Figure 1.

Contrasting phagocytic clearance in advanced atherosclerosis and post myocardial infarction. Advanced atherosclerosis is characterized by recruitment of Ly-6C-HI monocytes that differentiate into macrophages. Macrophage apoptotic cell receptors, such as MerTK and LRP promote efferocytosis. However, in the inflammatory setting of mature atheromata, efferocytosis becomes defective (see Tabas, 2010) leading to secondary necrosis, necrotic core expansion, and susceptibility to myocardial infarction (MI). Post MI, both Ly-6C-HI and LO monocytes marginate into myocardial tissue to differentiate into macrophages and promote clearance of apoptotic and necrotic cells (see Nahrendorf et al., 2007). These acute events can affect later cardiac remodeling and inflammation that may lead to heart failure.