Cell death has traditionally been subdivided into regulated (apoptosis) and unregulated (necrosis) forms. While apoptosis has always been recognized to be a pathway of highly orchestrated signaling events, necrosis or necrotic cell death is known as a fortuitous and unregulated means of cell death that is induced by nonspecific and nonphysiological stress.
Here we discuss the main differences between these two cell death modes.
What is Necrosis?
Necrosis is the premature death of a set of cells or any tissue of an organism. Necrosis is caused by a harmful agent that has caused a severe injury that cannot be repaired or cured by systemic or organic means.What causes it?
Necrosis may be caused by:
- Lack of blood supply to the tissue
- Ischemia reperfusion injury trauma
- Exposure to ionizing radiation trauma
- Chemical or toxic substances
- Infections
- Development of an autoimmune or other diseases
6 Types of Necrosis
Coagulative: A gel-like substance in dead tissue caused by protein denaturation.
Liquefactive: The digestion of dead cells in liquid masses caused by infections.
Caseous: A coagulative and liquefactive necrosis caused by mycobacteria.
Fat: It activates lipases on fatty tissue.
Fibroid: A form of necrosis caused by immune-mediated vascular damage.
Gangrenous: Similar to mummified tissue caused by infection.
What is Necroptosis?
Necroptosis is a programmed cell death that is similar to necrosis. It is characterized by inflammation of cells, dysfunction of mitochondria, permeabilization of the plasma membrane, and the release of cytoplasmic content into extracellular space causing inflammatory reactions in the surrounding tissue.This form of cell death is also associated with mitochondrial reactive oxygen species and unlike apoptosis does not imply DNA fragmentation.
Differences Between Necrosis and Necroptosis
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|
Necrosis |
Necroptosis |
| Type of cell death | Uncontrolled | Controlled |
| Trigger | Trauma, toxic stress, infection | Trauma, toxic stress, infection |
| Morphology | Extensive organelle and cell swelling loss of membrane integrity, release of extracellular contents | Cytoplasmic swelling, rupture of the plasma membrane and spilling of the intracellular content |
| Role of mitochondria | Mitochondrial dysfunctions, collapse of mitochondrial membrane potential, Failure of ATP production | Mitochondrial dysfunction, production of ROS |
| Inflammatory response | Pro-inflammatory response | Pro-inflammatory response |
| Human condition | Pathological condition | Pathological condition |