Myenteric plexus is differentially affected by infection with distinct Trypanosoma cruzi strains in Beagle dogs

Nívia Carolina Nogueira-Paiva,Kátia Da Silva Fonseca,Paulo Marcos Da Matta Guedes,Lívia Figueiredo Diniz,Maria Terezinha Bahia,Paula Melo De Abreu Vieira,Cláudia Martins Carneiro,Vanja Maria Veloso,Washington Luiz Tafuri,Sandra Aparecida Lima De Moura,Ivo Santana Caldas

doi:10.1590/0074-0276130216

Nívia Carolina Nogueira-Paiva, Kátia Da Silva Fonseca + Show 9 more

Open Access

https://doi.org/10.1590/0074-0276130216

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Abstract

Chagasic megaoesophagus and megacolon are characterised by motor abnormalities related to enteric nervous system lesions and their development seems to be related to geographic distribution of distinct Trypanosoma cruzi subpopulations. Beagle dogs were infected with Y or Berenice-78 (Be-78) T. cruzi strains and necropsied during the acute or chronic phase of experimental disease for post mortem histopathological evaluation of the oesophagus and colon. Both strains infected the oesophagus and colon and caused an inflammatory response during the acute phase. In the chronic phase, inflammatory process was observed exclusively in the Be-78 infected animals, possibly due to a parasitism persistent only in this group. Myenteric denervation occurred during the acute phase of infection for both strains, but persisted chronically only in Be-78 infected animals. Glial cell involvement occurred earlier in animals infected with the Y strain, while animals infected with the Be-78 strain showed reduced glial fibrillary acidic protein immunoreactive area of enteric glial cells in the chronic phase. These results suggest that although both strains cause lesions in the digestive tract, the Y strain is associated with early control of the lesion, while the Be-78 strain results in progressive gut lesions in this model.

Highlights

Focal inflammatory infiltrates can be observed in the asymptomatic form regardless of parasite presence
Given the scarcity of experimental models to study digestive tract changes in Chagas disease (ChD) and similarities in disease progression in a canine model (Canis familiaris), as well as the potential role of enteric nervous system (ENS) components in the development of the digestive form of ChD, this study evaluated the profile of changes that occurred in the oesophagus and colon of Beagle dogs after infection with two morphologically distinct T. cruzi subpopulations belonging to the discrete typing unit (DTU) TcII
An inflammatory process was observed in both organs of animals infected with Y and Be-78 T. cruzi strains compared to the NI group

Summary

Introduction

Focal inflammatory infiltrates can be observed in the asymptomatic form regardless of parasite presence. Studies in cell culture have confirmed the existence of two types of EGCs, EGC- glial fibrillary acidic protein (GFAP)+ and the EGC-GFAP- They have shown that increased expression of GFAP, interpreted as a response to trauma, is associated with the pro-inflammatory cytokines tumour necrosis factor-α and interleukin-1β (Von Boyen et al 2004), with expression possibly related to increased cohesion between glial cells (Buniatian et al 2002). The increase in glial cells was related to lower inflammatory infiltrates and to lower levels of neuronal damage, less dilatation of the organ and the absence of megaoesophagus pathophysiological manifestations (Nascimento et al 2010) In this sense, EGC expansion, it cannot prevent the parasite invasion (da Silveira et al 2005), may help to control the inflammatory process by preventing injuries associated with denervation, swelling and organ function loss (Nascimento et al 2010)

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