Silencing Apoe with divalent-siRNAs improves amyloid burden and activates immune response pathways in Alzheimer's disease

Alzheimers Dement. 2024 Apr;20(4):2632-2652. doi: 10.1002/alz.13703. Epub 2024 Feb 20.

Abstract

Introduction: The most significant genetic risk factor for late-onset Alzheimer's disease (AD) is APOE4, with evidence for gain- and loss-of-function mechanisms. A clinical need remains for therapeutically relevant tools that potently modulate APOE expression.

Methods: We optimized small interfering RNAs (di-siRNA, GalNAc) to potently silence brain or liver Apoe and evaluated the impact of each pool of Apoe on pathology.

Results: In adult 5xFAD mice, siRNAs targeting CNS Apoe efficiently silenced Apoe expression and reduced amyloid burden without affecting systemic cholesterol, confirming that potent silencing of brain Apoe is sufficient to slow disease progression. Mechanistically, silencing Apoe reduced APOE-rich amyloid cores and activated immune system responses.

Discussion: These results establish siRNA-based modulation of Apoe as a viable therapeutic approach, highlight immune activation as a key pathway affected by Apoe modulation, and provide the technology to further evaluate the impact of APOE silencing on neurodegeneration.

Keywords: Alzheimer's Disease; Apoe; RNAi; neurodegeneration; oligonucleotide therapeutics; siRNA.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Alzheimer Disease* / pathology
  • Amyloid / metabolism
  • Amyloid beta-Peptides / metabolism
  • Amyloidogenic Proteins / metabolism
  • Animals
  • Apolipoprotein E4 / genetics
  • Apolipoproteins E / genetics
  • Apolipoproteins E / metabolism
  • Brain / pathology
  • Mice
  • Mice, Transgenic
  • RNA, Small Interfering / genetics
  • RNA, Small Interfering / metabolism

Substances

  • RNA, Small Interfering
  • Apolipoproteins E
  • Apolipoprotein E4
  • Amyloid
  • Amyloidogenic Proteins
  • Amyloid beta-Peptides