Fas-Induced Necrosis.

Fas/CD95 is an important regulator of cell death in development and homeostasis of the immune system. Apoptosis is the most frequently observed type of cell death induced by Fas. It is characterized by cell shrinkage and nuclear fragmentation, while organelles and the plasma membrane retain their integrity for a prolonged period. Intensive studies of apoptotic cell death led to the discovery of the involvement of caspases. The first reports on necrotic caspase-independent cell death induced by Fas appeared in the late nineties. Necrotic cell death is characterized by minor nuclear changes and swelling of the cell, resulting in plasma and organelle membrane rupture. The current review focuses on Fas-initiated signaling events that allow a switch between apoptotic and necrotic cell death and on the mitochondrial processes that regulate an apoptotic or necrotic outcome. Finally, we describe events that are crucial for the execution of the necrotic cell death process. [ABSTRACT FROM AUTHOR]