Avaliação de neurotrofinas no processo de regeneração neuronal do sistema nervoso entérico de pacientes chagásicos portadores de megacólon

Abstract

Patients with the digestive form of Chagas' disease exhibit a number of symptoms related to obstruction of the organ. Histological analysis of affected organs have demonstrated inflammatory lesions of the enteric nervous system (ENS), associated with a large reduction in the number of neurons caused, mainly, by inflammatory process. However, previous studies presented that some substances, like neurotrophins, may restrict neuronal destruction levels. The objective of this study is to characterize the neurotrophins expression in tissues from chagasic patients with chagasic megacolon and verify its involvement in megacolon development. For this, we used samples from chagasic patients with megacolon (n=8) and non-infected individuals (n=8) that, after preparation, were submitted to confocal fluorescence immunohistochemistry. To identify the sources and expression level of neurotrophins (NGF, GDNF and NT3), we performed a co-localization with Peripherin (neuronal marker) and S-100 (glial cell marker). Our results presented that, in the colon, the glial cells are the main sources of neurotrophins in all analyzed groups. Besides, chagasic patients with megacolon presented high expression of all investigated neurotrophins when compared with non-infected individuals. Our data point that neurotrophins might perform a protective role in the enteric nervous system and that prevent the megacolon installation. By the other side, chagasic patients that do not express an adequate level of neurotrophins may progress to megacolon form. We believe that this data can suggest new treatment protocols, like drugs administration qualified to elevate neurotrophins levels, what could prevent the megacolon installation and maintain the normal function of the gastrointestinal tract.