Avaliação do perfil de metaloproteinases em amostras de tecidos de animais infectados experimentalmente com Trypanosoma cruzi

Abstract

Chagas disease (CD) is caused by the etiological agent Trypanosoma cruzi (T. cruzi) and is characterized by acute and chronic phases. During the acute phase, the parasite targets tissues for which it has tropism and disrupts cytokines and matrix metalloproteinases (MMP), which are the main risk factors for the development of cardiopathies, the most frequent complications in both the acute and chronic phases of the disease. Diagnostic methods to predict the potential for organ damage caused by the parasite are necessary, but currently, only imaging techniques are available to evaluate the damage after disease progression. Therefore, the search for new protein biomarkers associated with CD is one of several strategies for better prognoses. This study aimed to optimize gel-based methods, such as SDS-PAGE and zymography, to evaluate whether T. cruzi infection could alter the MMP profile in organs during the acute phase of CD. To this end, the total protein extract from epimastigote forms of the Y strain of T. cruzi obtained from axenic culture was used, and experimental infection with bloodstream trypomastigote forms was conducted in female mice, which were divided into three groups. Heart, spleen, liver, and blood from animals in all groups were collected to produce total extracts and blood plasma. Optimization allowed the determination of the T. cruzi protein profile, revealing bands with approximate molecular weights of 95, 85, 63, 57, 48-52, 43-45, 40-41, and 29 kDa, which were discussed regarding their possible identification and function in the infection. The results also revealed the protein profiles of cardiac, splenic, hepatic tissues, and plasma in the three analyzed groups. The zymogram of T. cruzi revealed three activity bands with approximate molecular weights of 66 kDa, 55 kDa, and 35 kDa. In the infected animal group, various gelatin-degrading MMPs were observed in the zymogram of tissues and plasma, particularly in the splenic tissue. A significant difference in enzymatic activity was observed in splenic and cardiac tissues, with the alteration in cardiac tissue associated with increased expression of a 93 kDa protease, likely pro-MMP-9, and a 69 kDa protease, likely pro-MMP-2, and in the spleen, an unknown protease of approximately 146 kDa. Therefore, the detection of MMP activity alterations in the analyzed organs and plasma during the acute phase of CD raises new questions about the role of these MMPs in the disease pathogenesis, the impact that synthetic inhibitors of specific MMPs would have on the development of megaly and cardiopathies, and whether such patterns are repeated in the chronic phase of CD, making it possible to consider treatments focused on MMP inhibition and identification of protein alterations characteristic of CD-induced cardiac damage.