Guadalupe Estrada-Gutierrez

Placental blood leukocytes are functional and phenotypically different than peripheral leukocytes during human labor

Rupture of the fetal membranes during human labor is associated with an inflammatory process localized to the maternal-fetal interface. There is evidence that specific leukocytes subsets are attracted to the choriodecidua, and that after homing they condition a local inflammatory microenvironment, possibly being directly involved in rupture of the membranes. In this study our aim was to compare the phenotypes and function of leukocytes located in the placental intervillous blood with peripheral leukocytes obtained before or after labor, including expression of modulators of inflammation in these cells. Flow cytometry revealed that the proportion of CD14(+) cells is increased in intervillous blood, suggesting the participation of monocytes/macrophages during labor. Real time qRT-PCR showed that at term gestation and particularly during labor, placental blood leukocytes adopt a different expression pattern of pro-inflammatory cytokines than leukocytes in peripheral blood, including IL-1beta and IL-1RA. During labor, both placental and peripheral leukocytes increase their secretion of matrix metalloproteinase-9. Moreover, we showed that placental leukocytes respond differently than peripheral leukocytes to bacterial lipopolysaccharide, secreting differential amounts of TNF-alpha, IL-1beta and IL-6. Finally, a preliminary proteomic characterization of placental leukocytes revealed a significantly higher number of individual proteins than in peripheral leukocytes. Our results support the existence of selective subsets of leukocytes recruited to the maternal-fetal interface that may participate in the triggering of parturition.

Incubation of human chorioamniotic membranes with Candida albicans induces differential synthesis and secretion of interleukin‐1β, interleukin‐6, prostaglandin E2, and 92 kDa type IV collagenase

Ascendant colonization of pathogenic microorganisms from the vagina to the uterus is strongly associated to preterm labour and premature rupture of membranes. This study evaluated the secretion of interleukin (IL)‐1β, tumour necrosis factor (TNF)α, IL‐6, prostaglandin E2 (PGE2), and metalloproteinases 9 and 2 by the human chorioamnion stimulated with Candida albicans. Chorioamniotic membranes were obtained after delivery by elective Cesarean section from women at 37–40 weeks of gestation without evidence of active labour. The membranes were mounted in Transwell devices that form two independent compartments, which allow testing the individual responses and contributions of the amnion and choriodecidua. One million CFU ml−1 of C. albicans was added to either the amniotic or choriodecidual surface and secretions of the markers were measured in both compartments using specific enzyme‐linked immunosorbent assay and zymography. Fetal membranes followed different secretion patterns of proinflammatory cytokines depending on the side to which the stimulus was applied. IL‐1β was produced in higher amounts in the presence of C. albicans when applied to the choriodecidual side; TNFα and IL‐6 secretion did not change in either the amnion or choriodecidual region. PGE2 synthesis depicted a different pattern, the amniotic tissue was more responsive than the choriodecidual tissue, and this response tended to be higher even when only the amniotic side was stimulated. Matrix metalloproteinases (MMP)‐9 increased after stimulation, being the choriodecidua its main source. Selective stimulation with C. albicans induced a differential secretion of IL‐1β, PGE2, and MMP‐9, resulting from a cooperative and bidirectional communication between the amnion and the choriodecidua.

Progesterone Elicits an Inhibitory Effect upon LPS-Induced Innate Immune Response in Pre-Labor Human Amniotic Epithelium

Infection of human fetal membranes elicits secretion of pro‐inflammatory modulators through its innate immune capacities. We investigated the effect of lipopolysacharide (LPS) and progesterone (P4) upon expression of TLR‐4/MyD88, TNFα, IL‐6, IL‐8, IL‐10, and HBD2 on the human amniotic epithelium.

Preserved Ex Vivo Inflammatory Status in Decidual Cells from Women with Preterm Labor and Subclinical Intrauterine Infection

Objective To compare the inflammatory response preserved ex vivo by decidual cells isolated from women who experienced preterm labor with and without subclinical intrauterine infection. Methods Fetal membranes were obtained after cesarean section from 35 women who delivered before 37 weeks of gestation following spontaneous preterm labor, with no clinical evidence of intrauterine infection. Decidua was microbiologically tested and cultured. Concentrations of anti-inflammatory cytokines (IL-2, IL-4, IL-10), pro-inflammatory cytokines (IL-6, IL-8, IL-1β and TNF-α), and matrix metalloproteinases (MMP-1, MMP-2, MMP-3, MMP-7, MMP-8, MMP-9) were measured in the supernatants using Bio-Plex, and prostaglandin E2 (PGE2) was measured by enzyme immunoassay. Results Subclinical infection was confirmed in 10 women (28.5%). Microorganisms isolated were Ureaplasma urealyticum (4), group B streptococci (3), Gardnerella vaginalis (1), and Escherichia coli (2). We found a significant increase of pro-inflammatory cytokines and a significant decrease of anti-inflammatory cytokines in supernatants from decidual cells obtained from women with preterm labor and subclinical intrauterine infection compared to women without infection. Secretion of MMP-1, MMP-8, MMP-9 and PGE2 was significantly higher in infected women. Secretion of IL-8 by decidual cells from infected women persisted upon repeated in vitro culture passages. Conclusions Almost 30% of idiopathic preterm labor cases were associated with subclinical intrauterine infection, and decidual cells isolated from these cases preserved an ex vivo inflammatory status after in vivo bacterial exposure.

Increased Expression of Matrix Metalloproteinase-1 in Systemic Vessels of Preeclamptic Women: A Critical Mediator of Vascular Dysfunction

This study was conducted to determine the following: (1) whether matrix metalloproteinase-1 (MMP-1) is increased in systemic vessels of preeclamptic women, (2) whether this increase might be mediated by neutrophils, and (3) whether MMP-1 could be responsible for vascular dysfunction. Omental arteries and plasma were collected from healthy pregnant and preeclamptic women. Omental arteries were evaluated for gene and protein expression of MMP-1, collagen type 1α, tissue inhibitor of metalloproteinase-1, and vascular reactivity to MMP-1. Gene and protein expression levels were also evaluated in human vascular smooth muscle cells (VSMCs) co-cultured with activated neutrophils, reactive oxygen species, or tumor necrosis factor α. Vessel expression of MMP-1 and circulating MMP-1 levels were increased in preeclamptic women, whereas vascular expression of collagen or tissue inhibitor of metalloproteinase-1 were down-regulated or unchanged. In cultured VSMCs, the imbalance in collagen-regulating genes of preeclamptic vessels was reproduced by treatment with neutrophils, tumor necrosis factor α, or reactive oxygen species. Chemotaxis studies with cultured cells revealed that MMP-1 promoted recruitment of neutrophils via vascular smooth muscle release of interleukin-8. Furthermore, MMP-1 induced vasoconstriction via protease-activated receptor-1, whose expression was significantly increased in omental arteries of preeclamptic women and in VSMCs co-cultured with neutrophils. Collectively, these findings disclose a novel role for MMP-1 as a mediator of vasoconstriction and vascular dysfunction in preeclampsia.

Tissue-specific human beta-defensins (HBD)-1, HBD-2 and HBD-3 secretion profile from human amniochorionic membranes stimulated with Candida albicans in a two-compartment tissue culture system

BackgroundDuring intrauterine infection, amniochorionic membranes represent a mechanical and immunological barrier against dissemination of infection. Human beta defensins (HBD)-1, HBD-2, and HBD-3 are key elements of innate immunity that represent the first line of defense against different pathogen microorganisms associated with preterm labor. The aim of this work was to characterize the individual contribution of the amnion (AMN) and choriodecidua (CHD) regions to the secretion of HBD-1, HBD-2 and HBD-3, after stimulation with Candida albicans.MethodsFull-thickness human amniochorionic membranes were obtained after delivery by elective cesarean section from women at 37-40 wk of gestation with no evidence of active labor. The membranes were cultured in a two-compartment experimental model in which the upper compartment is delimited by the amnion and the lower chamber by the choriodecidual membrane. One million of Candida albicans were added to either the AMN or the CHD face or to both and compartmentalized secretion profiles of HBD-1, HBD-2, and HBD-3 were quantified by ELISA. Tissue immunolocalization was performed to detect the presence of HBD-1, -2, -3 in tissue sections stimulated with Candida albicans.ResultsHBD-1 secretion level by the CHD compartment increased 2.6 times (27.30 [20.9-38.25] pg/micrograms protein) when the stimulus with Candida albicans was applied only on this side of the membrane and 2.4 times (26.55 [19.4-42.5] pg/micrograms protein) when applied to both compartments simultaneously. HBD-1 in the amniotic compartment remained without significant changes. HBD-2 secretion level increased significantly in the CHD when the stimulus was applied only to this region (2.49 [1.49-2.95] pg/micrograms protein) and simultaneously to both compartments (2.14 [1.67- 2.91] pg/micrograms protein). When the stimulus was done in the amniotic compartment HBD-2 remained without significant changes in both compartments. HBD-3 remained without significant changes in both compartments regardless of the stimulation modality. Localization of immune-reactive forms of HBD-1, HBD-2, and HBD-3 was carried out by immunohistochemistry confirming the cellular origin of these peptides.ConclusionSelective stimulation of amniochorionic membranes with Candida albicans resulted in tissue-specific secretion of HBD-1 and HBD-2, mainly in the CHD, which is the first region to become infected during an ascending infection.

Tissue-specific IL-10 secretion profile from term human fetal membranes stimulated with pathogenic microorganisms associated with preterm labor in a two-compartment tissue culture system.

Abstract Objective: Interleukin (IL)-10 is a cytokine with anti-inflammatory properties that plays pivotal roles in immune recognition and maintenance of pregnancy, limiting the harmful effects of pro-inflammatory modulators. The aim of this work was to characterize the contribution of amnion and choriodecidua regions of the human fetal membranes in the production of IL-10 after selective stimulation with Candida albicans, Gardnerella vaginalis and Streptococcus agalactiae. Methods: Pre-labor human fetal membranes were cultured in a two-compartment tissue culture system and stimulated with 1 × 106 CFU/ml of each pathogen added to either the amniotic or choriodecidual region or both. Results: Candida albicans and G. vaginalis were the pathogens most effective in inducing IL-10 secretion, increasing 20 and 10 times, respectively, the levels of this cytokine in the choriodecidual compartment. Stimulation with S. agalactiae was effective only in the choriodecidual region, increasing two times IL-10 concentration. Conclusions: Synthesis and secretion of IL-10 in response to three different pathogens associated with intrauterine infection and preterm birth are differential and depend on the nature of the microorganism and initial contact region.

Effects of the plasmid-encoded toxin of enteroaggregative Escherichia coli on focal adhesion complexes

Enteroaggregative Escherichia coli (EAEC) is an emerging diarrheal pathogen. Many EAEC strains produce the plasmid-encoded toxin (Pet), which exerts cytotoxic effects on human intestinal tissue. Pet-intoxicated HEp-2 cells exhibit rounding and detachment from the substratum, accompanied by loss of F-actin stress fibers and condensation of the spectrin-containing membrane cytoskeleton. Although studies suggest that Pet directly cleaves spectrin, it is not known whether this is the essential mode of action of the toxin. In addition, the effects of Pet on cytoskeletal elements other than actin and spectrin have not been reported. Here, we demonstrate by immunofluorescence that upon Pet intoxication, HEp-2 and HT29 cells lose focal adhesion complexes (FAC), a process that includes the redistribution of focal adhesion kinase (FAK), α-actinin, paxillin, vinculin, F-actin, and spectrin itself. This redistribution was coupled with the depletion of phosphotyrosine labeling at FACs. Immunoblotting and immunoprecipitation experiments revealed that FAK was tyrosine dephosphorylated, before the redistribution of FAK and spectrin. Moreover, phosphatase inhibition blocked cell retraction, suggesting that tyrosine dephosphorylation is an event that precedes FAK cleavage. Finally, we show that in vitro tyrosine-dephosphorylated FAK was susceptible to Pet cleavage. These data suggest that mechanisms other than spectrin redistribution occur during Pet intoxication.

Maternal and Fetal Lipid and Adipokine Profiles and Their Association with Obesity

Background. Maternal metabolic changes impact fetal metabolism resulting in a higher risk for developing chronic diseases later in life. The aim of this study was to assess the association between maternal and fetal adipokine and lipid profiles, as well as the influence of maternal weight on this association. Methods. Healthy pregnant women at term who delivered by C-section were enrolled. Maternal and fetal glucose, lipid profile, adiponectin, leptin, and resistin levels were analyzed by obesity and maternal weight gain. Statistics included descriptives, correlations, and mean differences (SPSS v20.0). Results. Adiponectin and resistin concentrations were higher in fetal blood, while leptin was lower (p < 0.05). A significant inverse association between maternal resistin and fetal LDL-cholesterol (LDL-C) (r = −0.327; p = 0.022) was observed. A positive correlation was found between maternal and fetal resistin (r = 0.358; p = 0.013). Women with excessive weight gain had higher leptin levels and their fetuses showed higher LDL-C levels (p < 0.05). Conclusions. Maternal resistin showed an inverse association with fetal LDL-C, suggesting that maternal adiposity status may play an active role in the regulation of fetal lipid profile and consequently, in fetal programming. Excessive maternal weight gain during pregnancy may exert an effect over metabolic mediators in both mother and newborn.

Galectin-1 reduced the effect of LPS on the IL-6 production in decidual cells by inhibiting LPS on the stimulation of IκBζ

Pregnancy is a complex process where several physiological pathways interact. The down-regulated inflammatory response and the abundance of anti-inflammatory molecules during gestation may explain the acceptance of the fetus and the lack of immune response against it, even though it is a foreign tissue for the mother. NF-κB is a key regulator of the transcription of inflammatory genes, such as IL-8, IL-1β, TNF-α, or IL-6. Increased NF-κB activity that leads to the production of proinflammatory cytokines may induce obstetric disorders, such as preterm birth or abortion. Low activity of this transcription factor is associated with the beneficial anti-inflammatory environment during fetus development until delivery. Galectin-1 (Gal-1) is a lectin-type glycan-binding protein that is able to down-regulate inflammation. It has been shown that Gal-1 is abundantly expressed at the feto-maternal interface in humans, where it promotes maternal immune tolerance to the fetal semi-allograft. Gal-1 tolerance-promoting mechanisms have been established for adaptive immune cells, such as T cells and dendritic cells. However, the role of this lectin has not been established in non-immune cells at the feto-maternal interface. Here, we determined that Gal-1 is able to block the stimulating effect of LPS on IL-6 in human decidua cells. Our results show that Gal-1 acts by inhibiting the stimulation of the LPS-induced IκBζ expression, an NF-κB regulator involved in IL-6 gene transcription.