Endogenous ADAR-mediated RNA editing in non-human primates using stereopure chemically modified oligonucleotides

Area of Science:

• Biochemistry
• Molecular Biology
• RNA Therapeutics

Background:

• RNA editing technologies hold therapeutic promise but face challenges in animal model translation.
• Adenosine deaminases acting on RNA (ADAR) enzymes are key targets for RNA modification.
• The ADAR1 p110 isoform is ubiquitously and constitutively expressed, making it a relevant target.

Purpose of the Study:

• To develop and characterize AIMers for efficient and specific RNA editing.
• To evaluate the in vitro and in vivo efficacy of chemically modified AIMers.
• To assess the therapeutic potential of AIMers in animal models.

Main Methods:

• Design and synthesis of chemically modified oligonucleotides (AIMers).
• In vitro assessment of AIMer potency and editing efficiency.
• In vivo studies in non-human primates targeting hepatocytes with N-acetylgalactosamine (GalNAc).

Main Results:

• Fully chemically modified AIMers with stereopure backbones enhanced editing efficiency 100-fold in vitro.
• In vivo, AIMers achieved up to 50% editing in non-human primate liver.
• No bystander editing was observed for the endogenous ACTB transcript, and editing persisted for at least one month.

Conclusions:

• Stereopure AIMers demonstrate potent and specific RNA editing capabilities in vivo.
• AIMers show promise for therapeutic applications targeting endogenous RNA transcripts.
• Further investigation into stereopure AIMers is warranted for their therapeutic potential.