Apoptotic Cells and Myocardial Infarction

Myocardial infarction (MI) followed by cardiac remodeling is a major cause of congestive heart failure and death. Of clinical relevance are reports that demonstrated that infusion of apoptotic cells leads to allogeneic hematopoietic cell engraftment in transplantation models and to a delay of lethal acute graft-versus-host disease by initiating immunesuppressive mechanisms. Based on these reports, we hypothesized that apoptotic cells can reduce inflammatory reactions after MI. To corroborate this hypothesis, irradiated apoptotic cells were infused intravenously in an experimental rat model of MI. Rats that were infused with apoptotic cells showed enhanced homing of macrophages and endothelial progenitor cells (EPC) as compared to controls. Planimetric analysis showed a significant reduction of infarction size and improvement of post MI remodeling with less signs of dilation. Echocardiography revealed that cardiac function was almost preserved in treated animals compared to untreated controls. These data indicate that apoptotic cell suspensions circumvent inflammation, cause homing of regenerative EPC and preserve cardiac function.