Rapamycin Treatment Reduces Acute Myocarditis Induced by Trypanosoma cruzi Infection.

Chagas disease affects millions of people mainly in Latin America and is a protozoan illness caused by the parasite Trypanosoma cruzi. Chagasic cardiomyopathy is the leading cause of mortality of infected patients, due to compromised electrical and mechanical cardiac function induced by tissue remodeling, especially fibrosis, and lymphocytic infiltration. Some cellular biochemical pathways can be protective to the heart, and we tested if the in vivo activation of the autophagic machinery by rapamycin could reduce parasite-induced myocarditis. Regarding the expression of LC3, an autophagy marker, we observed its upregulation in the cardiac tissue of infected untreated mice. However, after rapamycin treatment, an autophagy inducer, infected mice showed reduced electrical cardiac dysfunctions, myocarditis, cardiac damage, and reduced production of pro-inflammatory cytokines by the heart. On the other hand, the parasite's life cycle was not affected, and we observed no modulations in cardiac tissue or blood parasitemia. Our data indicate that, at least partially, autophagy induction controls inflammation in the heart¸ illustrating the complexity of the pathways that concur to the development of the infection.