Apoptosis is the most prominent process of programmed cell death (for an overview see Fig. 1). Biochemical events lead to characteristic cell changes and death. These changes include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, and chromosomal DNA fragmentation. Furthermore, changes affecting the membrane, nucleus, cytoplasm, and mitochondria occur. Apoptosis involves a complex cascade of reactions regulated by specific proteases called caspases (take a look at previous posts on Caspases as pharmaceutical targets – how to screen for inhibitors?), and results in DNA degradation. Apoptotic processes have been researched in an extensive variety of diseases. Excessive apoptosis causes atrophy, whereas an insufficient amount results in uncontrolled cell proliferation, such as cancer.
Besides apoptosis other types of programed cell death are known, such as autophagy (see How to manipulate and measure Autophagy?), necroptosis, and ferroptosis (look out for an imminent post I’ll be doing about this iron-dependent form of cell death very shortly, as well as tools to differentiate between apoptois, necroptosis, autophagy, and ferroptosis).
In this post, let’s take a look at methods and kits allowing to measure early apoptotic events.