Multi-Target Gene Therapy for Osteoarthritis: A Computational and Structural Analysis Framework

Background: Osteoarthritis (OA) remains therapeutically intractable despite advances in regenerative medicine. Single-target interventions—including mesenchymal stromal cells, platelet-rich plasma, and gene therapies—consistently yield transient symptomatic relief without durable structural modification. Objective: This study proposes a multi-target gene therapy strategy integrating computational structural analysis and molecular docking with clinical observations to address the dual-axis nature of OA pathogenesis. Methods: Crystal structures of key therapeutic proteins (IL-1Ra, SOX9, IGF-1) were analysed using PyMOL to validate functional domain completeness and inform vector engineering. Molecular docking was performed using AutoDock Vina 1.2.5 to evaluate inhibitor binding to ADAMTS-5 catalytic domain (PDB: 3HY7) and assess this enzyme as a tractable therapeutic target. A theoretical framework was developed based on the Dual-Axis Model of OA progression, distinguishing suppressible inflammatory signaling (Axis I) from recalcitrant mechano-structural degradation (Axis II). Results: Structural analysis supports that therapeutic transgenes preserve critical functional domains required for secretory (IL-1Ra, IGF-1) and nuclear (SOX9) functions. Molecular docking of a hydroxamate-based inhibitor (Compound 097) to ADAMTS-5 yielded a binding affinity of -4.795 kcal/mol, with nine distinct binding poses identified, supporting the view that the catalytic domain is structurally accessible, although binding affinity remains modest. However, monotherapy approaches targeting either axis alone consistently fail—Axis I interventions (IL-1Ra, corticosteroids) provide transient relief without structural benefit, while Axis II monotherapies (FGF-18, MMP inhibitors) show limited efficacy. We propose a dual-vector AAV system simultaneously targeting: (1) inflammatory suppression (IL-1Ra), (2) anabolic transcription (SOX9), (3) growth signalling (IGF-1), and (4) catabolic inhibition (ADAMTS-5 shRNA). This addresses payload constraints while preserving multi-target functionality. Conclusions: The persistent failure of single-target biologics reflects axis-specific intervention mismatches. Computational analysis, molecular docking, and clinical experience converge on the necessity of multi-modal strategies. These results are hypothesis-generating and should be interpreted as a design framework rather than preclinical validation. The proposed dual-vector system is structurally plausible and technically feasible, providing a concrete basis for experimental testing.