Microglia ferroptosis is regulated by SEC24B and contributes to neurodegeneration

Area of Science:

• Neuroscience
• Cell Biology
• Iron Metabolism

Background:

• Iron dysregulation is linked to neurodegenerative diseases like Parkinson's disease (PD).
• Iron-laden microglia are observed in affected brain areas, but their role in PD pathogenesis is unclear.
• The precise mechanisms by which iron accumulation impacts microglia and drives neurodegeneration require elucidation.

Purpose of the Study:

• To investigate the impact of iron overload on human induced pluripotent stem cell-derived microglia (iPSC-microglia).
• To determine the role of microglial ferroptosis in iron-induced neurotoxicity.
• To identify novel regulators of microglial iron response and ferroptosis.

Main Methods:

• Utilized a tri-culture system with iPSC-microglia to model neuroinflammation.
• Induced iron overload and assessed microglial response, including ferroptosis and transcriptional changes.
• Performed a genome-wide CRISPR screen to identify genes regulating ferroptosis in microglia.

Main Results:

• iPSC-microglia are highly sensitive to iron and undergo ferroptosis, an iron-dependent cell death.
• Iron overload induces a transcriptional shift in microglia resembling signatures found in PD brains.
• Microglia depletion significantly reduced iron-induced neurotoxicity in the tri-culture model.
• Identified SEC24B as a novel regulator of ferroptosis in microglia.

Conclusions:

• Microglial iron overload and subsequent ferroptosis play a critical role in neurodegeneration.
• Targeting microglial iron metabolism and ferroptosis pathways presents a potential therapeutic avenue for PD.
• SEC24B and other identified regulators are key players in microglial iron homeostasis and ferroptosis.