Cell death has traditionally been subdivided into regulated (necroptosis) 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 non-physiological stress. Here we discuss the main differences between these two cell death modes.

What is Necrosis?

Process of necrosis

Necrosis - Pathologic Cell Death. Cell injury which results in the premature death of cells in living tissue. Image Credit: Designua / Shutterstock

It is the premature death of a set of cells or any tissue of the 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 is caused by a harmful agent that has caused a severe injury that cannot be repaired or cured by systemic or organic means. These may include:

  • 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

It is a gel-like substance in dead tissue caused by protein denaturation.

Liquefactive

It is the digestion of dead cells in liquid masses caused by infections.

Caseous

It is a coagulative and liquefactive necrosis caused by mycobacteria.

Fat

It activates lipases on fatty tissue.

Fibroid

It is a form of necrosis caused by immune-mediated vascular damage.

Gangrenous

It is similar to mummified tissue caused by infection.

READ MORE: Guide to Necrosis Signaling Pathway Inhibitors

What is Necroptosis?

Pathways in cell that can lead to necroptosis

Necroptosis pathways

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.

READ MORE: A Guide to Necroptosis Inhibitors

Differences

Table 1

Differences in the characteristics of necrosis and necroptosis

Characteristics

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

 

Sources

  • “Necrosis.” Wikipedia, Wikimedia Foundation, 5 May 2019, en.wikipedia.org/wiki/Necrosis.
  • “Necroptosis.” Wikipedia, Wikimedia Foundation, 26 Nov. 2018, en.wikipedia.org/wiki/Necroptosis.