ABSTRACT
INTRODUCTION: The congenital transmission of Trypanosoma cruzi (T. cruzi) is responsible for one-third of new Chagas disease cases each year. During congenital transmission, the parasite breaks down the placental barrier formed by the trophoblast, basal laminae and villous stroma. The observation that only 5% of infected mothers transmit the parasite to the fetus implies that the placenta may impair parasite transmission. The trophoblast undergoes continuous epithelial turnover, which is considered part of innate immunity. Therefore, we propose that T. cruzi induces differentiation in the trophoblast as part of a local antiparasitic mechanism of the placenta. METHODS: We analyzed ß-human chorionic gonadotropin (ß-hCG) and syncytin protein expression in HPCVE and BeWo cells using immunofluorescence and western blotting. Additionally, ß-hCG secretion into the culture medium was measured by ELISA. We assessed the differentiation of trophoblastic cells in BeWo cells using the two-color fusion assay and by determining desmoplakin re-distribution. RESULTS: T. cruzi trypomastigotes induce ß-hCG secretion and protein expression as well as syncytin protein expression in HPCVE and BeWo cells. Additionally, the parasite induces the trophoblast fusion of BeWo cells. DISCUSSION: T. cruzi induces differentiation of the trophoblast, which may contribute to increase the trophoblast turnover. The turnover could be a component of local antiparasitic mechanisms in the human placenta.
Subject(s)
Cell Differentiation , Chagas Disease/pathology , Placenta/parasitology , Trophoblasts/parasitology , Trypanosoma cruzi , Cell Line , Chagas Disease/metabolism , Chorionic Gonadotropin, beta Subunit, Human/metabolism , Female , Gene Products, env/metabolism , Humans , Placenta/metabolism , Placenta/pathology , Pregnancy , Pregnancy Proteins/metabolism , Trophoblasts/metabolism , Trophoblasts/pathologyABSTRACT
BACKGROUND: Chagas' disease is caused by the haemophlagelated protozoan Trypanosoma cruzi (T. cruzi). During congenital transmission the parasite breaks down the placental barrier. In the present study we analyzed the participation of matrix metalloproteases (MMPs) in the extracellular matrix (ECM) remodeling during T. cruzi ex vivo infection of human placental chorionic villi explants. METHODS: Chorionic villi from healthy woman placentas were incubated in the presence or absence of 105 or 106 T. cruzi trypomastigotes (Y strain) with or without the MMPs inhibitor doxycycline. Effective infection was tested measuring parasite DNA by real time PCR (qPCR). MMP-2 and MMP-9 expression were determined by western blotting and immunohistochemistry and their activities were measured by zymography. The effect of MMPs on ECM structure was analyzed histochemically. RESULTS: T. cruzi induces the expression and activity of MMP-2 and MMP-9 in chorionic villi. Inhibition of the MMPs prevents the tissue damage induced by T. cruzi and partially decreases the ex vivo infection of the chorionic villi. CONCLUSION: MMPs are partially responsible for the ECM changes observed in human chorionic villi during T. cruzi infection and participate in tissue invasion. On the other hand, MMPs may be part of a local placental antiparasitic mechanism.
Subject(s)
Chagas Disease/immunology , Chorionic Villi/enzymology , Disease Resistance , Enzyme Induction , Matrix Metalloproteinase 2/biosynthesis , Matrix Metalloproteinase 9/biosynthesis , Trypanosoma cruzi/immunology , Blotting, Western , Chagas Disease/pathology , Chagas Disease/prevention & control , Chagas Disease/transmission , Chorionic Villi/immunology , Chorionic Villi/parasitology , Chorionic Villi/pathology , DNA, Protozoan/metabolism , Doxycycline/pharmacology , Extracellular Matrix/immunology , Extracellular Matrix/metabolism , Extracellular Matrix/parasitology , Extracellular Matrix/pathology , Extracellular Matrix Proteins/metabolism , Female , Humans , Immunohistochemistry , Matrix Metalloproteinase 2/chemistry , Matrix Metalloproteinase 2/metabolism , Matrix Metalloproteinase 9/chemistry , Matrix Metalloproteinase 9/metabolism , Pregnancy , Protease Inhibitors/pharmacology , Proteolysis/drug effects , Tissue Culture Techniques , Trypanocidal Agents/pharmacology , Trypanosoma cruzi/drug effects , Trypanosoma cruzi/isolation & purification , Trypanosoma cruzi/pathogenicityABSTRACT
Congenital Chagas' disease, endemic in Latin America and also present with lower frequency in other countries, is associated with premature labor, miscarriage, and placentitis. The mechanism of tissue invasion and infection of human placenta by the parasite Trypanosoma cruzi (T. cruzi) remains unclear. In order to explore some morphological aspects of this infection in the placenta, we incubated chorionic villous explants from normal human placentae ex vivo with the parasite and studied the resulting effects by immunohistochemical and histochemical methods. Infection of the chorionic villi with the parasite was confirmed by immunofluoresence and PCR. T. cruzi induces syncytiotrophoblast destruction and detachment, selective disorganization of basal lamina and disorganization of collagen I in the connective tissue of villous stroma. These effects are a function of the number of parasites used for the infection. Our results suggest a participation of the proteolytic activity of the parasite on the placental basal lamina and connective tissue in the mechanism of infection of the fetus by T. cruzi.