Melatonin regulates human bone sialoprotein gene transcription

J Oral Sci. 2014 Mar;56(1):67-76. doi: 10.2334/josnusd.56.67.

Abstract

Melatonin is produced by the pineal gland and regulates various physiological processes including osteoblast differentiation and bone formation. Bone sialoprotein (BSP) is a mineralized connective tissue-specific protein expressed in the early stage of cementum and bone mineralization. To elucidate the effects of melatonin on human BSP gene expression, we utilized human Saos2 osteoblast-like cells. Melatonin (100 nM) increased the level of BSP mRNA at 3 h, and the level became maximal at 12 and 24 h. We then investigated the melatonin-induced transcriptional activity of luciferase constructs (between -84LUC and -868LUC) including different lengths of the human BSP gene promoter transfected into Saos2 cells. The effects of melatonin abrogated in constructs included 2-bp mutations in the two cAMP response elements (CRE1 and CRE2). The effects of melatonin were suppressed by protein kinase A, tyrosine kinase, ERK1/2 and phosphatidylinositol 3-kinase inhibitors. Gel mobility shift assays showed that melatonin increased the binding of nuclear proteins to CRE1 and CRE2, and antibodies against CRE binding protein 1 (CREB1), phospho-CREB1, c-Fos, c-Jun, JunD and Fra2 disrupted CRE1 and CRE2 protein complex formation. These data indicate that melatonin induces BSP transcription via the CRE1 and CRE2 elements in the human BSP gene promoter. (J Oral Sci 56, 67-76, 2014).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line, Tumor
  • Chromatin Immunoprecipitation
  • Core Binding Factor Alpha 1 Subunit / metabolism
  • Humans
  • Integrin-Binding Sialoprotein / genetics*
  • Melatonin / physiology*
  • Promoter Regions, Genetic
  • RNA, Messenger / genetics
  • Sp7 Transcription Factor
  • Transcription Factors / metabolism
  • Transcription, Genetic / physiology*

Substances

  • Core Binding Factor Alpha 1 Subunit
  • Integrin-Binding Sialoprotein
  • RNA, Messenger
  • RUNX2 protein, human
  • Sp7 Transcription Factor
  • SP7 protein, human
  • Transcription Factors
  • Melatonin