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Cartilage targeting hydrogel nanoplatform degrades BRD4 to alleviate osteoarthritis via Nav1.7 axis
Qirui Zhao1,2, Tongtong Xu3, Zuchao Du4
1Department of Orthopedics, The First Affiliated Hospital of Henan University, Henan University, Kaifeng, China.
Abstract:
Osteoarthritis (OA) is a common degenerative joint disease with limited disease-modifying therapies. Emerging evidence suggests that epigenetic dysregulation contributes to cartilage degeneration, but effective strategies to selectively target these pathways remain lacking. Here we show that the BRD4/Nav1.7 axis drives inflammatory and metabolic dysfunction in OA. Integrated single-cell and transcriptomic analyses identify BRD4 as a key regulator that enhances Nav1.7 transcription, promoting mitochondrial impairment and catabolic activation in chondrocytes. To therapeutically target this pathway, we develop a biomimetic hydrogel system incorporating chondrocyte membrane-coated nanoparticles for cartilage-specific delivery of a BRD4 proteolysis-targeting chimera (PROTAC), a molecule designed to induce selective protein degradation. This nanoplatform enables efficient intra-articular delivery, immune evasion and targeted retention in cartilage. Treatment suppresses inflammatory responses, restores mitochondrial function and reduces cartilage degeneration and pain behaviors in two mouse models of OA. These findings establish targeted BRD4 degradation as a disease-modifying strategy and provide a precision nanotherapeutic platform for OA.
Insights
Researchers identified the BRD4/Nav1.7 pathway driving osteoarthritis (OA). They developed a targeted nanoparticle therapy delivering a BRD4 degrader, effectively reducing OA symptoms and cartilage damage in mice.
Area of Science:
- Biomedical Engineering
- Molecular Biology
- Rheumatology
Background:
- Osteoarthritis (OA) is a prevalent degenerative joint disease with inadequate disease-modifying treatments.
- Epigenetic dysregulation is implicated in OA pathogenesis, yet targeted therapeutic strategies are scarce.
- The BRD4/Nav1.7 axis is emerging as a critical factor in OA-related cellular dysfunction.
Purpose of the Study:
- To investigate the role of the BRD4/Nav1.7 axis in OA pathogenesis.
- To develop a novel nanotherapeutic platform for targeted delivery of a BRD4-targeting agent.
- To evaluate the therapeutic efficacy of this approach in preclinical OA models.
Main Methods:
- Integrated single-cell and transcriptomic analyses to identify key regulators in OA.
- Development of a biomimetic hydrogel system with chondrocyte membrane-coated nanoparticles.
- Cartilage-specific delivery of a BRD4 proteolysis-targeting chimera (PROTAC) via the nanoplatform.
- Assessment of therapeutic effects in mouse models of OA, including pain behavior and cartilage integrity.
Main Results:
- BRD4 was identified as a key regulator enhancing Nav1.7 transcription, leading to mitochondrial impairment and catabolic activation in chondrocytes.
- The developed nanoplatform demonstrated efficient intra-articular delivery, immune evasion, and targeted cartilage retention.
- Treatment with the BRD4 PROTAC suppressed inflammation, restored mitochondrial function, and reduced cartilage degeneration and pain behaviors in OA mouse models.
Conclusions:
- Targeted degradation of BRD4 represents a promising disease-modifying strategy for osteoarthritis.
- The developed precision nanotherapeutic platform offers a novel approach for OA treatment.
- This study highlights the therapeutic potential of targeting the BRD4/Nav1.7 axis in degenerative joint diseases.
