Pharmacological targeting of KDM6A and KDM6B, as a novel therapeutic strategy for treating craniosynostosis in Saethre-Chotzen syndrome

Clara Pribadi, Esther Camp, Dimitrios Cakouros, Peter Anderson, Carlotta Glackin, Stan Gronthos

Research output: Contribution to journalArticlepeer-review

Abstract

Background: During development, excessive osteogenic differentiation of mesenchymal progenitor cells (MPC) within the cranial sutures can lead to premature suture fusion or craniosynostosis, leading to craniofacial and cognitive issues. Saethre-Chotzen syndrome (SCS) is a common form of craniosynostosis, caused by TWIST-1 gene mutations. Currently, the only treatment option for craniosynostosis involves multiple invasive cranial surgeries, which can lead to serious complications. Methods: The present study utilized Twist-1 haploinsufficient (Twist-1del/+) mice as SCS mouse model to investigate the inhibition of Kdm6a and Kdm6b activity using the pharmacological inhibitor, GSK-J4, on calvarial cell osteogenic potential. Results: This study showed that the histone methyltransferase EZH2, an osteogenesis inhibitor, is downregulated in calvarial cells derived from Twist-1del/+ mice, whereas the counter histone demethylases, Kdm6a and Kdm6b, known promoters of osteogenesis, were upregulated. In vitro studies confirmed that siRNA-mediated inhibition of Kdm6a and Kdm6b expression suppressed osteogenic differentiation of Twist-1del/+ calvarial cells. Moreover, pharmacological targeting of Kdm6a and Kdm6b activity, with the inhibitor, GSK-J4, caused a dose-dependent suppression of osteogenic differentiation by Twist-1del/+ calvarial cells in vitro and reduced mineralized bone formation in Twist-1del/+ calvarial explant cultures. Chromatin immunoprecipitation and Western blot analyses found that GSK-J4 treatment elevated the levels of the Kdm6a and Kdm6b epigenetic target, the repressive mark of tri-methylated lysine 27 on histone 3, on osteogenic genes leading to repression of Runx2 and Alkaline Phosphatase expression. Pre-clinical in vivo studies showed that local administration of GSK-J4 to the calvaria of Twist-1del/+ mice prevented premature suture fusion and kept the sutures open up to postnatal day 20. Conclusion: The inhibition of Kdm6a and Kdm6b activity by GSK-J4 could be used as a potential non-invasive therapeutic strategy for preventing craniosynostosis in children with SCS. Graphical abstract: Pharmacological targeting of Kdm6a/b activity can alleviate craniosynostosis in Saethre-Chotzen syndrome. Aberrant osteogenesis by Twist-1 mutant cranial suture mesenchymal progenitor cells occurs via deregulation of epigenetic modifiers Ezh2 and Kdm6a/Kdm6b. Suppression of Kdm6a- and Kdm6b-mediated osteogenesis with GSK-J4 inhibitor can prevent prefusion of cranial sutures.[Figure not available: see fulltext.].

Original languageEnglish
Article number529
JournalStem Cell Research and Therapy
Volume11
Issue number1
DOIs
Publication statusPublished or Issued - Dec 2020

Keywords

  • Calvarial cells
  • Coronal sutures
  • Craniosynostosis
  • Epigenetics
  • KDM6A
  • KDM6B
  • Osteogenesis
  • Saethre-Chotzen syndrome
  • TWIST-1
  • Twist-1 mice

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Molecular Medicine
  • Biochemistry, Genetics and Molecular Biology (miscellaneous)
  • Cell Biology

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