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Published on: June 27, 2025
H3K27me3 demethylases regulate in vitro chondrogenesis and chondrocyte activity in osteoarthritis
Clarence Yapp1,2, Andrew J Carr1, Andrew Price1
1Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Botnar Research Centre, University of Oxford, Nuffield Orthopaedic Centre, Windmill Road, Headington, OX3 7LD, Oxford, UK.
Background:
Epigenetic changes (i.e., chromatin modifications) occur during chondrogenesis and in osteoarthritis (OA). We investigated the effect of H3K27me3 demethylase inhibition on chondrogenesis and assessed its utility in cartilage tissue engineering and in understanding cartilage destruction in OA.
Methods:
We used a high-content screen to assess the effect of epigenetic modifying compounds on collagen output during chondrogenesis of monolayer human mesenchymal stem cells (MSCs). The impact of GSK-J4 on gene expression, glycosaminoglycan output and collagen formation during differentiation of MSCs into cartilage discs was investigated. Expression of lysine (K)-specific demethylase 6A (UTX) and Jumonji domain-containing 3 (JMJD3), the HEK27Me3 demethylases targeted by GSK-J4, was measured in damaged and undamaged cartilage from patients with OA. The impact of GSK-J4 on ex vivo cartilage destruction and expression of OA-related genes in human articular chondrocytes (HACs) was assessed. H3K27Me3 demethylase regulation of transforming growth factor (TGF)-β-induced gene expression was measured in MSCs and HACs.
Results:
Treatment of chondrogenic MSCs with the H3K27me3 demethylase inhibitor GSK-J4, which targets JMJD3 and UTX, inhibited collagen output; expression of chondrogenic genes, including SOX9 and COL2A1; and disrupted glycosaminoglycan and collagen synthesis. JMJD3 but not UTX expression was increased during chondrogenesis and in damaged OA cartilage, suggesting a predominant role of JMJD3 in chondrogenesis and OA. GSK-J4 prevented ex vivo cartilage destruction and expression of the OA-related genes MMP13 and PTGS2. TGF-β is a key regulator of chondrogenesis and articular cartilage homeostasis, and TGF-β-induced gene expression was inhibited by GSK-J4 treatment of both chondrogenic MSCs and HACs.
Conclusions:
Overall, we show that H3K27me3 demethylases modulate chondrogenesis and that enhancing this activity may improve production of tissue-engineered cartilage. In contrast, targeted inhibition of H3K27me3 demethylases could provide a novel approach in OA therapeutics.
Insights
Inhibiting H3K27me3 demethylases with GSK-J4 impacts cartilage formation and osteoarthritis progression. This suggests potential for tissue engineering and new osteoarthritis treatments.
Area of Science:
- Epigenetics
- Cartilage Biology
- Osteoarthritis Research
Background:
- Epigenetic modifications, specifically chromatin changes, are integral to chondrogenesis and the pathogenesis of osteoarthritis (OA).
- Understanding the role of epigenetic regulators in cartilage homeostasis is crucial for developing therapeutic strategies.
Purpose of the Study:
- To investigate the impact of H3K27me3 demethylase inhibition on chondrogenesis.
- To evaluate the potential of targeting these demethylases in cartilage tissue engineering and OA treatment.
- To explore the role of specific demethylases (JMJD3 and UTX) in OA cartilage destruction.
Main Methods:
- High-content screening of epigenetic modifying compounds for collagen output during mesenchymal stem cell (MSC) chondrogenesis.
- Assessing the effects of GSK-J4 on gene expression, glycosaminoglycan, and collagen synthesis in differentiating MSCs.
- Measuring JMJD3 and UTX expression in OA cartilage and evaluating GSK-J4's impact on ex vivo cartilage destruction and OA-related gene expression in human articular chondrocytes (HACs).
Main Results:
- GSK-J4 treatment inhibited collagen production, chondrogenic gene expression (SOX9, COL2A1), and glycosaminoglycan synthesis in MSCs.
- JMJD3 expression was upregulated during chondrogenesis and in OA cartilage, indicating its significant role.
- GSK-J4 treatment prevented ex vivo cartilage destruction and suppressed OA-related genes (MMP13, PTGS2), while also inhibiting TGF-β-induced gene expression.
Conclusions:
- H3K27me3 demethylases play a critical role in modulating chondrogenesis.
- Enhancing H3K27me3 demethylase activity may improve cartilage tissue engineering outcomes.
- Targeted inhibition of H3K27me3 demethylases presents a promising therapeutic avenue for osteoarthritis.
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