What causes Apoptosis?
Apoptosis can be initiated by a number of signals, but they can all be separated into either endogenous or exogenous initators. Exogenous initiators ionduce apoptosis by binding to what is called a “death receptor”. The Fas and Fas ligand systme are an example. Engagement of this receptor initiates a series of signals that eventually activate caspases, the effector molecules of apoptosis. Endogenous signals are many, but include things like significant DNA damage. Virus replication can also induce apoptosis in an effort to kill the cell before the virus can replicate. These endogenous signals also result in capsase activation, but through different biochemical pathways. All pathways result in the activation of caspases, enzymes which essentially take apart the cell, degrading chromatin, etc., in a way that does not induce inflammmation and the death of neighboring, healthy cells. I am trying to simpify a very complicated topic. I hope I didn’t oversimplify.
