Cell Death — Apoptosis

Caspases: The Executioners of Cellular Fate

Your brain is a trained assassin. I kid you not. Let me explain.

There are two ways your brain kills cells, riveting I know. Necrosis and Apoptosis, the latter happening more often.

What is it?

Apoptosis is programmed cell death (think: in the new out with the old). A couple of reasons why apoptosis may occur:

• Its old and doesn’t function properly so its replaced with newer healthier cells to keep balance
• Damaged (we don’t want that to multiply trust me (its cancer causing!))
• Immune system regulation
• Homeostasis (50–70 BILLION cells die daily due to apoptosis…which is roughly 0.114% of the cells in our body mindblowing!)
• Shaping Embryonic Development: You could’ve been a webbed baby
• Fighting Infections
• Eliminating Immune Cells

The Process:

There are two types of ways apoptosis can occur: the Intrinsic and Extrinsic Pathway both of which include caspase, a vital part that does the dirty work (aka the murdering).

Extrinsic:

Extrinsic is when external (EXtrinsic, EXternal) stimuli begin the process of apoptosis. Such as death receptors (crazy how much a single cell contains). We got mitochondria, death, nucleus, ribosomes. totally normal. These death receptors (like a fire alarm or the red button and barbie’s closet) are unique sensors on the surface of a cell. They detect any signs or symptoms that may lead to an unhe

althy or dying cell. Telling the procaspase (the inactive version of a caspase located in the cytoplasm) “hey we got a problem here”. Which triggers it and long story short any nearby cells get a full reenactment of Saw. It goes along chopping DNA, basically brutally murdering the cell from the inside. Breaking down proteins that support the cell and anything that can get in its way. The remnants of the cell is then engulfed (or eaten) by neighboring cells or phagocytes (specialized white blood cells or in other words trained cannibals). Without releasing any harmful material.

Intrinsic

The intrinsic pathway can be caused by DNA damage, oxidative stress, or growth factor issues. In which caspases are activated is using proteins. More specifically the cytochrome c. big word I know. Which just joins forces with other proteins to create this mega star often referenced as the gatekeeper (I swear I’m not making this up). Which is called the apoptosome The apoptosome will activate the caspases. P53 can jumpstart the release in cytochrome c by triggering the mitochondria to release it. It can also be triggered when it stops receiving signals from nearby cells which can begin the phase.

Conclusion:

Apoptosis isn’t bad in fact it’s crucial! Making sure your organs work properly and killing anything could kill you. Your own knight in shining armor. Though if not done regularly it can lead to cancer cells, Alzheimer’s, and other not-so-fun diseases. Learn more cellular and brain related facts at my page!