Elucidating brain transport pathways and cell type-dependent gene silencing of a durable lipid–siRNA conjugate administered into cerebrospinal fluid

Year: 2025

Type: article

Abstract: The clinical neurosciences are in the midst of a renaissance spurred by the development of new therapeutic modalities. Short interfering RNAs (siRNAs), in particular, are gaining interest for treating neurological diseases owing to their capacity to sustain inhibition of nearly any gene target. However, to be effective, siRNA therapies must achieve delivery and on-target gene silencing activity in specific sites and cells in the brain. To this end, we developed a lipid-siRNA conjugate (L2-siRNA) that transports effectively throughout the brain when injected into cerebrospinal fluid (CSF). We provide a detailed examination of regional bulk tissue gene silencing in mice, highlighting potent knockdown 5 months after a single injection without detectable toxicity. Intrathecal delivery of L2-siRNA in rats further illustrates effective transport and knockdown using a clinically relevant route of administration. Single-cell RNA sequencing was additionally performed in mice to generate an atlas of cell type-specific knockdown. Lastly, we benchmarked L2-siRNA gene silencing activity in different brain regions against antisense oligonucleotides, a related but different gene silencing modality. Collectively, this work examines properties of lipid-siRNA conjugates that facilitate CSF to brain delivery and supports L2-siRNA as a promising platform for silencing genes implicated in central nervous system disorders.

Source: Nucleic Acids Research

DOI: 10.1093/nar/gkaf600

Institutions: Vanderbilt University, Vanderbilt University Medical Center, Washington University in St. Louis

Language: English

Topic: RNA Interference and Gene Delivery

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $3,992

Funders: American Heart Association, National Institutes of Health, National Institute on Aging, National Heart, Lung, and Blood Institute, National Science Foundation Graduate Research Fellowship Program

Awards: G3220087362, Regulation of High-Density Lipoprotein Function by Small RNA Modifications in Atherosclerosis-Associated Inflammation, Perivascular fibroblasts, vascular fibrosis, and their contributions to cerebral amyloid angiopathy, G734120740, G9000091806, G9000129821, Targeting brain myeloid cells with siRNA-lipid conjugates for treatment of Alzheimer's disease

OpenAlex ID: W4411969737