Abstract
Oligonucleotides are short nucleic acid polymers that have emerged as a novel class of therapeutics, showing clinical success in the past decade due to advances in chemistry. However, their broader clinical application remains limited by delivery challenges, restricted tissue distribution, and lack of polypharmacology. While many are addressing delivery and distribution, few have explored how different oligonucleotides work in combination or how to design single oligonucleotides that act on multiple targets. This is especially relevant for neurological disorders, most of which are polygenic.
In the first part of this dissertation, I investigated how single-stranded antisense oligonucleotides (ASOs) with different mechanisms act in tandem. Using ASOs that upregulate SCN1A mRNA, I demonstrated synergistic mRNA upregulation. This is clinically significant, as SCN1A deficiency causes Dravet Syndrome (DS), a severe childhood epilepsy. Upregulating SCN1A is a promising treatment for DS.
In the second part, I explored combinations of small interfering RNAs (siRNAs) to reduce amyloid beta (Aβ) and phosphorylated tau (p-tau)—hallmarks of Alzheimer’s Disease (AD). This led to the discovery of key effects involving mTOR signaling and the development of a siRNA combination targeting APP and MAPT to reduce both Aβ and p-tau.
Lastly, I developed a novel method to chemically link two oligonucleotides into a single, multi-targeting molecule. Altogether, my dissertation lays the groundwork for designing next-generation, multi-targeting oligonucleotide therapeutics.