The biology of caspases in central nervous system trauma

Programmed cell death (PCD) is a naturally occurring event in the developing organism, whereby damaged, mislocated, or superfluous cells are discretely and efficiently removed. All of our cells contain the machinery required for their own demise, which occurs through a process of apoptosis and must be highly regulated. Recent research has shown that the apoptotic machinery in many cell types is activated in the central nervous system (CNS) following a variety of insults. Once apoptosis is initiated, an intricate process ensures activation of a family of cysteine proteases called caspases, which are responsible for many of the morphological and biochemical features of apoptosis. Currently, 14 caspases have been identified. In this chapter, we begin with a brief discussion of the structure and function of the caspases. Next, several pathways of apoptotic cell death will be presented, focusing on caspase participation. The chapter concludes with a discussion of data regarding caspase activation following CNS insults, as well as potential therapeutic strategies that target various events in the apoptotic process.