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A Novel BD2-Selective Inhibitor of BRDs Mitigates ROS Production and OA Pathogenesis
Hyemi Lee1, Jihye Choe2, Min-Hee Son2
1Department of Biological Sciences, Sungkyunkwan University, Suwon 16419, Republic of Korea.
Abstract:
Bromodomain and extra-terminal domain (BET) family proteins regulate transcription and recognize lysine residues in histones. Selective BET inhibitors targeting one domain have attracted attention because they maintain normal physiological activities, whereas pan (nonselective) BET inhibitors do not. Osteoarthritis (OA) is a joint disorder characterized by cartilage degeneration for which no treatment currently exists. Here, we investigated whether the selective inhibition of BET proteins is an appropriate therapeutic strategy for OA. We focused on the development and characterization of 2-(4-(2-(dimethylamino)ethoxy)-3,5-dimethylphenyl)-5,7-dimethoxyquinazolin-4(3H)-one (BBC0906), a novel bromodomain 2 (BD2)-specific inhibitor designed to suppress OA progression. Using a DNA-encoded chemical library (DEL) screening approach, BBC0906 was identified because of its high affinity with the BD2 domain of BET proteins. BBC0906 effectively reduced reactive oxygen species (ROS) production and suppressed catabolic factor expression in chondrocytes in vitro. Moreover, in an OA mouse model induced by the destabilization of the medial meniscus (DMM), BBC0906 intra-articular injection attenuated cartilage degradation and alleviated OA. Importantly, BBC0906 selectively inhibits the BD2 domain, thus minimizing its potential side effects. We highlighted the therapeutic potential of targeting BET proteins to modulate oxidative stress and suppress cartilage degradation in OA. BBC0906 is a promising candidate for OA treatment, offering improved safety and efficacy.
Insights
A new drug, BBC0906, selectively targets bromodomain 2 (BD2) in BET proteins to treat osteoarthritis (OA). This selective inhibition reduces oxidative stress and cartilage damage, offering a promising therapeutic strategy for OA.
Area of Science:
- Biochemistry
- Pharmacology
- Orthopedics
Background:
- Bromodomain and extra-terminal domain (BET) proteins are key transcriptional regulators.
- Selective BET inhibitors offer therapeutic potential with fewer side effects than nonselective inhibitors.
- Osteoarthritis (OA) is a degenerative joint disease with no current effective treatments.
Purpose of the Study:
- To investigate the therapeutic potential of selective BET protein inhibition for osteoarthritis.
- To develop and characterize a novel bromodomain 2 (BD2)-specific inhibitor, BBC0906, for OA treatment.
Main Methods:
- DNA-encoded chemical library (DEL) screening was used to identify BBC0906.
- In vitro studies assessed BBC0906's effects on reactive oxygen species (ROS) and catabolic factors in chondrocytes.
- An in vivo destabilization of the medial meniscus (DMM) mouse model was used to evaluate BBC0906's efficacy in attenuating cartilage degradation.
Main Results:
- BBC0906 demonstrated high affinity for the BET protein BD2 domain.
- BBC0906 reduced ROS production and suppressed catabolic factor expression in chondrocytes.
- Intra-articular injection of BBC0906 in an OA mouse model attenuated cartilage degradation and alleviated OA symptoms.
Conclusions:
- Selective inhibition of BET protein BD2 is a viable therapeutic strategy for osteoarthritis.
- BBC0906 effectively targets oxidative stress and cartilage degradation pathways implicated in OA.
- BBC0906 shows promise as a safe and effective treatment for osteoarthritis.
