Modulating or inhibiting Caspase activities

In a previous post, I discussed Caspases as pharmaceutical targets – how to screen for inhibitors?

Today I would like to concentrate on Caspase inhibitors/modulators, which allow for in-depth characterisation of your enzyme of interest and which can serve as reference compounds in caspase inhibitor screenings. A short recap: Caspases (Cysteine-dependent aspartate-directed proteases) belong to the family of cysteine proteases and are involved in networks controlling cell death (apoptosis and necrosis) and inflammation. Amongst the 12 known human caspases, 5 have been described as playing a crucial role in  apoptosis (Caspase-3, -6, -7, -8, and -9), 4 have been linked to processes in inflammation (Caspase-1, -4, -5, and -12), and 3 (Caspase-2, -10, and -14) could not yet be exactly classified concerning their functions. [Read more…]

How to measure early apoptotic events?

Apoptosis and cellular apoptotic events. Source: tebu-bio

Fig. 1: Process of Apoptosis

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. [Read more…]

Caspases as pharmaceutical targets – screening for inhibitors?

Caspases (cysteine-dependent aspartate-directed proteases) belong to the family of cysteine proteases and are involved in networks controlling cell death (apoptosis and necrosis) and inflammation. 12 human caspases have been described so far (1.). Human Caspases have been classified according to their roles in apoptosis (Caspase-3, -6, -7, -8, and -9) and inflammation (Caspase-1, -4, -5, and -12). Caspase-2, -10, and -14 can be less easily classified concerning the function (for an overview see 2.).

So let’s take a further look at their role, and some of the tools available to investigate and screen compounds modifying Caspase activities.

[Read more…]