Estudo da actividade angiogénica na nurse cell de trichinella spiralis no decurso da triquinelose em modelo roedor

A triquinelose é uma zoonose parasitária que é transmitida aos humanos e animais, através da ingestão de carne crua ou insuficientemente cozinhada, que contenha larvas infectantes de Trichinella spp., sendo actualmente considerada uma doença emergente e/ou re-emergente. O sucesso do parasitismo do nemátode Trichinella spiralis está intimamente ligado com o processo de angiogénese, ou seja, a formação de novos vasos a partir de vasos pré-existentes. Com o objectivo de estudar a actividade angiogénica na nurse cell de T. spiralis, realizaram-se técnicas imunohistoquímicas e imunofluorescentes para o factor de crescimento endotelial vascular (VEGF), molécula-1 de adesão celular endotelial a plaquetas (PECAM-1) e actina músculo liso (AML), em tecido muscular de Rattus rattus infectado com T. spiralis. Através destas técnicas observou-se marcação intensa no infiltrado inflamatório adjacente à nurse cell e também na larva. Já o citoplasma da nurse cell apresentou uma marcação moderada. Este padrão de marcação manteve-se desde os 45 até aos 120 dias após a infecção. A avaliação da densidade vascular (PECAM-1) e da densidade da expressão de células positivas para AML permitiu estabelecer uma correlação positiva entre o aumento da densidade vascular e o número de dias de infecção. Adicionalmente estabeleceu-se uma correlação negativa entre o aumento da densidade de células que expressam AML e o número de dias de infecção. Os resultados indicam uma produção constante de VEGF pela larva, pelo citoplasma da nurse cell e pelo hospedeiro (infiltrado inflamatório), durante todo período de infecção, levando à formação de uma rede vascular crescente (com um aumento médio de 79% face ao controlo), acompanhada de células murais que promovem a sua estabilização (com um aumento médio de 50% face ao controlo) com particular incidência no primeiro período estudado (45 a 55 dias).Trichinellosis is a parasitic zoonosis, transmitted to humans and animals through the ingestion of raw or undercooked meat, containing infective larvae of Trichinella spp. This disease is currently considered as emerging and / or re-emerging. Nematode Trichinella spiralis success as a parasite is strongly related to the angiogenesis process, that is, the formation of new vessels from pre-existing ones. In order to study the angiogenic activity in T. spiralis nurse cell, immunohistochemistry and immunofluorescence for vascular endothelial grow factor (VEGF), platelet/endothelial cell adhesion molecule-1 (PECAM-1), and α- smooth muscle actin (SMAα) was performed on Rattus rattus muscular tissue infected with T. spiralis. Intense immunostaining of VEGF was observed in the surrounding inflammatory cell infiltrate and larva. Moderate immunostaining was noted in the developing nurse cell cytoplasm. This pattern persisted from day 45 to day 120 after initial infection. Vessel density (PECAM-1) and positive cells for SMAα density were evaluated. A positive correlation was found between vascular density and the number of days after the initial infection. A negative correlation was established between the density of cells expressing AML and the number of days. These results show that there is a constant production of VEGF by the larva, nurse cell cytoplasm and the host (inflammatory infiltrate) during the full period of infection, which results in the formation and enlargement of the vascular network (with an average increase of 79% comparing with the control), accompanied by the maturation and stabilization of the vessels (with an average increase of 50% comparing with the control), mainly in the first observed period (45-55 days). Vessel density (PECAM-1) and positive cells for SMAα density were evaluated. A positive correlation was found between vascular density and the number of days after the initial infection. A negative correlation was established between the density of cells expressing AML and the number of days. These results show that there is a constant production of VEGF by the larva, nurse cell cytoplasm and the host (inflammatory infiltrate) during the full period of infection, which results in the formation and enlargement of the vascular network (with an average increase of 79% comparing with the control), accompanied by the maturation and stabilization of the vessels (with an average increase of 50% comparing with the control), mainly in the first observed period (45-55 days). Vessel density (PECAM-1) and positive cells for SMAα density were evaluated. A positive correlation was found between vascular density and the number of days after the initial infection. A negative correlation was established between the density of cells expressing AML and the number of days. These results show that there is a constant production of VEGF by the larva, nurse cell cytoplasm and the host (inflammatory infiltrate) during the full period of infection, which results in the formation and enlargement of the vascular network (with an average increase of 79% comparing with the control), accompanied by the maturation and stabilization of the vessels (with an average increase of 50% comparing with the control), mainly in the first observed period (45-55 days). Vessel density (PECAM-1) and positive cells for SMAα density were evaluated. A positive correlation was found between vascular density and the number of days after the initial infection. A negative correlation was established between the density of cells expressing AML and the number of days. These results show that there is a constant production of VEGF by the larva, nurse cell cytoplasm and the host (inflammatory infiltrate) during the full period of infection, which results in the formation and enlargement of the vascular network (with an average increase of 79% comparing with the control), accompanied by the maturation and stabilization of the vessels (with an average increase of 50% comparing with the control), mainly in the first observed period (45-55 days)