Cholesterol dysregulation in APOE4 astrocytes promotes α-synuclein pathology in miBrains.

Cholesterol buildup in APOE4 astrocytes drives α-synuclein aggregation, increasing pathology by 50% in human brain-like tissue models.

• Why it matters: Understanding how genetic risk factors like APOE4 contribute to neurodegenerative protein aggregation is crucial for developing targeted therapies, yet human brain mechanisms remain poorly understood.
• What they did: Researchers created a human iPSC-derived 3D "miBrain" model incorporating neurons, glia, myelin, and cerebrovascular cells, and used single-nucleus RNA sequencing to analyze cellular responses to α-synuclein pathology.
• The result: Findings show that cholesterol accumulation in APOE4/4 astrocytes impairs endolysosomal degradation of soluble α-synuclein, promoting its aggregation and seeding neuronal inclusions, revealing potential therapeutic targets.