The APOE isoforms differentially shape the transcriptomic and epigenomic landscapes of human microglia xenografted into a mouse model of Alzheimer's disease.
Level 5 - mechanism / opinion, no new human data
Preclinical animal xenotransplantation and bench sequencing study without human clinical endpoints.
PubMed 40419479 · doi:10.1038/s41467-025-60099-4
What was done
Human microglia expressing different APOE isoforms were xenotransplanted into the brains of male APP NL-G-F mouse models of Alzheimer's disease. The researchers performed RNA-sequencing to profile gene expression and ATAC-sequencing to evaluate chromatin accessibility across APOE genotypes.
What was found
The abstract reports no numerical values or effect sizes. Widespread transcriptomic and epigenomic differences were observed across APOE genotypes. Functional signatures indicated that APOE4 microglia had impaired proliferation, migration, and immune responses, whereas APOE2 microglia displayed increased phagocytic capacity and elevated DNA-binding of the vitamin D receptor.
Why it matters
The findings provide a mechanistic epigenomic and transcriptomic basis for how APOE4 confers increased risk and APOE2 confers protection in Alzheimer's disease via human microglial functional changes.
Limits
The study was conducted exclusively in a xenograft mouse model using only male mice, which may not fully recapitulate human clinical disease or female-specific biology. The abstract does not disclose exact sample sizes, cell line counts, or quantitative statistical effect sizes.
Cited by
- supports In Alzheimer's mouse models xenografted with human microglia, APOE4 microglia exhibit higher expression of pro-inflammatory cytokines, impaired protein phagocytosis, and downregulation of genes promoting cellular motility and proliferation compared to APOE2 microglia.
- supports In protective APOE2 microglia, there is enhanced signaling via binding of the vitamin D receptor to DNA.