Elaboration by mammalian mesenchymal cells infected with Trypanosoma cruzi of a fibroblast-stimulating factor that may contribute to chagasic cardiomyopathy.
Myocardial fibrosis can occur as a complication of chronic infection of the heart with Trypanosoma cruzi (Chagas' disease) and can lead to serious disability. To assess whether there might be a direct relationship between intracellular parasitization and subsequent tissue fibrosis in this disease, we tested serum-free conditioned media from cultures of fibroblasts, vascular smooth-muscle cells, and myocardial cells for fibroblast-stimulating activity. Conditioned media from all infected cultures, but not from uninfected cultures, stimulated fibroblast [3H]thymidine incorporation, DNA and protein synthesis, and cell proliferation. Fibroblast-stimulating activity was also detected in extracts of amastigotes but not of trypomastigotes or epimastigotes. We conclude that parasitization of mesenchymal cells, including myocardial cells, results in elaboration of a fibroblast-stimulating factor(s), perhaps of parasite origin. We postulate that this factor may play a role in initiation of myocardial fibrosis in Chagas' disease.
D000818:Animals; D002598:Chagas Cardiomyopathy / Q000209:etiology*; D014355:Chagas Disease / Q000503:physiopathology*; D003470:Culture Media; D005347:Fibroblasts / Q000166:cytology*; D006133:Growth Substances / Q000096:biosynthesis*; D006321:Heart / Q000469:parasitology; D006801:Humans; D066298:In Vitro Techniques; D009130:Muscle, Smooth; D009206:Myocardium / Q000166:cytology; D014349:Trypanosoma cruzi
D003470:Culture Media; D006133:Growth Substances