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Trichostatin A activates the osteopontin gene promoter through AP1 site

Ryosuke Sakata1, Shinji Minami, Yoshihiro Sowa

  • 1Department of Orthopedic Surgery, Wakayama Medical University, 811-1, Wakayama 641-8510, Japan. ryosuke@wakayama-med.ac.jp

Biochemical and Biophysical Research Communications
|February 27, 2004
PubMed

Insights

Trichostatin A (TSA), a histone deacetylase inhibitor, promotes osteoblast differentiation. TSA upregulates osteopontin (OPN) expression by activating the AP1 transcription factor, crucial for this process.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Biochemistry

Background:

  • Osteoblastic differentiation is a complex process involving gene expression regulation.
  • Histone deacetylase inhibitors, like trichostatin A (TSA), are known to influence cellular differentiation pathways.

Purpose of the Study:

  • To investigate the effect of TSA on osteoblastic differentiation.
  • To elucidate the molecular mechanisms underlying TSA-induced osteopontin (OPN) expression.

Main Methods:

  • Utilized a mouse undifferentiated mesenchymal cell line.
  • Assessed OPN mRNA and protein levels following TSA treatment.
  • Performed promoter deletion analysis and luciferase assays.
  • Conducted electrophoretic mobility shift assays (EMSA) with specific antibodies.

Main Results:

  • TSA significantly increased OPN mRNA and protein levels.
  • TSA-induced OPN expression was regulated by a specific region (-75 to -65) of the OPN promoter containing an AP1-binding site.
  • EMSA confirmed that AP1, specifically c-Fos and phosphorylated c-Jun, is involved in TSA-induced OPN expression.

Conclusions:

  • AP1 transcription factor plays a critical role in mediating TSA-induced osteopontin expression during osteoblastic differentiation.
  • TSA promotes osteoblastic differentiation through the AP1-mediated upregulation of OPN.

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