Development of a chemically modified antisense oligonucleotide that destabilizes the AGO2–miR-204-5p complex as a disease-modifying therapy for osteoarthritis

Abstract Background Osteoarthritis (OA) is a prevalent degenerative joint disease lacking approved disease-modifying therapies. A key pathogenic driver is a senescence-induced microRNA, miR-204-5p, which suppresses glycosaminoglycan-rich proteoglycan anabolism in chondrocytes, thereby driving chondrocytes toward a catabolic state that progressively degrades cartilage. This study aimed to evaluate LF-ASO-001, a chemically optimized antisense oligonucleotide designed to potently degrade miR-204-5p, as a potential disease-modifying therapy for OA. Methods The structural mechanism of LF-ASO-001 was characterized through molecular docking and molecular dynamics simulations of the Argonaute2 (AGO2)-miR-204-5p complex. To validate its functional activity, we utilized primary murine chondrocytes under stress-induced senescence and miR-204-overexpressing human chondrocytes to assess the restoration of anabolic homeostasis. In vivo pharmacokinetics and safety were profiled via fluorescence-based biodistribution assays and comprehensive toxicity studies. Therapeutic efficacy was evaluated in the murine destabilization of the medial meniscus model. The study design included both an early intervention strategy to assess the prevention of disease progression and a delayed treatment regimen to evaluate the modulation of established pathology following intra-articular administration. Results Molecular dynamics simulations revealed that LF-ASO-001 displaces the 3’ end of miR-204-5p from the AGO2 PAZ (Piwi-Argonaute-Zwille) domain, destabilizing the miRNA-loaded complex. LF-ASO-001 suppressed senescence-associated inflammatory and matrix-remodeling phenotypes while restoring anabolic gene expression in senescent chondrocytes. A single intra-articular injection achieved durable cartilage retention and robust efficacy in a post-traumatic OA model in mice. LF-ASO-001 not only prevented joint degeneration but also mitigated established disease in a delayed-treatment model, restoring weight-bearing function. In comparative efficacy studies, LF-ASO-001 provided more robust structural protection than a clinical-stage small-molecule candidate and matched the analgesic benefit of dexamethasone. LF-ASO-001 demonstrated a favorable safety profile, showing no local joint toxicity, adverse effects on serum clinical biochemistry, or alterations in subchondral bone architecture. Conclusions LF-ASO-001 is a promising disease-modifying OA drug candidate that couples durable single-dose pharmacology with joint preservation and symptomatic relief through targeted degradation of miR-204-5p via AGO2 complex destabilization.