neutrophil apoptotic process

Definition

Target type: biologicalprocess

Any apoptotic process in a neutrophil, any of the immature or mature forms of a granular leukocyte that in its mature form has a nucleus with three to five lobes connected by slender threads of chromatin, and cytoplasm containing fine inconspicuous granules and stainable by neutral dyes. [CL:0000775, GOC:add, GOC:mtg_apoptosis, PMID:12752675, PMID:12960266]

Neutrophils are short-lived phagocytic cells that play a critical role in the innate immune response. Their rapid elimination by apoptosis is crucial for maintaining tissue homeostasis and preventing inflammatory damage. The neutrophil apoptotic process is a highly regulated and complex series of events that involve a cascade of molecular signals.

1. **Initiation:** Apoptosis in neutrophils can be triggered by various stimuli, including growth factor withdrawal, exposure to reactive oxygen species (ROS), and engagement of death receptors. These signals activate intracellular signaling pathways, such as the caspase cascade and the mitochondrial apoptotic pathway.

2. **Mitochondrial Dysfunction:** Mitochondria play a central role in apoptosis by releasing pro-apoptotic proteins, such as cytochrome c, into the cytoplasm. This release is triggered by the activation of pro-apoptotic proteins like Bax and Bak, which permeabilize the mitochondrial outer membrane.

3. **Caspase Activation:** The release of cytochrome c into the cytoplasm activates caspase-9, an initiator caspase, which then triggers a cascade of caspase activation. Caspase-3, a key executioner caspase, cleaves and activates downstream targets involved in the dismantling of the cell.

4. **Cell Death:** The activation of caspases leads to a series of biochemical events that dismantle the cell. This includes the breakdown of DNA, cytoskeletal proteins, and nuclear proteins. The cell shrinks and condenses, forming apoptotic bodies that are engulfed by phagocytes.

5. **Phagocytosis and Clearance:** Apoptotic neutrophils exhibit specific "eat me" signals, including phosphatidylserine exposure on the cell surface. These signals attract phagocytes, such as macrophages, which engulf and digest the apoptotic bodies. This process prevents the release of inflammatory contents and ensures the safe removal of dead cells.

The precise mechanisms of neutrophil apoptosis can vary depending on the triggering stimulus. However, the overall process ensures the orderly elimination of neutrophils, maintaining tissue integrity and preventing excessive inflammation.'
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Proteins (2)

Compounds (23)