Immunomodulatory effect of vitamin D on the STATs and transcription factors of CD4+ T cell subsets in pregnant women with preeclampsia.

This study evaluated the in vitro modulatory effect of vitamin D (VD) on T cells, by determining the expression of STATs and the transcription factors of each CD4+ T cell subsets. Twenty women with preeclampsia (PE) and 20 normotensive pregnant women were studied. Peripheral blood mononuclear cells were cultured with or without VD to analyse the STATs and transcription factors by flow cytometry, and cytokines production by ELISA. The plasma levels of VD were lower in the PE group. Treatment of cells with VD decreased STAT1/STAT4/T-bet, STAT3/RORγt, and increased STAT6/GATA-3 and STAT5/FoxP3 in preeclamptic women. Treatment with VD also decreased the levels of inflammatory cytokines and increased IL-10 and TGF-ß. This hormone exerts immunomodulatory effects on the STAT signalling pathway, shifting the inflammatory profiles, Th1/Th17 cells to Th2/Treg profiles, and it can be suggested as a promising strategy to regulate the systemic inflammatory response in PE.

Vitamin D decreases cell death and inflammation in human umbilical vein endothelial cells and placental explants from pregnant women with preeclampsia cultured with TNF-α.

This study evaluated the impact of vitamin D on Human Umbilical Vein Endothelial Cells (HUVEC) and inflammation in placental explants from women with preeclampsia (PE). HUVEC and explants from 10 late-onset PE (LOPE), 10 early-onset (EOPE), and 10 normotensive (NT) pregnant women were cultured with/without tumor necrosis factor (TNF-α) and VD. Interleukin-1ß (IL-1ß), 18 (IL-18), TNF-α, and TNF-related apoptosis-inducing ligand (TRAIL) were detected by ELISA. High mobility group box 1 (HMGB1) was determined by qPCR/Western blotting, and cell death by flow cytometry. Statistical significance was accepted at p < .05. Compared to the NT group, the endogenous levels of IL-1ß, TNF-α, and IL-18 were higher in the PE group. The stimulus with TNF-α increased cytokines in NT, TNF-α in EOPE/LOPE, IL-18 in LOPE, and all cytokines in HUVEC. TNF-α+VD treatment decreased cytokines in explant and HUVEC supernatants. TRAIL was higher in EOPE versus NT, while TNF-α increased this receptor in NT versus control. In HUVEC, TNF-α increased TRAIL versus control, and TNF-α+VD decreased levels compared to only TNF-α stimulus. Protein expression of HMGB1 was higher in explant cultures treated with TNF-α and decreased after TNF-α+VD treatment in all groups, and gene/protein expression in HUVEC. Gene expression was elevated in EOPE versus NT and LOPE, and TNF-α increased HMGB1 in NT versus control, while TNF-α+VD decreased mRNA levels in EOPE. TNF-α stimulus increased late apoptosis in HUVEC, while VD increased viability. These in vitro observations suggest that VD administration to women with preeclampsia may be beneficial in reducing placental inflammation and cell death.

Modulatory effects of silibinin in cell behavior during osteogenic phenotype.

Natural molecules, such as flavonoid, are very welcome strategies to modulate bone turnover. This prompted us to comprehend better the effect of silibinin on osteoblast metabolism, mainly considering intracellular pathways able to drive cell adhesion to differentiation. By exploring in vitro approaches, our data show a modulatory effect of the silibinin (200 µg/mL) on the osteoblast intracellular signaling, contributing with decisive pathways governing cell adhesion, differentiation, and further mineralization, recapitulating important stages of osteogenesis. Within the first 24 hours of adhesion (acute stage), osteoblasts respond to silibinin by rearranging their cytoskeleton and start mechanisms responsible to extracellular matrix (ECM) remodeling, which reach intense profile at 28 days of treatment (chronic stage) by favoring matrix metalloproteinases (MMPs-2, and -9) activities, concomitant to mineralizing phenotype. Importantly, silibinin seems to reprogram genes related to inflammatory landscape and significantly upmodulating osteoprotegerin (>25 fold-changes), signaling molecule involved with osteoclastogenesis. Altogether, our results show for the first time that silibinin drives in vitro osteoblast differentiation by requiring specific intracellular signaling. In conjunction, this molecular landscape contributes to understand the effect of silibinin on osteoblasts performance and open novel therapeutic possibilities to silibinin in bone disorders, such as osteoporosis.

Silibinin Downregulates the NF-κB Pathway and NLRP1/NLRP3 Inflammasomes in Monocytes from Pregnant Women with Preeclampsia.

Preeclampsia (PE) is a human pregnancy-specific syndrome with abnormal activation of cells from the innate immune system. The present study evaluated whether silibinin (SB) treatment of monocytes from preeclamptic women could modulate NLRP1 and NLRP3 inflammasomes as well as TLR4/NF-κB pathway activation. Peripheral blood monocytes from 20 preeclamptic and 20 normotensive (NT) pregnant women, as well as the THP-1 cell line, were cultured with or without monosodium urate (MSU) or SB. NLRP1, NLRP3, Caspase-1, TLR4, MyD88, NF-κB, IL-1ß, IL-18, TNF-α and IL-10 gene expression by monocytes was analysed by quantitative real-time polymerase chain reaction (qPCR), while inflammatory cytokine production and p65NF-κB activity were determined by enzyme-linked immunosorbent assays (ELISAs). TLR4/MyD88/NF-κB and NLRP1/NLRP3 inflammasomes pathways in THP-1 cells were evaluated by flow cytometry and western blot respectively. Compared with NT women, monocytes from preeclamptic women showed The Ethics Committee of the Botucatu Medical School approved the study (protocol number 2.333.216)higher endogenous activation of NLRP1/NLRP3 inflammasomes and the TLR4/NF-κB pathway as well as higher gene and protein expression of IL-1ß, IL-18 and TNF-α, and lower expression of IL-10. Monocyte stimulation with MSU increased inflammation-related genes as well as NF-κB activity. In vitro, SB treatment of monocytes from preeclamptic women reduced the basal activation of these cells by decreasing NLRP1/NLRP3 inflammasomes and p65NF-κB activity. THP-1 cells exhibited a similar immunological response profile to monocytes from preeclamptic women when cultured with or without MSU or SB. These results suggest uric acid participates in the systemic inflammatory response characteristic of preeclampsia and that in vitro SB treatment can modulate the sterile inflammation established in monocytes from preeclamptic women.

Elevated hyaluronan and extracellular matrix metalloproteinase inducer levels in women with preeclampsia.

PURPOSE: Preeclampsia (PE) is a specific syndrome of pregnancy clinically identified by hypertension and proteinuria from the 20th week of gestation associated with a systemic inflammatory response and oxidative stress. While pro-inflammatory cytokines have been extensively studied in PE, other factors in the circulation that also influence the magnitude of inflammation have received much less attention. The present study compared serum concentrations of five immune-regulatory compounds in normotensive pregnant women and in women with gestational hypertension (GH) or PE. METHODS: Sixty women with PE, 53 with GH and 40 normotensive women paired by gestational age were evaluated. Sera were evaluated for concentrations of extracellular matrix metalloproteinase inducer (EMMPRIN), hyaluronan, gelsolin, visfatin and histone 2B by ELISA. Differences between groups were analyzed by nonparametric tests, with a significance level of 5%. RESULTS: Increased levels of EMMPRIN and hyaluronan were present in preeclamptic women as compared to the GH and normotensive groups. There was no difference between groups in gelsolin, visfatin or histone 2B. CONCLUSION: Increased release of EMMPRIN and hyaluronan may contribute to an elevated pro-inflammatory response and tissue damage in women with PE.

Increase of autophagy marker p62 in the placenta from pregnant women with preeclampsia.

Preeclampsia (PE) is a multisystemic disorder characterized by abnormal placentation. Autophagy is a lysosomal degradation pathway that removes protein aggregates and damaged organelles, and it seems to be essential for cell survival during stress, hypoxia, and for implantation and development of the placenta. p62/SQSTM1 is an autophagy marker that not only binds proteins destined for elimination but is also constitutively degraded by this mechanism. Considering that the placenta plays an important role in the pathogenesis of PE, the present study aimed to evaluate the gene and protein expression of p62/SQSTM1 in placentas from pregnant women with PE. Placental tissues from 20 women with PE classified into three groups according to gestational age, 27-31 weeks (n = 8); 32-36 weeks (n = 6); 37-39 weeks (n = 6), and 20 normotensives (NT) pregnant women were collected and employed for p62/SQSTM1 expression by quantitative polymerase chain reaction (qPCR), immunohistochemistry and enzyme-linked immunosorbent assay (ELISA) techniques. p62/SQSTM1 mRNA levels were significantly lower, while protein expression was significantly higher in the placenta of pregnant women with PE than in NT pregnant women, and these results remained similar after separating the groups by gestational age. In conclusion, the results suggest that there is a reduction of autophagic activity in pregnant women with PE. Studies involving cross-talk between autophagy, inflammasomes, nuclear transcription factor (NF-κB) activation pathways, and aggregation of protein in the placenta from women with PE might help to better understand the pathogenesis of this important obstetric pathology.

DAMPs are able to skew CD4+ T cell subsets and increase the inflammatory profile in pregnant women with preeclampsia.

Preeclampsia (PE) is characterized by abnormal activation of the immune system. The intense systemic inflammatory reaction, could be related to the presence of molecules released after cell stress or death, that are capable of inducing inflammation and are known as damage-associated molecular patterns (DAMP). This study evaluated the profile of T cells through the analysis of transcription factors and the cytokines produced after culture with or without DAMPs: heat shock protein 70 (Hsp70), hyaluronan (HA) and monosodium urate (MSU). Twenty pregnant women with PE, 20 normotensive (NT) pregnant women and 20 non-pregnant (NP) women were studied. The results showed polarization toward Th1/Th17 and a decrease in Th2/Treg profiles in preeclamptic women associated with elevated levels of TNF, IFN-γ, and IL-17A and diminished levels of TGF-ß1 and IL-10 when compared to the normotensive group. In addition, preeclamptic women had a higher percentage of cells co-expressing T-bet/GATA-3 and T-bet/RORγt and fewer T-bet/FoxP3 cells when compared to normotensive group. MSU induced an increase in IFN-γ and IL-22 in all studied groups. MSU, HA, and Hsp70 induced significant higher production of TNF in the PE and NP groups. The PE group showed elevated levels of TGF-ß1 after incubation with MSU, HA, and Hsp70, whereas HA and Hsp70 decreased TGF-ß1 production in NT group. The results suggest that these alarmins may play a role in the activation of innate and adaptive immune systems by skewing CD4 + T cells and increasing the release of inflammatory cytokines, thereby contributing to the pathogenesis of this important syndrome.

Inflammasomes in placental explants of women with preeclampsia cultured with monosodium urate may be modulated by vitamin D.

OBJECTIVES: Preeclampsia (PE) is an important syndrome of gestation characterized by placental and systemic inflammation. High plasma concentration of uric acid are frequently associated with inflammation and endothelial dysfunction and may contribute to PE pathogenesis. This study aimed to evaluate the vitamin D (VD) immunomodulatory effect on the NLRP1/NLRP3 inflammasomes in placental explants from preeclamptic (PE) and normotensive (NT) pregnant women. STUDY DESIGN: Placental explants from 10 late-onset PE (LOPE), 10 early-onset PE (EOPE), and 10 NT pregnant women were cultured with or without monosodium urate (MSU) and VD. MAIN OUTCOME MEASURES: Gene and protein expression of NLRP1, NLRP3, HMGB1, caspase-1, interleukin-1 beta (IL-1ß), and IL-18 were determined by quantitative PCR and Western blotting/ELISA. Statistical significance was accepted at p < 0.05. RESULTS: Basal gene and protein expression of NLRP1/NLRP3 and IL-1ß, IL-18 and HMGB1 were significantly higher in explants from EOPE compared to LOPE and NT pregnant women. In addition, culture with MSU increased these inflammatory markers, and concomitant treatment with MSU+VD decreased this effect. CONCLUSIONS: The results demonstrated that NLRP1 and NLRP3 inflammasomes are upregulated in the placental tissue of EOPE women, associated with high production of inflammatory cytokines. The in vitro treatment with VD downregulated placental inflammasomes induced by MSU, suggesting its immunomodulatory role in the systemic inflammation of PE.

Silibinin downregulates the expression of the Th1 and Th17 profiles by modulation of STATs and transcription factors in pregnant women with preeclampsia.

Preeclampsia (PE) is a multifactorial disease that is characterized by inflammation. Some of the factors responsible for this inflammation are the cells of the innate and adaptive immune systems and their interactions. The use of natural products, such as silibinin (SB), can contribute to the control of this inflammation and gestational success. The present study evaluated whether the flavonoid SB has an in vitro immunomodulatory effect on the signal transducers and transcription activators (STATs) signaling pathway and transcription factors of CD4+ T cell subsets obtained from preeclamptic and normotensive (NT) pregnant women. Peripheral blood mononuclear cells (PBMCs) from 18 preeclamptic and 18 NT pregnant women were cultured with and without SB to analyze the expression of STATs and transcription factors by flow cytometry, and cytokines were measured in the culture supernatant by ELISA. The results showed that treating cells with SB decreased STAT1/ STAT4/T-bet and STAT3/RORγt, which characteristic of Th1 and Th17 inflammatory profiles, as well as increased STAT6/GATA-3 and STAT5/FoxP3 of anti-inflammatory and regulatory profiles, respectively. In addition, PBMCs from preeclamptic women treated with SB released lower concentrations of inflammatory cytokines and higher levels of IL-10 and TGF-ß. Therefore, SB plays an immunomodulatory role on CD4+ T cell subsets in PE, leading to the downregulation of inflammatory profiles and upregulation of anti-inflammatory and regulatory profiles. More studies are necessary to better understand the modulation of CD4+ T cell subsets by the JAK/STAT and NF-κB pathways in this gestational pathology.

Granulocyte macrophage colony-stimulating factor enhances the modulatory effect of cytokines on monocyte-derived multinucleated giant cell formation and fungicidal activity against Paracoccidioides brasiliensis.

Multinucleated giant cells (MGC) are cells present in characteristic granulomatous inflammation induced by intracellular infectious agents or foreign materials. The present study evaluated the modulatory effect of granulocyte macrophage colony-stimulating factor (GM-CSF) in association with other cytokines such as interferon-gamma (IFN-γ), tumour necrosis factor-alpha, interleukin (IL)-10 or transforming growth factor beta (TGF-ß1) on the formation of MGC from human peripheral blood monocytes stimulated with Paracoccidioides brasiliensis antigen (PbAg). The generation of MGC was determined by fusion index (FI) and the fungicidal activity of these cells was evaluated after 4 h of MGC co-cultured with viable yeast cells of P. brasiliensis strain 18 (Pb18). The results showed that monocytes incubated with PbAg and GM-CSF plus IFN-γ had a significantly higher FI than in all the other cultures, while the addition of IL-10 or TGF-ß1 had a suppressive effect on MGC generation. Monocytes incubated with both pro and anti-inflammatory cytokines had a higher induction of foreign body-type MGC rather than Langhans-type MGC. MGC stimulated with PbAg and GM-CSF in association with the other cytokines had increased fungicidal activity and the presence of GM-CSF also partially inhibited the suppressive effects of IL-10 and TGF-ß1. Together, these results suggest that GM-CSF is a positive modulator of PbAg-stimulated MGC generation and on the fungicidal activity against Pb18.

Vitamin D modulates the transcription factors of T cell subsets to anti-inflammatory and regulatory profiles in preeclampsia.

Vitamin D (VD) is a multifunctional prohormone and low VD status in pregnancy may contribute to the risk of adverse perinatal outcomes, such as preeclampsia (PE). This molecule may modulate the polarization of T cell subsets during gestation. This study evaluated the in vitro immunomodulatory effect of VD [1,25(OH)2D3] on the gene expression of transcription factors and on cytokine production by T cell subsets. Twenty pregnant women with PE and twenty normotensive (NT) pregnant women were studied. Plasma concentration of VD, [25(OH)D3], was evaluated by chemiluminescence. PBMCs from preeclamptic and NT pregnant women were cultured in the absence or presence of VD to determine gene expression of T-bet (Th1), GATA-3 (Th2), RORγt, and RUNX1 (Th17), FoxP3 (regulatory T cell- Treg), and the receptors of VD (VDR) and IL-23 (IL-23R) by quantitative PCR. The concentration of cytokines in the PBMC supernatant culture was determined by cytometric bead array and ELISA immunoassay. The results showed that plasmatic levels of VD were significantly lower in the PE group. The treatment of PBMCs from PE pregnant women with VD induced downregulation of genes related to inflammatory profiles (Th1 and Th17), as well as an increase of the Th2 and Treg profiles. Thus, VD treatment decreased the release of IFN-γ, TNF-α, IL-17, IL-6, and IL-23 while it increased the levels of IL-10 in the PE group. VD induces an immunomodulatory effect in T cell subsets from pregnant women with PE, polarizing these cells to an anti-inflammatory and regulatory profile.

Association between Adverse Maternal Clinical Outcomes and Imbalance of Cytokines and Angiogenic Factors in Preterm Preeclampsia.

OBJECTIVE: Preeclampsia (PE) is a pregnancy-specific syndrome characterized by abnormal levels of cytokines and angiogenic factors, playing a role in the disease development. The present study evaluated whether immunological markers are associated with the gestational age and with the disease severity in preeclamptic women. METHODS: Ninety-five women who developed PE were stratified for gestational age as preterm PE (< 37 weeks) and term PE (≥ 37 weeks of gestation) and compared for disease severity as well as plasma concentration of angiogenic factors and cytokines. The concentrations of placental growth factor (PlGF), vascular endothelial growth factor (VEGF), Fms-like soluble tyrosine kinase (sFlt-1) and soluble endoglin (sEng), as well as the cytokines, tumor necrosis factor-α (TNF-α) and interleukin 10 (IL-10), were determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: The comparison between preeclamptic groups showed a higher percentage of severe cases in preterm PE (82.1%) than in term PE (35.9%). Similarly, the concentrations of TNF-α, sFlt-1, and sEng, as well as TNF-α/IL-10 and sFlt-1/PlGF ratios were significantly higher in the preterm PE group. In contrast, concentrations of PlGF, VEGF, and IL-10 were significantly lower in women with preterm PE. Negative correlations between TNF-α and IL-10 (r = 0.5232) and between PlGF and sFlt1 (r = -0.4158) were detected in the preterm PE. CONCLUSION: In pregnant women with preterm PE, there is an imbalance between immunological markers, with the predominance of anti-angiogenic factors and TNF-α, associated with adverse maternal clinical outcomes.

OBJETIVO: A pré-eclâmpsia (PE) é uma síndrome específica da gravidez caracterizada por níveis anormais de citocinas e fatores angiogênicos, que desempenham um papel no desenvolvimento da doença. Este estudo avaliou se os marcadores imunológicos estão associados à idade gestacional e à gravidade da doença em mulheres com pré-eclâmpsia. MéTODOS: Noventa e cinco mulheres que desenvolveram PE foram estratificadas pela idade gestacional em PE pré-termo (< 37 semanas) e PE a termo (≥ 37 semanas de gestação) e comparadas quanto à gravidade da doença, bem como à concentração plasmática de fatores angiogênicos e citocinas. As concentrações de fator de crescimento placentário (PlGF), fator de crescimento endotelial vascular (VEGF), tirosina quinase solúvel semelhante a Fms (sFlt-1) e endoglina solúvel (sEng), bem como as citocinas, fator de necrose tumoral alfa (TNF- α) e interleucina 10 (IL-10), foram determinados porensaio de imunoabsorção enzimática (ELISA, na sigla em inglês). RESULTADOS: A comparação entre os grupos com pré-eclâmpsia mostrou maior porcentagem de casos graves em PE pré-termo (82,1%) do que em PE a termo (35,9%). Da mesma forma, as concentrações de TNF-α, sFlt-1 e sEng, bem como as razões TNF-α/IL-10 e sFlt-1/PlGF foram significativamente maiores no grupo de PE pré-termo. Em contraste, as concentrações de PlGF, VEGF e IL-10 foram significativamente menores em mulheres com PE pré-termo. Correlações negativas entre TNF-α e IL-10 (r = 0.5232) e entre PlGF e sFlt1 (r = −0.4158) foram detectadas no grupo de PE pré-termo. CONCLUSãO: Em gestantes com PE pré-termo, ocorre um desequilíbrio entre os marcadores imunológicos, com predomínio de fatores antiangiogênicos e TNF-α, associados a desfechos clínicos maternos adversos.

Increased TLR4 pathway activation and cytokine imbalance led to lipopolysaccharide tolerance in monocytes from preeclamptic women.

Preeclampsia (PE) is a pregnancy syndrome characterized by a systemic inflammatory response, and endogenous activation of monocytes. This study aimed to determine whether the activation of monocytes from preeclamptic women might interfere with the response to lipopolysaccharide (LPS)-in vitro stimulation. Fifty-two preeclamptic women and 32 normotensive (NT) pregnant women were included. Monocytes from peripheral blood were cultured with or without LPS. TLR4 expression was analyzed by flow cytometry, NF-κB activity was determined in nuclear extracts and cytokines production was evaluated by ELISA. Endogenous TLR4 ligands such as Hyaluronan, HMGB1 and Hsp70 were determined in plasma. The endogenous TLR4 expression and activation of NF-κB were statistically higher in monocytes from women with PE compared to NT group. Early-onset PE showed higher TLR4 expression compared to late-onset PE. Plasma levels of Hyaluronan, HMGB1, and Hsp70, as well as endogenous production of inflammatory cytokines, were elevated whilst lower production of IL-10 was observed in the PE group. After culture with LPS, monocytes presented lower NF-κB activation, TNF-α and IL-12 production in PE groups than in the NT group. The study demonstrates endogenous activation of monocytes from preeclamptic women, accompanied by higher expression of TLR4, NF-κB activation and elevated production of pro-inflammatory cytokines. The higher plasma levels of the TLR4 ligands hyaluronan, HMGB1 and hsp70, as well as the high concentration of TNF-α endogenously produced by monocytes, could induce the LPS tolerance phenomenon in these cells. These results suggest that monocytes play an important role in the maternal excessive systemic inflammatory response in PE.

Silibinin induces in vitro M2-like phenotype polarization in monocytes from preeclamptic women.

Preeclampsia (PE) is a pregnancy-specific syndrome featuring intense activation of circulating monocytes and an imbalance between pro- and anti-inflammatory cytokines. The present study evaluated the immunomodulatory effect of silibinin (Sb) on the expression of surface markers and the nuclear transcription factor NF-κB signalling pathway of monocytes from preeclamptic women. Monocytes were cultured with or without Sb, and the mean fluorescence intensity of the surface molecules TLR4, CD64, and CD163 as well as the intracellular transcription factors IκB-α and NF-κBp65 was analysed by flow cytometry. The concentration of cytokines in the monocyte culture supernatant was determined by cytometric bead array and ELISA immunoassay. The results showed that the in vitro treatment of monocytes from preeclamptic women with Sb downregulated the endogenous activation of NF-κB and the expression of surface receptors TLR4 and CD64, and reduced the synthesis of the pro-inflammatory cytokines interleukin 1 (IL-1ß), IL-6, IL-8, IL-12p70, IL-23, and tumour necrosis factor alpha (TNF-α) compared with cultures not treated with Sb. The presence of this flavonoid in monocyte cultures increased the expression of CD163 and IκBα and the release of IL-10 and transforming growth factor beta (TGF-ß) in the culture supernatants, polarising these cells from the M1-like profile to the M2-like profile. The anti-inflammatory activity of Sb on the NF-κB activation pathway and induction of cell polarisation to the M2 profile was confirmed by an in vitro assay using monocytes from healthy, non-pregnant women. Treatment of monocytes from preeclamptic women with Sb polarises the cells to the M2-like phenotype, suggesting that this flavonoid has an immunomodulatory effect on the sterile inflammation characteristic of PE.

Interleukin-6 treatment enhances human monocyte permissiveness for Paracoccidioides brasiliensis growth by modulating cytokine production.

The effect of interleukin (IL)-6 on cytokine production was evaluated in human monocyte cultures infected with the virulent strain of Paracoccidioides brasiliensis (Pb18). Peripheral blood monocytes from healthy individuals were preincubated for 24 h with or without human recombinant IL-6, and then challenged with Pb18 for 4 h and 18 h. P. brasiliensis growth was assessed by viable fungi recovery from co-cultures after plating on BHI-agar. Moreover, tumor necrosis factor-alpha (TNF-alpha), IL-6 and IL-10 production in supernatant cultures was determined by enzyme immunoassay (ELISA). Monocyte preincubation with IL-6, and challenged with Pb18 for 4 h, led to significantly higher fungi recovery compared to non-treated co-cultures. The pretreatment of monocytes with IL-6 induced an inhibitory effect on TNF-alpha and IL-10 production during 18 h fungal infection. Otherwise, an autocrine stimulatory effect on IL-6 production was detected at 4 h and 18 h as represented by an elevation in IL-6 levels. The reduction in TNF-alpha levels and stimulation of IL-6 production induced by previous IL-6 treatment might be responsible for a significant increase in fungal growth in human monocytes. The results suggest that IL-6, by exerting a modulatory effect on cytokines production, makes monocyte more permissive for fungal growth.

Interleukin-15 increases Paracoccidioides brasiliensis killing by human neutrophils.

Interleukin-15 is a cytokine produced by a wide range of different cell types, including macrophages, in response to lipopolysaccharide or microbial infection. This cytokine may play a crucial role in the activation of phagocytic cells against pathogens, especially during innate immune response. The effects of IL-15 on human polymorphonuclear leukocyte fungicidal activity against a highly virulent Paracoccidioides brasiliensis strain were investigated. Pretreatment of human neutrophils from healthy individuals with IL-15 for 18 hours increased cell fungicidal activity in a dose-dependent manner. In addition, the exposure to IL-15 induced an increase in neutrophil oxidative burst as evaluated by superoxide anion and H(2)O(2) release. Catalase inhibited fungicidal activity supporting a role for H(2)O(2) in fungus killing. In contrast, IL-8 and TNF-alpha levels were not affected by IL-15 suggesting that its effects were not mediated by these cytokines. Together, these results show that IL-15 is a potent stimulant of antifungal activities in human neutrophils, at least in part by a mechanism dependent on oxidative metabolism.

Platelet aggregation and TGF-beta(1) plasma levels in pregnant women with preeclampsia.

OBJECTIVES: Platelets and transforming growth factor-beta(1) (TGF-beta(1)) are thought to be involved in the pathogenesis of preeclampsia. Our objectives were to determine plasma concentration of TGF-beta(1) in normotensive and preeclamptic women in the third trimester of pregnancy and to evaluate the correlation of TGF-beta(1) plasma levels with platelet count and agonist-induced aggregation capacity. METHODS: Thirty-three women with preeclampsia were compared with 36 healthy women with uncomplicated pregnancies. Peripheral venous blood samples were obtained, and TGF-beta(1) plasma levels measured by an enzyme-linked immunoassay. Platelet aggregation was induced by the agonist agents adenosine diphosphate (ADP), collagen and epinephrine, and was determined in platelet-rich plasma by aggregometry. RESULTS: Plasma concentrations of active TGF-beta(1) were significantly higher in preeclamptic women (10.41+/-2.07ng/mL) compared with normotensive pregnant women (7.01+/-3.29ng/mL). Platelet number and platelet agonist-induced aggregation percent were significantly lower in patients with preeclampsia than in healthy pregnant women. A significant correlation was observed between TGF-beta(1) plasma levels and platelet agonist-induced aggregation percent as between plasma levels of TGF-beta(1) and platelet number in preeclamptic patients. CONCLUSION: The association between impairment in platelet responsiveness and higher levels of TGF-beta(1) in the plasma of patients with preeclampsia suggests that this cytokine may play a role in the pathophysiological events of preeclampsia that are dependent on platelet activation.

Hydrogen peroxide-mediated oxidative stress induces inflammasome activation in term human placental explants.

BACKGROUND: The placenta is a multifunctional organ that can suffer with imbalances between pro- and antioxidant molecules, contributing for inflammatory imbalance. The inflammation generated by oxidative stress may induce inflammasome activation, an essential complex for pro-inflammatory cytokine production. OBJECTIVE: The aim of this study was to evaluate whether hydrogen peroxide (H2O2) mediated oxidative stress induces inflammasome activation on placental explants. STUDY DESIGN: Tissue cultures of placental explants obtained from normotensive pregnant women were performed in different concentrations of H2O2. Gene expressions of NLRP3, caspase-1, IL-1ß, TNF-α and IL-10 were evaluated by qPCR. Superoxide dismutase (SOD), catalase, Heat shock protein 70 (Hsp70), Caspase-1, TNF-α, IL-1ß, IL-10 and human Chorionic Gonadotropin (hCG) were determined by ELISA. RESULTS: Concentrations of catalase, Hsp70, hCG and SOD were higher in cultures with 100 and 1000 µM H2O2 compared to controls. Gene and protein expressions of TNF-α and IL-1ß were elevated in cultures with 1000 µM H2O2 compared to controls. This concentration led to inflammasome activation, by increasing gene expressions of NLRP3, caspase-1 and IL-1ß. In contrast, gene and protein expressions of IL-10 were reduced at 100 and 1000 µM H2O2. Protein expression of caspase-1 was higher in cultures of 100 µM H2O2 compared to controls. Treatment with Glybenclamide at 200 µM was used to prevent NLRP3 inflammasome activation. This concentration reduced protein expression of caspase-1 compared to culture with only H2O2 and control cultures. CONCLUSIONS: Our results confirm that H2O2 induces oxidative stress on placental explants and demonstrate that cell responses to this stress involve inflammasome activation.

Chloroquine is therapeutic in murine experimental model of paracoccidioidomycosis.

Chloroquine, due to its basic properties, has been shown to prevent the release of iron from holotransferrin, thereby interfering with normal iron metabolism in a variety of cell types. We have studied the effects of chloroquine on the evolution of experimental paracoccidioidomycosis by evaluating the viable fungal recovery from lung, liver and spleen from infected mice and H(2)O(2), NO production, tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-6, IL-10 levels and transferrin receptor (TfR) expression from uninfected and infected peritoneal macrophages. Chloroquine caused a significant decrease in the viable fungal recovery from all organs tested, during all periods of evaluation. Peritoneal macrophages from chloroquine-treated infected mice showed higher H(2)O(2) production and TfR expression, and decreased levels of NO, endogenous and stimulated-TNF-alpha, IL-6 and IL-10 during the three evaluated periods. However, despite its suppressor effects on the macrophage function, the chloroquine therapeutic effect upon murine paracoccidioidomycosis was probably due to its effect on iron metabolism, blocking iron uptake by cells, and consequently restricting iron to fungus growth and survival.