Spatiotemporal patterns of macrophage migration inhibitory factor (Mif) expression in the mouse placenta

<p>Abstract</p> <p>Background</p> <p>Macrophage migration inhibitory factor (MIF) has special pro-inflammatory roles, affecting the functions of macrophages and lymphocytes and counter-regulating the effects of glucocorticoids on the immune response. The conspicuous expression of MIF during human implantation and early embryonic development also suggests this factor acts in reproductive functions. The overall goal of this study was to evaluate Mif expression by trophoblast and embryo placental cells during mouse pregnancy.</p> <p>Methods</p> <p>Mif was immunolocalized at implantation sites on gestation days (gd) 7.5, 10.5, 13.5 and 17.5. Ectoplacental cones and fetal placentas dissected from the maternal tissues were used for Western blotting and qRT-PCR assays on the same gestation days.</p> <p>Results</p> <p>During the post-implantation period (gd7.5), trophoblast giant cells showed strong Mif reactivity. In later placentation phases (gds 10.5-17.5), Mif appeared to be concentrated in the junctional zone and trophoblast giant cells. Mif protein expression increased significantly from gd7.5 to 10.5 (p = 0.005) and from gd7.5 to 13.5 (p = 0.03), remaining at high concentration as gestation proceeded. Higher mRNA expression was found on gd10.5 and was significantly different from gd13.5 (p = 0.048) and 17.5 (p = 0.009).</p> <p>Conclusions</p> <p>The up-regulation of Mif on gd10.5 coincides with the stage in which the placenta assumes its three-layered organization (giant cells, spongiotrophoblast and labyrinth zones), fetal blood circulation begins and population of uNK cells reaches high proportions at the maternal counter part of the placenta, suggesting that Mif may play a role in either the placentation or in the adaptation of the differentiated placenta to the uterus or still in gestational immunomodulatory responses. Moreover, it reinforces the possibility of specific activities for Mif at the maternal fetal interface.</p

Interferon-gamma alters the phagocytic activity of the mouse trophoblast

Interferon-gamma (IFN-gamma) mediates diverse functions in bone marrow-derived phagocytes, including phagocytosis and microbe destruction. This cytokine has also been detected at implantation sites under both physiological and pathological conditions in many different species. At these particular sites, the outermost embryonic cell layer in close contact with the maternal tissues, the trophoblast exhibits intense phagocytic activity. To determine whether IFN-gamma affects phagocytosis of mouse-trophoblast cells, ectoplacental cone-derived trophoblast was cultured and evaluated for erythrophagocytosis. Phagocytic activity was monitored ultrastructurally and expressed as percentage of phagocytic trophoblast in total trophoblast cells. Conditioned medium from concanavalin-A-stimulated spleen cells significantly enhanced trophoblast phagocytosis. This effect was blocked by pre-incubation with an anti-IFN-gamma neutralizing antibody. Introduction of mouse recombinant IFN-gamma (mrIFN-gamma) to cultures did not increase cell death, but augmented the percentage of phagocytic cells in a dose-dependent manner. Ectoplacental cones from mice deficient for IFN-gamma receptor alpha-chain showed a significant decrease of the phagocytosis, even under mrIFN-gamma stimulation, suggesting that IFN-gamma-induced phagocytosis are receptor-mediated. Reverse transcriptase-PCR analyses confirmed the presence of mRNA for IFN-gamma receptor alpha and beta-chains in trophoblast cells and detected a significant increase in the mRNA levels of IFN-gamma receptor beta-chain, mainly, when cultured cells were exposed to IFN-gamma. Immunohistochemistry and Western blot analyses also revealed protein expression of the IFN-gamma receptor alpha-chain. These results suggest that IFN-gamma may participate in the phagocytic activation of the mouse trophoblast, albeit the exact mechanism was not hereby elucidated. Protective and/or nutritional fetal benefit may result from this physiological response. In addition, our data also shed some light on the understanding of trophoblast tolerance to inflammatory/immune cytokines during normal gestation

Expression of dNK cells and their cytokines in twin pregnancies with preeclampsia

OBJECTIVES: To assess the expression of decidual natural killer (dNK) cells and their cytokines in twin pregnancies with preeclampsia. METHODS: This was a prospective case-control study. The inclusion criteria were diamniotic (monochorionic or dichorionic) twin pregnancies in the third trimester with negative serological results for infectious diseases; absence of major fetal abnormalities or twin-twin transfusion syndrome; and no history of administration of corticosteroids in this pregnancy. The control group (CG) included uncomplicated twin pregnancies, and the preeclampsia group (PEG) included twin gestations with clinical and laboratory confirmation of the disease according to well-established criteria. Samples of the decidua were obtained and analyzed by immunohistochemistry for the expression of dNK cells and interleukins (ILs) 10, 12 and 15. In addition, maternal serum samples were collected to determine the levels of these interleukins. RESULTS: Thirty twin pregnancies were selected: 20 in the control group (CG) and 10 in the preeclampsia group (PEG). The PEG showed strong placental immunostaining for IL-15 (p=0.001) and high maternal serum levels of IL-10 (22.7 vs. 11.9 pg/mL, p=0.024) and IL-15 (15.9 vs. 7.4 pg/mL, p=0.024). CONCLUSION: A higher maternal serum concentration of both pro- and anti-inflammatory factors was observed in the twin pregnancies in the PEG. However, no difference in placental expression of IL-10 was found between the groups. These findings may suggest that maternal attempts to balance these interleukins were not sufficient to cause a placental response, and this failure may contribute to the development of preeclampsia

Interferon-gamma alters the phagocytic activity of the mouse trophoblast

Abstract Interferon-gamma (IFN-gamma) mediates diverse functions in bone marrow-derived phagocytes, including phagocytosis and microbe destruction. This cytokine has also been detected at implantation sites under both physiological and pathological conditions in many different species. At these particular sites, the outermost embryonic cell layer in close contact with the maternal tissues, the trophoblast exhibits intense phagocytic activity. To determine whether IFN-gamma affects phagocytosis of mouse-trophoblast cells, ectoplacental cone-derived trophoblast was cultured and evaluated for erythrophagocytosis. Phagocytic activity was monitored ultrastructurally and expressed as percentage of phagocytic trophoblast in total trophoblast cells. Conditioned medium from concanavalin-A-stimulated spleen cells significantly enhanced trophoblast phagocytosis. This effect was blocked by pre-incubation with an anti-IFN-gamma neutralizing antibody. Introduction of mouse recombinant IFN-gamma (mrIFN-gamma) to cultures did not increase cell death, but augmented the percentage of phagocytic cells in a dose-dependent manner. Ectoplacental cones from mice deficient for IFN-gamma receptor alpha-chain showed a significant decrease of the phagocytosis, even under mrIFN-gamma stimulation, suggesting that IFN-gamma-induced phagocytosis are receptor-mediated. Reverse transcriptase-PCR analyses confirmed the presence of mRNA for IFN-gamma receptor alpha and beta-chains in trophoblast cells and detected a significant increase in the mRNA levels of IFN-gamma receptor beta-chain, mainly, when cultured cells were exposed to IFN-gamma. Immunohistochemistry and Western blot analyses also revealed protein expression of the IFN-gamma receptor alpha-chain. These results suggest that IFN-gamma may participate in the phagocytic activation of the mouse trophoblast, albeit the exact mechanism was not hereby elucidated. Protective and/or nutritional fetal benefit may result from this physiological response. In addition, our data also shed some light on the understanding of trophoblast tolerance to inflammatory/immune cytokines during normal gestation.</p

Preeclampsia and superimposed preeclampsia: The same disease? The role of angiogenic biomarkers

<p><i>Objective</i>: We aimed to compare sFlt-1 and placental growth factor (PlGF) levels and the sFlt-1/PlGF ratio between women with preeclampsia and superimposed preeclampsia to, respectively, normotensive and chronic hypertensive ones. <i>Study design</i>: We performed a prospective two-armed cohort in a tertiary teaching hospital in Sao Paulo, Brazil, including 37 normotensive and 60 chronic hypertensive pregnant women. We assessed the serum levels of sFlt-1 and PlGF at 20, 26, 32, and 36 gestational weeks by enzyme-linked immunosorbent assay. <i>Main outcome measures</i>: Having preeclampsia and superimposed preeclampsia. <i>Results</i>: Among normotensive and chronic hypertensive pregnancies, 4 (10.8%) and 14 (23.3%) women developed preeclampsia and superimposed preeclampsia, respectively. Compared with those who remained normotensive, the preeclampsia women presented higher sFlt-1 levels at 32 gestational weeks (4323.45 pg/mL vs. 2242.04 pg/mL, <i>p</i> = 0.019), lower PlGF levels at 20 (183.54 pg/mL vs. 337.38 pg/mL, <i>p</i> = 0.034), 32 (169.69 pg/mL vs. 792.53 pg/mL, <i>p</i> = 0.001), and 36 gestational weeks (252.99 pg/mL vs. 561.81 pg/mL, <i>p</i> = 0.029), and higher sFlt-1/PlGF ratios at 26 (9.02 vs. 1.84, <i>p</i> = 0.004), 32 (23.61 vs. 2.55, <i>p</i> = 0.001), and 36 gestational weeks (49.02 vs. 7.34, <i>p</i> = 0.029). On the other hand, compared with those who remained chronic hypertensive, the superimposed preeclampsia women only presented a higher sFlt-1/PlGF ratio at 32 gestational weeks (9.98 vs. 2.51, <i>p</i> = 0.039). <i>Conclusion</i>: Although angiogenic imbalance is clearly related to preeclampsia, it seems to play a more modest role in superimposed preeclampsia, in which other mechanisms should also be investigated.</p

Obesity induced by high-fat diet promotes insulin resistance in the ovary

Besides the effects on peripheral energy homeostasis, insulin also has an important role in ovarian function. Obesity has a negative effect on fertility, and may play a role in the development of the polycystic ovary syndrome in susceptible women. Since insulin resistance in the ovary could contribute to the impairment of reproductive function in obese women, we evaluated insulin signaling in the ovary of high-fat diet-induced obese rats. Female Wistar rats were submitted to a high-fat diet for 120 or 180 days, and the insulin signaling pathway in the ovary was evaluated by immunoprecipitation and immunoblotting. At the end of the diet period, we observed insulin resistance, hyperinsulinemia, an increase in progesterone serum levels, an extended estrus cycle, and altered ovarian morphology in obese female rats. Moreover, in female obese rats treated for 120 days with the high-fat diet, the increase in progesterone levels occurred together with enhancement of LH levels. The ovary from high-fat-fed female rats showed a reduction in the insulin receptor substrate/phosphatidylinositol 3-kinase/AKT intracellular pathway, associated with an increase in FOXO3a, IL1B, and TNF alpha protein expression. These changes in the insulin signaling pathway may have a role in the infertile state associated with obesity. Journal of Endocrinology (2010) 206, 65-74Fundacao de Amparo a Pesquisa do Estado de Sao Paulo-FAPESP[2006/52163-7]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo-FAPESP[2006/60215-7]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico-CNPq[477906/2006-0]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESPEHAEH

Expression of NADPH Oxidase by Trophoblast Cells: Potential Implications for the Postimplanting Mouse Embryo

Cytochemical localization of hydrogen peroxide-generating sites suggests NADPH (nicotinamide adenine dinucleotide 3-phosphate [ reduced form]) oxidase expression at the maternal-fetal interface. To explore this possibility, we have characterized the expression and activity of the NADPH oxidase complex in trophoblast cells during the postimplantation period. Implantation sites and ectoplacental cones (EPCs) from 7.5-gestational day embryos from CD1 mice were used as a source for expression analyses of NADPH oxidase catalytic and regulatory subunits. EPCs grown in primary culture were used to investigate the production of superoxide anion through dihydroxyethidium oxidation in confocal microscopy and immunohistochemical assays. NADPH subunits Cybb (gp91phox), Cyba (p22phox), Ncf4 (p40phox), Ncf1 (p47phox), Ncf2 (p67phox), and Rac1 were expressed by trophoblast cells. The fundamental subunits of membrane CYBB and cytosolic NCF2 were markedly upregulated after phorbol-12-myristate-13-acetate (PMA) treatment, as detected by quantitative real-time PCR, Western blotting, and immunohistochemistry. Fluorescence microscopy imaging showed colocalization of cytosolic and plasma membrane NADPH oxidase subunits mainly after PMA treatment, suggesting assembly of the complex after enzyme activation. Cultured EPCs produced superoxide in a NADPH-dependent manner, associating the NADPH oxidase-mediated superoxide production with postimplantation trophoblast physiology. NADPH-oxidase cDNA subunit sequencing showed a high degree of homology between the trophoblast and neutrophil isoforms of the oxidase, emphasizing a putative role for reactive oxygen species production in phagocytic activity and innate immune responses.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Coordenadoria de Aperfeicoamento do Ensino Superior (CAPES)Coordenadoria de Aperfeicoamento do Ensino Superior (CAPES)Conselho Nacional de Pesquisa e Desenvolvimento Tecnologico (CNPq)Conselho Nacional de Pesquisa e Desenvolvimento Tecnologico (CNPq