Vitamin D decreases expression of NLRP1 and NLRP3 inflammasomes in placental explants from women with preeclampsia cultured with hydrogen peroxide.

This study aimed to evaluate the immunomodulatory effect of vitamin D (VD) on the NLRP1 and NLRP3 inflammasomes in placental explants from preeclamptic (PE) and normotensive (NT) pregnant women. Placental explants from eight PE and eight NT pregnant women were cultured with or without hydrogen peroxide (H2O2), VD or H2O2 + VD. Gene and protein expression of NLRP1, NLRP3, HMGB1, caspase-1, IL-1ß, TNF-α and IL-18 were determined by qPCR and Western blotting/ELISA. Compared to NT pregnant women, the endogenous gene expression of NLRP1, NLRP3, HMGB1, IL-1ß, TNF-α and IL-18 was significantly higher in explants from PE and became decreased after VD treatment. Similarly, VD decreased the protein expression of NLRP1, NLRP3, caspase-1, HMGB1, IL-1ß, TNF-α and IL-18 in PE. Placental explants from NT cultured with H2O2 showed increased gene and protein expression of NLRP1, NLRP3, caspase-1, IL-1ß, TNF-α and HMGB1, while H2O2 was also able to increase TNF-α and caspase-1 gene expression in PE. Treatment with H2O2 + VD decreased gene/protein expression of NLRP1, NLRP3, caspase-1, HMGB1, IL-1ß, TNF-α and IL-18 in PE and NT explants with H2O2. NLRP1 and NLRP3 are upregulated in the PE. VD may play an immunomodulatory role in the placental inflammation and downregulates oxidative stress induced in vitro by H2O2.

Increased expression of NLRP3 inflammasome in placentas from pregnant women with severe preeclampsia.

Preeclampsia is a pregnancy disorder characterized by imbalance between pro- and anti-inflammatory cytokines associated with high plasma levels of uric acid and Interleukin-1 beta (IL-1ß). The inflammasome is a protein complex that mediates innate immune responses via caspase-1 activation promoting secretion of IL-1ß and IL-18 in their active forms, and also release of the high-mobility group box 1 protein (HMGB1). As the placenta seems to play an important role in the pathogenesis of PE, the present study investigated the expression of genes and proteins related to the inflammasome in placentas from pregnant women with severe preeclampsia. Placental tissue was collected from 20 normotensive pregnant women and 20 preeclamptic women, and inflammasome components, NLRP3 (NOD-like receptor family, pyrin domain-containing protein 3), caspase-1, IL-1ß and IL-18, as well as tumor necrosis factor-alpha (TNF-α) and HMGB1 were evaluated by immunohistochemistry, enzyme-linked immunosorbent assay (ELISA) and also quantified by reverse transcription-qPCR (RT-qPCR). Compared with normotensive pregnant women, placenta from women with PE showed a significant increase in NLRP3, caspase-1, IL-1ß, TNF-α and HMGB1 mRNA. Immunohistochemical staining of NLRP3, caspase-1, IL-1ß and TNF-α in placental villi, as well as the levels of caspase-1, IL-1ß, TNF-α and HMGB1 in placental homogenate were significantly higher in the preeclamptic group than in the normotensive group. However, mRNA expression of IL-18 and its protein concentrations were lower in placentas from preeclamptic women. The results suggest that placentas from pregnant women with preeclampsia show higher expression of NLRP3 inflammasome, which may be involved in the exaggerated inflammatory state in preeclampsia.

Association between cytokine profile and transcription factors produced by T-cell subsets in early- and late-onset pre-eclampsia.

Pre-eclampsia (PE) is an obstetric pathology characterized by abnormal activation of the innate and adaptive immune systems dependent on the imbalance of T helper subsets. The present study aimed to evaluate the gene and protein expression of T helper type 1 (Th1)/Th2/Th17/regulatory T (Treg) cell transcription factors in peripheral blood lymphocytes from pregnant women with PE employing quantitative RT-PCR and flow cytometry techniques, as well as the cytokine profile produced by these CD4+ T-cell subsets in the plasma of pregnant women with PE, classified as early-onset PE (n = 20), late-onset PE (n = 20) and normotensive pregnant women (n = 20). Results showed a higher percentage of CD4+ T cells expressing the RORc transcription factor (Th17) and a lower percentage of cells expressing FoxP3 (Treg) in women with early-onset PE compared with late-onset PE and normotensive groups. A lower gene expression of GATA-3 transcription factor was detected in cells of women with early-onset PE compared with the late-onset PE group. Endogenous plasma levels of interleukin-6 (IL-6), IL-17 and tumour necrosis factor-α were significantly higher in the early-onset PE group than in the late-onset PE and normotensive groups, whereas IL-4 (Th2 profile) and IL-22 (Th17 profile), were not significantly different between the studied groups. The endogenous levels of transforming growth factor-ß and IL-10 were significantly lower in the pre-eclamptic than in the normotensive groups of the same gestational age, with a significant difference between early- and late-onset PE. The results show that in women with PE there is an imbalance between inflammatory and anti-inflammatory profiles in CD4+ T-cell subsets, with polarization to Th17 profiles in the early-onset PE, considered as the severe form of PE.