RESUMO
This study was conducted to investigate annexin A1 (ANXA1) functions in human placental explants infected with Toxoplasma gondii (T. gondii). We examined the first and third trimester placental explants infected with T. gondii (nâ¯=â¯7 placentas/group) to identify the number and location of parasites, ANXA1 protein, potential involvement of formyl peptide receptors (FPR1 and FPR2), and COX-2 expressions by immunohistochemistry. Treatments with Ac2-26 mimetic peptide of ANXA1 were performed to verify the parasitism rate (ß-galactosidase assay), prostaglandin E2 levels (ELISA assay), and ANXA1, FPR1 and COX-2 expression in third trimester placentas. Placental explants of third trimester expressed less ANXA1 and were more permissive to T. gondii infection than first trimester placentas that expressed more ANXA1. Ac2-26 treatment increases endogenous ANXA1 and decreases parasitism rate, COX-2, and prostaglandin E2 levels. Altogether, these data provide further insight into the anti-parasitic and anti-inflammatory effects of ANXA1 in placentas infected with T. gondii.
Assuntos
Anexina A1/farmacologia , Antiparasitários/farmacologia , Placenta/efeitos dos fármacos , Toxoplasma/efeitos dos fármacos , Toxoplasma/patogenicidade , Toxoplasmose/tratamento farmacológico , Anti-Inflamatórios/farmacologia , Estudos Transversais , Ciclo-Oxigenase 2/metabolismo , Dinoprostona/metabolismo , Feminino , Humanos , Inflamação/tratamento farmacológico , Peptídeos/farmacologia , Placenta/patologia , Placenta/fisiopatologia , Gravidez , Terceiro Trimestre da Gravidez , Receptores de Formil Peptídeo/metabolismo , Receptores de Lipoxinas/metabolismo , Toxoplasmose/patologia , beta-Galactosidase/análiseRESUMO
The phosphatidylinositol 3-kinase (PI3K)/Akt pathway has an anti-apoptotic effect through several downstream targets, which includes activation of the transformed mouse 3T3 cell double-minute 2 (Mdm2) protein, its translocation to the nucleus and degradation of the tumor suppressor p53. We show that Mif, the Macrophage Migration Inhibitory Factor, an important cytokine at the maternal fetal interface in several species, triggers phosphorylation of Mdm2 protein in a PI3K/Akt-dependent manner, thereby preventing apoptosis in cultured mouse decidual cells. Inhibition of Akt and PI3K suppresses the pathway. Mif treatment also changes the nuclear translocation of p53 and interferes with the apoptotic fate of these cells when challenged with reactive oxygen species. In conclusion, an important mechanism has been found underlying decidual cell survival through Akt signaling pathway activated by Mif, suggesting a role for this cytokine in decidual homeostasis and in the integrity of the maternal-fetal barrier that is essential for successful gestation.
Assuntos
Decídua/citologia , Fatores Inibidores da Migração de Macrófagos/farmacologia , Fosfatidilinositol 3-Quinase/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Células 3T3 , Animais , Apoptose , Sobrevivência Celular , Feminino , Humanos , Troca Materno-Fetal/fisiologia , Camundongos , Fosforilação/efeitos dos fármacos , Gravidez , Transdução de Sinais/fisiologiaRESUMO
Because macrophage migration inhibitory factor (MIF) is a key cytokine in pregnancy and has a role in inflammatory response and pathogen defense, the objective of the present study was to investigate the effects of MIF in first- and third-trimester human placental explants infected with Toxoplasma gondii. Explants were treated with recombinant MIF, IL-12, interferon-γ, transforming growth factor-ß1, or IL-10, followed by infection with T. gondii RH strain tachyzoites. Supernatants of cultured explants were assessed for MIF production. Explants were processed for morphologic analysis, immunohistochemistry, and real-time PCR analysis. Comparison of infected and stimulated explants versus noninfected control explants demonstrated a significant increase in MIF release in first-trimester but not third-trimester explants. Tissue parasitism was higher in third- than in first-trimester explants. Moreover, T. gondii DNA content was lower in first-trimester explants treated with MIF compared with untreated explants. However, in third-trimester explants, MIF stimulus decreased T. gondii DNA content only at the highest concentration of the cytokine. In addition, high expression of MIF receptor was observed in first-trimester placental explants, whereas MIF receptor expression was low in third-trimester explants. In conclusion, MIF was up-regulated and demonstrated to be important for control of T. gondii infection in first-trimester explants, whereas lack of MIF up-regulation in third-trimester placentas may be involved in higher susceptibility to infection at this gestational age.
Assuntos
Idade Gestacional , Oxirredutases Intramoleculares/metabolismo , Fatores Inibidores da Migração de Macrófagos/metabolismo , Placenta/metabolismo , Placenta/parasitologia , Toxoplasma/fisiologia , Toxoplasmose/parasitologia , Antígenos de Diferenciação de Linfócitos B/genética , Antígenos de Diferenciação de Linfócitos B/metabolismo , Feminino , Regulação da Expressão Gênica , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/metabolismo , Humanos , Oxirredutases Intramoleculares/biossíntese , Oxirredutases Intramoleculares/farmacologia , Fatores Inibidores da Migração de Macrófagos/biossíntese , Fatores Inibidores da Migração de Macrófagos/farmacologia , Modelos Biológicos , Nitritos/metabolismo , Placenta/efeitos dos fármacos , Placenta/patologia , Gravidez , Primeiro Trimestre da Gravidez/efeitos dos fármacos , Terceiro Trimestre da Gravidez/efeitos dos fármacos , Toxoplasma/citologia , Toxoplasma/efeitos dos fármacos , Toxoplasmose/patologia , Toxoplasmose/prevenção & controleRESUMO
BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.