Apoptosis Or Necroptosis? The Caspase-8 Protein Decides

All cells kill themselves intentionally. This is usually a good thing as it helps eliminate disease-causing cells and clears away any unnecessary ones.

Cell death isn't a straightforward event. It can be caused by many factors, such as stress, infection, and pro-cancer signaling. Cells can die in many ways. Cells can die from excessive damage, or they can choose to die by themselves. 

Caspase-8: Executioner, Protector

The protein caspase-8 is a key decision-maker. When cells are activated with extrinsic signals, Caspase-8 is able to cleave additional proteins. The cell then dies through caspase-3, a cell death executer protein. You can also look for Anti-Caspase-8/CASP8 Antibody Picoband online.

The three-dimensional structure of caspase-8: an initiator enzyme in apoptosis - ScienceDirect

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Caspase-8 is also capable of protecting cells against death. It does this by regulating the expression of cFLIPL. Intricately, the same extracellular signals which regulate death induce cFLIPL to be expressed. 

The expression of cFLIPL blocks caspase-8's ability to induce cell death and prolongs the life span. Extracellular signals trigger a third event, activation of the proteins RIPK1, RIPK3, or MLKL. This causes necroptosis, which results in the death of the cell.

What is the balance?

The death type chosen can have significant effects on the body's immune reaction to cancer and other inflammatory diseases. However, necroptotic cells may alarm the surrounding cells and cause massive inflammation.

This balance is important because it's what cells do. What are the roles of cFLIPL/caspase-8? Certain pathogens may cause cFLIPL to be ineffective. This can activate caspase-8, and the cell will die by apoptosis. 

Other pathogens can also interfere with caspase-8's function. Caspase-8 can no longer block RIPK1 or RIPK3, and the balance tiptoes toward necroptosis.