Simvastatin improves cardiac function through Notch 1 activation in BALB/c mice with Chronic Chagas Cardiomyopathy

Abstract

Chagas disease, caused by the protozoan Trypanosome cruzi, endemic in Latin America but distributed worldwide because of migration. Without appropriate treatment, the disease progresses from an acute asymptomatic phase to a chronic, progressive inflammatory cardiomyopathy causing heart failure and death. Despite specific trypanocidal therapy, heart damage progression cannot be stopped or reversed. Statins, as part of their pleiotropic actions, can modulate chagasic myocarditis by inducing the production of 15-epi-lipoxin A(4) (15-epi-LXA(4)), a proresolution lipid mediator in inflammation. Furthermore, several reports suggest that simvastatin activates the Notch pathway after stroke in cerebral endothelial cells, enhancing blood flow by promoting angiogenesis. Thus, statins are an attractive therapeutic strategy for modulating the Notch pathway to reverse the chronic heart damage induced by T. cruzi. BALB/c mice chronically infected with T. cruzi were treated with 1 mg/kg/day simvastatin or 25 mu g/kg/day 15-epi-LXA 4 for 20 days. During the treatment period, cardiac function was evaluated by echocardiography. At 80 days postinfection, the heart tissues were assessed for Notch 1 activity. T. cruzi infection activated the Notch 1 pathway, and simvastatin (but not 15-epi-lipoxin A(4)) produced a further increase in that activity, correlating with improvement in the ejection fraction and histopathologic findings typical of T. cruzi infection, including improvements in inflammation and fibrosis. Moreover, simvastatin increased the number of isolectin B4-positive cells, suggesting active angiogenesis in the chronically infected hearts without alteration of the parasitic load. Simvastatin, probably acting through the Notch 1 pathway, decreases inflammation, improving cardiac function in mice chronically infected with T. cruzi.