Apoptosis is a process of programmed cell death that participates in many physiological processes such as organ development, immune cell education, and normal cell turnover. However, under some conditions, apoptosis can be detrimental. For example, apoptosis of neurons is associated with neurodegenerative diseases and apoptosis of CD4+ T cells is associated with HIV-1-related pathology.
Apoptosis can be induced by both intracellular and extracellular signals which activate a cascade of proteins such as pro-apoptotic Bcl-2 family members and caspases. Effector caspases execute cell death by proteolytically cleaving proteins that are necessary for cell function. Cells undergoing apoptosis show phenotypic characteristics such as cell blebbing, shrinkage, DNA fragmentation, and Chromatin condensation.
Small molecules can play an important role in defining factors that induce apoptosis as well as differentiating the specific pathway that leads to cell death. For example, apoptosis mediated by Caspase-9 can be assessed using a fluorogenic Caspase-9 substrate (Catalog # 1575) that generates a fluorescent signal upon proteolytic cleavage. The involvement of other caspases as well as other proteins that mediate apoptosis can also be manipulated by small molecule agonists, antagonists, and substrates.