Mechanisms involved in mediating CD47-induced cell death. Ligation of CD47 by mAbs or TSP 1 induces apoptosis, which involves the activation of heterotrimeric Gi proteins, reduction in cAMP, and exposure of phosphatidylserine in the outer leaflet of the plasma membrane. It also induces the expression of the proapoptotic Bcl-2 family member BNIP3, its association with CD47, and subsequent translocation of BNIP3 to mitochondria. CD47-induced apoptosis may also involve ROS and F-actin.