Lipid nanoparticle delivery promotes cell-type-specific distribution of antisense oligonucleotides in the brain

ABSTRACT: Antisense oligonucleotides (ASOs) are being actively investigated as potential therapeutics for a broad range of neurodegenerative diseases. While these small oligonucleotides have been effective in the clinic, many basic questions regarding ASO internalization, trafficking, and modes of enhancing delivery remain. To address these questions, we investigated how lipid nanoparticle (LNP) delivery affects ASO uptake and distribution in the brain. We show that ASOs are internalized and active in central nervous system (CNS) cell types both in vivo and in vitro. While differential cellular activity and polarization states do not affect ASO potency, encapsulating ASOs in LNPs increases ASO activity up to 100-fold in cultured CNS cells. This dramatic increase in efficacy is facilitated by the intracellular trafficking of ASOs away from lysosomes or enhanced ASO uptake, which is cell-type-specific. We assessed the translatability of these results by screening ASO-LNPs in vitro and intracerebroventricularly injecting top performing formulations in mice. ASO-LNP delivery induced a strong ASO-dependent microgliosis response in the brain revealing that LNP encapsulation cannot mask ASO-mediated toxicity. However, LNP-delivered ASOs did not downregulate mRNA levels in bulk tissue due to changes in ASO distribution. While ASOs distribute widely across the brain after bulk injection, ASO-LNPs are preferentially internalized by cells lining the blood vessels and ventricles. Consistent with our findings in cells, ASOs localize to the endolysosomal system following both ASO and ASO-LNP delivery in the brain as determined using immunoelectron microscopy. These data provide valuable insights into how LNPs regulate ASO uptake and distribution in the brain, and support further development of ASO-LNPs for treating CNS disorders.

ORGANISM(S): Mus musculus

PROVIDER: GSE220777 | GEO | 2023/05/15

REPOSITORIES: GEO