Cellular Aging: Cell Death

Apoptosis research was quite extensive at the end of the twentieth century, and it focused on several goals:

• • Blockage of apoptosis by inhibition of caspases. Several inhibitors of caspases are now known. Although inhibition of caspase may not protect a cell limited for other reasons, it is likely to produce a "zombie" cell, which continues to exist but is incapable of performing a specific function such as conducting an impulse or contracting, and in acute situations such as a heart attack it may buy time.
• • Maintenance of challenged systems. For instance, approaches used in addressing the loss of cells in AIDS include supportive therapies and administration of growth factors that are known to suppress apoptosis.
• • Targeting of apoptosis. Attempts have been made to control apoptosis by attacking the machinery of apoptosis (such as caspases, particularly in acute emergencies such as stroke), but since most cells possess the machinery for apoptosis, regulation of apoptosis is more likely to focus on identifying the cells to be controlled and arranging a mechanism to specifically target these cells, using inhibitors or ligands to achieve the up- or down-regulation of the apoptosis machinery.