title: H3K27me3 demethylases regulate in vitro chondrogenesis and chondrocyte activity in osteoarthritis.
abstract: 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.
  
  
  
  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.
  
  
  
  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.
  
  
  
  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.
authors.affiliation: Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Botnar Research Centre, University of Oxford, Nuffield Orthopaedic Centre, Windmill Road, Headington, OX3 7LD, Oxford, UK.|Structural Genomics Consortium, University of Oxford, Oxford, UK.
authors.forename: Clarence
authors.initials: C
authors.lastname: Yapp
authors.affiliation: Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Botnar Research Centre, University of Oxford, Nuffield Orthopaedic Centre, Windmill Road, Headington, OX3 7LD, Oxford, UK.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Carr
authors.affiliation: Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Botnar Research Centre, University of Oxford, Nuffield Orthopaedic Centre, Windmill Road, Headington, OX3 7LD, Oxford, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Price
authors.affiliation: Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Botnar Research Centre, University of Oxford, Nuffield Orthopaedic Centre, Windmill Road, Headington, OX3 7LD, Oxford, UK.|Structural Genomics Consortium, University of Oxford, Oxford, UK.|Oxford Stem Cell Institute, Oxford, UK.
authors.forename: Udo
authors.initials: U
authors.lastname: Oppermann
authors.affiliation: Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Botnar Research Centre, University of Oxford, Nuffield Orthopaedic Centre, Windmill Road, Headington, OX3 7LD, Oxford, UK. sarah.snelling@ndorms.ox.ac.uk.
authors.forename: Sarah J B
authors.initials: SJ
authors.lastname: Snelling
mesh_terms: D001552:Benzazepines / Q000494:pharmacology; D002358:Cartilage, Articular / Q000187:drug effects / Q000201:enzymology; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D019902:Chondrocytes / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D020219:Chondrogenesis / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D055785:Gene Knockdown Techniques; D006801:Humans; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D056484:Jumonji Domain-Containing Histone Demethylases / Q000378:metabolism*; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D010003:Osteoarthritis / Q000201:enzymology / Q000473:pathology*; D011743:Pyrimidines / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016212:Transforming Growth Factor beta / Q000378:metabolism
chemical_list: D001552:Benzazepines; D004791:Enzyme Inhibitors; C000593030:GSK-J4; D011743:Pyrimidines; D016212:Transforming Growth Factor beta; D056484:Jumonji Domain-Containing Histone Demethylases
keywords: Epigenetics; Histone demethylase; JMJD3; Osteoarthritis; TGF-β