomodulatory effect on the NLRP3 inflammassome in placental explants from normotensive (NT) and preeclamptic women cultured with hydrogen peroxide. Methods Placental explants from 7 PE and 7 NT women in the third trimester of pregnancy were obtained from women undergoing elective cesarean section. Explants were cultured with or without H2O2 and H2O2 plus VD. NLRP3, HMGB1, caspase-1 and IL-1β gene expression were analysed by qPCR. Protein expression were determined by western blotting or ELISA. Results Endogenous gene expression of NLRP3 and HMGB1 were significantly higher in PE than in NT explants. NLRP3, caspase-1, IL-1β and HMGB1 gene expression were higher in cultures treated with H2O2 compared to control cultures, while explants treated with H2O2 plus VD led to lower gene expression in NT and PE groups. High protein expression of NLRP3, caspase-1, IL-1β and HMGB1 was detected in explants cultured with H2O2 compared to controls whereas cultures treated with H2O2 plus VD decreased these protein expression compared to H2O2 stimuli. Conclusion Vitamin D was able to decrease the gene and protein expression of NLRP3 inflammasome and HMGB1 production in placental explants cultured with H2O2 in PE and NT groups. These results suggest that vitamin D may play an immunomodulatory role in the systemic inflammatory response present in preeclampsia. Financial support FAPESP 2016/18155-9 and 2016/23452-2.