DNA nanoflower Oligo-PROTAC for targeted degradation of FUS to treat neurodegenerative diseases.

Oligonucleotide-based medicine faces challenges in efficiently crossing the blood-brain barrier and rapidly reducing toxic proteins. To address these challenges, here we establish an integrated modality, brain-penetrant DNA nanoflowers incorporated with oligonucleotide-based proteolysis targeting chimeras. Using FUS as a proof-of-concept, mutations of which cause frontotemporal dementia and amyotrophic lateral sclerosis, we demonstrate that a FUS-engaging RNA oligonucleotide crosslinked to a ligand for Cereblon efficiently degrade FUS and its cytoplasmic disease-causing mutants through a ubiquitin-proteasomal pathway. The DNA nanoflower contains hundreds of oligonucleotide binding sites and transferrin receptor-engaging aptamers, allowing efficient loading of the oligonucleotide-based degrader and engaging transferrin receptors for brain delivery. A single dose intravenous injection of this modality reaches brain parenchyma within 2 h and degrades 80% FUS protein there, sustained for two weeks without noticeable toxicity. DNA nanoflower oligonucleotide-based degrader is a therapeutic strategy for neurodegenerative diseases that leverages the advantages of designer oligonucleotides and targeted protein degradation.