Necrosis

Excerpt

Irreversible cell injury and eventual cell death due to pathological processes are termed necrosis. It is an uncontrolled cell death that results in swelling of the cell organelles, plasma membrane rupture and eventual lysis of the cell, and spillage of intracellular contents into the surrounding tissue leading to tissue damage. Unlike programmed cell death known as apoptosis which generates from intrinsic signals, necrosis occurs due to overwhelming noxious stimulus from outside the cell and is almost always associated with inflammatory responses due to the release of heat shock proteins, uric acid, ATP, DNA, and nuclear proteins, which cause inflammasome activation and secretion of proinflammatory cytokine interleukin-1 beta (IL1). Typically, necrosis is not associated with caspase activation or normal development, but different types of regulated necrosis have been described, such as necroptosis, pyroptosis, and ferroptosis. like apoptosis, enzymatic pathways such as caspases, kinases, and the polyubiquitin system, have the main role in necroptosis and pyroptosis. Necroptosis, especially, shares several key processes with both apoptosis and autophagy. Synchronized regulated necrosis is the result of specific lipid peroxidation in ferroptosis.