Cholesterol-mediated Lysosomal Dysfunction in APOE4 Astrocytes Promotes α-Synuclein Pathology in Human Brain Tissue

Mesentier-Louro, L. A.; Goldman, C.; Ndayisaba, A.; Buonfiglioli, A.; Rooklin, R. B.; Schuldt, B. R.; Uchitelev, A.; Khurana, V.; Blanchard, J. W.

doi:10.1101/2025.02.09.637107

bioRxiv · 10.1101/2025.02.09.637107

Cholesterol-mediated Lysosomal Dysfunction in APOE4 Astrocytes Promotes α-Synuclein Pathology in Human Brain Tissue

Mesentier-Louro, L. A.·Goldman, C.·Ndayisaba, A.·Buonfiglioli, A.·Rooklin, R. B.·Schuldt, B. R.·Uchitelev, A.·Khurana, V.·Blanchard, J. W.

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Abstract

The pathological hallmarks of neurodegeneration are the aberrant post-translational modification and aggregation of proteins. Genetic factors, like APOE4, increase the prevalence and severity of tau, amyloid, and -synuclein pathologies. However, the human brain is largely inaccessible during this process, limiting mechanistic understanding. Here, we developed an iPSC-based 3D model that integrates neurons, glia, myelin, and cerebrovascular cells into a human brain-like tissue ("miBrain"). Single-nucleus RNA sequencing of miBrains confirmed the presence of diverse cell populations and revealed transcriptional responses to -synuclein pathology. Like the human brain, pathogenic -synuclein is increased in APOE4/4 miBrains. Combinatorial experiments revealed that endolysosomal dysfunction caused by cholesterol accumulation in APOE4/4 astrocytes impairs the degradation of soluble -synuclein leading to a pathogenic transformation that seeds -synuclein inclusions in neurons. Collectively, this study establishes a robust model for investigating protein inclusions in human iPSC-derived brain tissue and highlights the role of astrocytes and cholesterol in APOE4-mediated pathologies.

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Mesentier-Louro, L. A., Goldman, C., Ndayisaba, A., Buonfiglioli, A., Rooklin, R. B., Schuldt, B. R., Uchitelev, A., Khurana, V., Blanchard, J. W.. 2025-02-09. Cholesterol-mediated Lysosomal Dysfunction in APOE4 Astrocytes Promotes α-Synuclein Pathology in Human Brain Tissue. https://doi.org/10.1101/2025.02.09.637107

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