Trypanosoma cruzi induces trophoblast differentiation: a potential local antiparasitic mechanism of the human placenta?

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.

Role of matrix metalloproteinases 2 and 9 in ex vivo Trypanosoma cruzi infection of human placental chorionic villi.

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.

Trypanosoma cruzi induces apoptosis in ex vivo infected human chorionic villi.

Chagas' disease, produced by the haemoflagellated protozoan Trypanosoma cruzi (T. cruzi), is one of the most frequent endemic diseases in Latin America. In spite that in the past few years T. cruzi congenital transmission has become of epidemiological importance, studies about this mechanism of infection are scarce. The placental tissue undergoes apoptosis throughout gestation, as part of its normal turnover. On the other hand, it is known that T. cruzi induces, delays or inhibits apoptosis in other mammalian tissues. In order to determine the effect of parasite invasion on normal apoptosis in the placenta, explants of human chorionic villi were incubated with 105 trypomastigotes for 24 h. Effective infection was tested by visualizing T. cruzi antigens in histological preparations and by PCR. Upon infection, apoptotic cell death was determined by light and transmission electron microscopy, TUNEL analysis, measurement of caspase-3 like activity and immunohistochemical detection of caspase 3 cleaved cytokeratin 18. Our results clearly show that T. cruzi induces apoptosis in the chorionic villi and suggest that this is one of mechanisms used by the parasite to insure infection and invasion of human placenta and fetus.

Trypanosoma cruzi induces tissue disorganization and destruction of chorionic villi in an ex vivo infection model of human placenta.

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.

[Surgical treatment of relapsing keloid of the pinna by fillet flap]. / Tratamiento quirúrgico del queloide recidivante de pabellón auricular mediante <>.

BACKGROUND AND OBJECTIVES: Keloid scars occur when, compared to normal healing, there is excessive formation of collagen after skin wounds or burns. Different treatments have been tried, though no particular one has been shown to be superior. The objective of this study was to assess the usefulness of the surgical technique originally described as keloid fillet flap in the management of relapsing keloids of the pinna. MATERIAL AND METHODS: The study included 10 patients (8 men, 9 white and 1 black) with a keloid on the retroauricular region or earlobe of more than 1 year duration, who had undergone previous treatment (surgery and topical or injected corticosteroids) without a good outcome or with relapse, and who had not received any treatment in the previous 6 months. RESULTS: Five patients were treated with a fillet flap procedure only, while the other 5, in addition to the procedure, also applied 5% imiquimod cream 5 times a week for 1 to 3 months. In 4 patients, no relapse was observed after the intervention. Two patients had partial flap necrosis, with subsequent partial relapse in one of these. Eighty percent reported the outcome of the procedure as good or excellent. CONCLUSION: We achieved a response rate of 40% in the treatment of relapsing keloid of the pinna by a fillet flap procedure. This may be an alternative within the therapeutic arsenal for the treatment of relapsing keloid of the pinna, given that it does not require extensive resources and the skills needed to perform the procedure can be quickly acquired.

Tratamiento quirúrgico del queloide recidivante de pabellón auricular mediante «colgajo en filete» / Surgical treatment of relapsing keloid of the pinna by fillet flap

Introducción y objetivos: El queloide se caracteriza por la formación excesiva de colágeno respecto a la cicatrización normal y puede aparecer de forma secundaria tras una herida o quemadura cutánea. Para su corrección se han ensayado diversos tratamientos, sin que ninguno haya demostrado su superioridad. El objetivo de este estudio es valorar la utilidad de la técnica quirúrgica originalmente descrita como keloid fillet flap (colgajo «en filete») para el tratamiento de queloides auriculares recidivantes. Material y métodos: Se seleccionaron diez pacientes (ocho varones, nueve de raza blanca, uno de raza negra) con queloide retroauricular o de lóbulo recidivante de más de un año de evolución, que habían recibido tratamiento previo (cirugía y corticoides tópicos o en infiltración) sin resultado o con recidiva, y que no habían recibido ningún tipo de tratamiento en los últimos seis meses. Resultados: Cinco pacientes fueron tratados quirúrgicamente solo con colgajo «en filete» y otros cinco con colgajo e imiquimod crema al 5% cinco veces por semana durante uno a tres meses. En cuatro pacientes no se apreció recidiva tras la intervención. Dos pacientes presentaron necrosis parcial del colgajo, uno de los cuales desarrolló recidiva parcial de la lesión. El 80% calificó el resultado de la intervención como bueno o excelente. Conclusiones: Hemos conseguido un 40% de respuesta en el tratamiento del queloide auricular recidivante mediante la realización de colgajo «en filete». Este puede representar una alternativa dentro del arsenal terapéutico disponible para el tratamiento del queloide auricular recidivante, dado que no necesita de grandes medios y puede realizarse después de un entrenamiento mínimo (AU)

Background and objectives: Keloid scars occur when, compared to normal healing, there is excessive formation of collagen after skin wounds or burns. Different treatments have been tried, though no particular one has been shown to be superior. The objective of this study was to assess the usefulness of the surgical technique originally described as keloid fillet flap in the management of relapsing keloids of the pinna. Material and methods: The study included 10 patients (8 men, 9 white and 1 black) with a keloid on the retroauricular region or earlobe of more than 1 year duration, who had undergone previous treatment (surgery and topical or injected corticosteroids) without a good outcome or with relapse, and who had not received any treatment in the previous 6 months. Results: Five patients were treated with a fillet flap procedure only, while the other 5, in addition to the procedure, also applied 5% imiquimod cream 5 times a week for 1 to 3 months. In 4 patients, no relapse was observed after the intervention. Two patients had partial flap necrosis, with subsequent partial relapse in one of these. Eighty percent reported the outcome of the procedure as good or excellent. Conclusion: We achieved a response rate of 40% in the treatment of relapsing keloid of the pinna by a fillet flap procedure. This may be an alternative within the therapeutic arsenal for the treatment of relapsing keloid of the pinna, given that it does not require extensive resources and the skills needed to perform the procedure can be quickly acquired (AU)

Paraneoplastic pemphigus associated with Castleman's disease: usefulness of the laboratory of autoimmunity in the diagnosis of this disease.

We report on a case of paraneoplastic pemphigus associated with Castleman's disease. Clinical pathologic features were not conclusive. Diagnosis was established thanks to the detection of seric autoantibodies directed against intercellular substance by indirect immunofluorescence on monkey esophagus. The positive result of this test prompted us to reevaluate the patient and to detect the occult neoplasia. The demonstration of autoantibodies against plakins is the key marker of this disease but depends on tests that may not be readily available in many places like immunoprecipitation, immunoblotting, or indirect immunofluorescence over rat bladder. In this setting, tests like indirect immunofluorescence over monkey esophagus, although unspecific, may aid in reaching the appropriate diagnosis. This case illustrates the importance of the laboratory of autoimmunity in the diagnosis of this type of pemphigus.