Antisense Oligonucleotide-Mediated Polycystin 1 Upregulation by Enhancing PKD1 Translation Has the Potential to Treat ADPKD

Background: ADPKD is a genetic disorder characterized by cyst development and growth in the kidneys. Most ADPKD cases are caused by haploinsufficient mutations in the PKD1 gene, which encodes polycystin-1 (PC1). Thus, increasing PC1 protein levels represents a promising disease-modifying approach to address ADPKD at its root cause. This concept has been clinically validated by anti-miR-17 antisense oligonucleotides (ASOs), which indirectly upregulate PC1 expression. However, since individual microRNA can regulate multiple mRNAs, a more specific strategy is desirable. Methods: ASOs were designed using the Antisense-Coupled Translation Upregulation (ACT-UP1) technology developed at Arnatar. ASOs were delivered into different cells including ADPKD patient derived cells, and the effects on PC1 protein level, cAMP, Ca2+, and cyst development were analyzed. Potential off-target effect was evaluated using Western blotting and RNA sequencing. In vivo studies were conducted in male BALB/c mice, through subcutaneously injection. Results: The optimized ASO, ART5, increased PC1 protein levels by approximately 50% across various stable cell lines derived from human, mouse, and monkey. In patient-derived cells (WT9-7), ART5 increased PC1 protein levels by up to twofold, accompanied with reduced cAMP levels, decreased mTOR pathway activity, increased Ca2+ level, and diminished cyst formation. No off-target effects were detected, suggesting the high specificity of ART5. In vivo, ART5 administration increased PC1 protein levels up to 2 fold, with elevated PC1 levels persisting four weeks post-treatment. Conclusion: Together, our results demonstrate that the upregulatory ASO, ART5, specifically increases PC1 protein levels across multiple cell types and species by 50%-100%. The upregulated PC1 protein is functional, and ART5 treatment effectively inhibits cyst development. In vivo, ART5 exhibits high efficacy and a sustained pharmacodynamic effect, supporting the feasibility of less frequent clinical dosing. Collectively, these findings suggest that ART5 represents a promising therapeutic strategy for potential treatment of ADPKD. Funding: Commercial Support - Arnatar Therapeutics, Inc