title: Reduced activity of matrix metalloproteinase-9 in trypanosoma cruzi-infected mouse embryo hepatocyte cell.
abstract: In this work, we are reporting differences in the proteolytic profile of Trypanosoma cruzi-infected and non-infected primary cultures of mouse embryo hepatocyte cells. In gelatin-SDS-PAGE, ours results showed the presence of a 100kDa metalloproteinase in the supernatant and in the cells of both systems and an 85kDa extracellular metalloproteinase found only in the non-infected hepatocyte cultures. An enzymatic assay using gelatin as substrate showed a decrease of 74 and 70% in metalloproteinase activity in the culture supernatant and in the cell hepatocyte system infected with T. cruzi, respectively. Western blotting analysis using anti-matrix metalloproteinase-9 (MMP-9) antibody recognized the 100 and 85kDa protein bands, indicating that hepatocyte metalloproteinases correspond to the latent and active forms of the gelatinase MMP-9, respectively. The localization of MMP-9 was established by immunocytochemistry analysis in the cytoplasm of the non-infected and infected hepatocyte cells. In normal and infected hepatocyte cells, cysteine-proteinases migrating in gelatin-SDS-PAGE at 60kDa were detected and should correspond to lysosomal cysteine-proteinases of T. cruzi (cruzipain) and hepatocytes. In T. cruzi-infected hepatocytes an increase of approximately 50% in this enzymatic activity was observed, possibly due to parasite's cruzipain.
authors.affiliation: Department of General Microbiology, Institute of Microbiology Prof Paulo de Góes, Federal University of Rio de Janeiro, CCS, Bl I, 21941-590, RJ, Rio de Janeiro, Brazil
authors.forename: Ana Cristina
authors.initials: AC
authors.lastname: Nogueira de Melo
authors.forename: Maria Nazareth L.
authors.initials: MN
authors.lastname: Meirelles
authors.forename: Renato
authors.initials: R
authors.lastname: Porrozzi
authors.forename: Juliana Dias
authors.initials: JD
authors.lastname: Costa
authors.forename: Marta Helena
authors.initials: MH
authors.lastname: Branquinha
authors.forename: Alane Beatriz
authors.initials: AB
authors.lastname: Vermelho