Apoptosis - Know your basics
🤔What is Apoptosis?
Apoptosis, also called “programmed cell death” is the process where the cell regulates its own death through the production of certain enzymes.
Apoptosis could be triggered by factors such as infections, especially viral infections, misfolding of proteins due to mutations and DNA damage due to mutation, radiation, hypoxia and free radicals.
📝Here are some "Highlights" or a high level overview of Apoptosis
Apoptosis is a homeostatic mechanism.
The nuclear chromatin of the cell shrinks and becomes condensed (usually peripherally – best seen in electron microscopy), a process called pyknosis.
Chromatin material undergoes karyorrhexis, i.e it disintegrates and becomes fragmented.
The cell starts to form blebs on its surface and starts to break off into small fragments called apoptotic bodies.
It is important to understand that apoptosis does not elicit inflammation, unlike another form of cell death called necrosis.
Apoptosis could be initiated by signals from the intrinsic pathway, the extrinsic pathway and the perforin/granzyme pathway.
“BH3 only” proteins comprising of Bim, Bid and Bad proteins block the function of Bcl-2 and Bcl-x.
Caspase 9 is an initiator caspase and activated Caspase 9 molecules activate executioner Caspases 3 and 6 leading to apoptosis of the cell.
Executioner caspases 3 and 6 cause degradation of chromosomal DNA and also degradation of cytoskeletal proteins, which cause the morphological changes such as nuclear fragmentation and cellular shrinkage respectively.
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🔎You could dig deeper into the topic
If ever, you want to go deep into this topic - Apoptosis and get access to the script of this video, we have some great notes, all of which are available on our Revision Ninja - Oral Pathology and Medicine Course bundle!
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