The APOE-R136S mutation protects against APOE4-driven Tau pathology, neurodegeneration and neuroinflammation.

Maxine R Nelson, Peng Liu, Ayushi Agrawal, Oscar Yip, Jessica Blumenfeld et al.

Nature neuroscience 2023

Apolipoprotein E4 (APOE4) is the strongest genetic risk factor for late-onset Alzheimer's disease (LOAD), leading to earlier age of clinical onset and exacerbating pathologies. There is a critical need to identify protective targets. Recently, a rare APOE variant, APOE3-R136S (Christchurch), was found to protect against early-onset AD in a PSEN1-E280A carrier. In this study, we sought to determine if the R136S mutation also protects against APOE4-driven effects in LOAD. We generated tauopathy mouse and human iPSC-derived neuron models carrying human APOE4 with the homozygous or heterozygous R136S mutation. We found that the homozygous R136S mutation rescued APOE4-driven Tau pathology, neurodegeneration and neuroinflammation. The heterozygous R136S mutation partially protected against APOE4-driven neurodegeneration and neuroinflammation but not Tau pathology. Single-nucleus RNA sequencing revealed that the APOE4-R136S mutation increased disease-protective and diminished disease-associated cell populations in a gene dose-dependent manner. Thus, the APOE-R136S mutation protects against APOE4-driven AD pathologies, providing a target for therapeutic development against AD.

18 Figures Extracted

Fig. 1

Homozygous R136S mutation rescues APOE4-promoted Tau pathology in tauopathy mice. a , Schematic of CRISPR–Cas-9-mediated gene editing strategy to gene...

Fig. 2

Homozygous R136S mutation protects against APOE4-induced p-Tau accumulation in human neurons. a – d , Representative western blot images ( a ) and qua...

Fig. 3

Homozygous R136S mutation protects against APOE4-induced p-Tau accumulation by reducing Tau uptake via the HSPG pathway. a , Diagram of Tau-488 uptake...

Fig. 4

The R136S mutation ameliorates APOE4-driven neurodegeneration in tauopathy mice. a , Representative images of 10-month-old PS19-E4, PS19-E3, PS19-E4-S...

Fig. 5

The R136S mutation reduces APOE4-driven gliosis in tauopathy mice. a , b , Representative images of GFAP immunostaining of astrocytes in the hippocamp...

Fig. 6

snRNA-seq reveals protective effects of the R136S mutation on APOE4-driven neuronal and oligodendrocytic deficits in mice. a , UMAP projection of 38 d...

Fig. 7

The APOE4-R136S mutation increases disease-protective and decreases disease-associated astrocyte subpopulations. a , UMAP projection of 12 astrocyte s...

Fig. 8

The APOE4-R136S mutation increases disease-protective and decreases disease-associated microglial subpopulations. a , UMAP projection of 15 microglia ...

Extended Data Fig. 1

Extended Data Fig. 1 PMC

Generation of human APOE4-R136S knock-in mice and APOE4-R136S hiPSC lines by CRISPR/Cas-9-mediated gene editing. a , Schematic of generating human APO...

Extended Data Fig. 2

Extended Data Fig. 2 PMC

Histopathological analyses of 10-month-old WT and 6-month-old PS19-E3, PS19-E4, PS19-E4-S/S, and PS19-E4-R/S mice. a , Representative images of 10-mon...

Extended Data Fig. 3

Extended Data Fig. 3 PMC

Characterization of E4-S/S and E4-R/S hiPSC lines and neuronal differentiation. a , Karyogram of E4-S/S-A, E4-S/S-B, E4-S/S-C, E4-R/S-A, and E4-R/S-B ...

Extended Data Fig. 4

Extended Data Fig. 4 PMC

Measurement of neuronal uptake of Tau-488 by flow cytometry. a , Internal controls of Tau-488 uptake assay as measured by median fluorescent intensity...

Extended Data Fig. 5

Extended Data Fig. 5 PMC

Quantifications and correlations between % coverage area of glial markers and hippocampal volume in tauopathy mice. a,b , Quantification of % GFAP (a)...

Extended Data Fig. 6

Extended Data Fig. 6 PMC

Quality control measures in snRNA-seq analysis of tauopathy mice with different APOE genotypes. a , Dot-plot depicting normalized average expression o...

Extended Data Fig. 7

Extended Data Fig. 7 PMC

snRNA-seq analysis of disease-protective neuronal clusters and disease-associated oligodendrocyte cluster. a,b , KEGG pathway enrichment dot-plot of t...

Extended Data Fig. 8

Extended Data Fig. 8 PMC

snRNA-seq analysis of astrocyte and microglia subclusters. a , Feature plot showing relative levels of normalized human APOE gene expression across al...

Extended Data Fig. 9

Extended Data Fig. 9 PMC

The R136S mutation reduces APOE4-induced neutral lipid accumulation in astrocytes and microglia in tauopathy mice. a , Representative images of neutra...

Extended Data Fig. 10

Extended Data Fig. 10 PMC

PCA clustering of selected hippocampal cell clusters as well as astrocyte and microglia subclusters against all measured pathologies. Principal compon...