Tumour necrosis factor alpha-induced neuronal loss is mediated by microglial phagocytosis

Area of Science:

• Neuroscience
• Immunology
• Cell Biology

Background:

• Tumour necrosis factor-α (TNF-α) is a pro-inflammatory cytokine implicated in various brain pathologies.
• TNF-α is associated with neuronal loss in neurological conditions.

Purpose of the Study:

• To investigate the role of TNF-α in neuronal loss.
• To elucidate the mechanism by which TNF-α induces neurodegeneration, focusing on microglial involvement.

Main Methods:

• Utilized neuronal-glial co-cultures treated with TNF-α.
• Assessed microglial proliferation and phagocytosis.
• Investigated the effect of blocking microglial phagocytic receptors (vitronectin and P2Y6) and MFG-E8.

Main Results:

• TNF-α increased microglial proliferation and phagocytosis in co-cultures.
• Neuronal loss was observed following TNF-α treatment.
• Eliminating microglia or inhibiting microglial phagocytosis prevented TNF-α-induced neuronal death.
• Blocking specific phagocytic pathways (vitronectin, P2Y6, MFG-E8) abrogated TNF-α-mediated neurotoxicity.

Conclusions:

• TNF-α induces neuronal loss primarily through microglial activation and subsequent phagocytosis of neurons.
• This process, termed phagoptosis, represents a key mechanism of neurodegeneration in the context of TNF-α signaling.