Expression of the PEBP2alphaA/AML3/CBFA1 gene is regulated by BMP4/7 heterodimer and its overexpression suppresses type I collagen and osteocalcin gene expression in osteoblastic and nonosteoblastic mesenchymal cells

Bone. 1998 Feb;22(2):87-92. doi: 10.1016/s8756-3282(97)00267-6.

Abstract

PEBP2alphaA/AML3/CBFA1 is one of the transcription regulators that belong to the PEBP2/AML family. The knockout mice, where the gene encoding PEBP2alphaA/AML3/CBFA1 was inactivated, showed no osteogenesis, indicating the critical role of this transcription factor in osteoblastic differentiation (Komori, Y. et al. Cell 89:755-764; 1997). The aim of this study is to examine the regulation of PEBP2alphaA/AML3/CBFA1 expression in skeletal (MC3T3E1, ROS17/2.8) and nonskeletal (C3H10T1/2, C2C12, NIH3T3) cell lines. The basal levels of PEBP2alphaA/AML3/CBFA1 were time dependent and were increased during culture in ROS17/2.8 by day 2, remaining similar during cultures in other types of cells. Treatment with a 100-ng/mL BMP4/7 heterodimer enhanced the expression of PEBP2alphaA/AML3/CBFA1 mRNA levels in MC3T3E1 and C2C12 cells, whereas BMP2 did not significantly alter PEBP2alphaA/AML3/CBFA1 mRNA levels in both skeletal and nonskeletal cells. The PEBP2alphaA/AML3/CBFA1 mRNA level in ROS17/2.8 cells was relatively high on day 2, and was not further enhanced by treatment with BMP4/7. In contrast to the reported type I collagen gene upregulation by the overexpression of Osf2/CBFA1, which differs from PEBP2alphaA/AML3/CBFA1 by containing a unique 87 amino acid sequence at its amino terminal end, overexpression of PEBP2alphaA/AML3/CBFA1 suppressed type I collagen mRNA levels in MC3T3E1, C2C12, and C3H10T1/2 cells and suppressed osteocalcin mRNA levels in ROS17/2.8 cells. The osteopontin mRNA level was enhanced by overexpression of PEBP2alphaA/AML3/CBFA1 in MC3T3E1, while the level was similar in ROS17/2.8 cells and was suppressed in C2C12 cells. These data indicate that PEBP2alphaA/AML3/CBFA1 is one of the targets of BMP4/7 and participates in the regulation of the expression of genes related to osteoblast phenotype. The overexpression study suggests that PEBP2alphaA/AML3/CBFA1 and Osf2/CBFA1 may have a different function in the regulation of the expression of the genes related to the osteoblast phenotype.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3T3 Cells
  • Animals
  • Blotting, Northern
  • Bone Morphogenetic Protein 4
  • Bone Morphogenetic Protein 7
  • Bone Morphogenetic Proteins / genetics*
  • Bone Morphogenetic Proteins / pharmacology*
  • Collagen / genetics*
  • Core Binding Factor Alpha 1 Subunit
  • DNA-Binding Proteins / biosynthesis
  • DNA-Binding Proteins / genetics*
  • Gene Expression Regulation / drug effects
  • Mesoderm / metabolism
  • Mice
  • Neoplasm Proteins*
  • Osteoblasts / metabolism
  • Osteocalcin / genetics*
  • Osteopontin
  • Phenotype
  • RNA, Messenger / genetics
  • Sialoglycoproteins / genetics
  • Transcription Factor AP-2
  • Transcription Factors / biosynthesis
  • Transcription Factors / genetics*
  • Transforming Growth Factor beta / pharmacology

Substances

  • Bmp4 protein, mouse
  • Bone Morphogenetic Protein 4
  • Bone Morphogenetic Protein 7
  • Bone Morphogenetic Proteins
  • Core Binding Factor Alpha 1 Subunit
  • DNA-Binding Proteins
  • Neoplasm Proteins
  • RNA, Messenger
  • Runx2 protein, mouse
  • Sialoglycoproteins
  • Spp1 protein, mouse
  • Transcription Factor AP-2
  • Transcription Factors
  • Transforming Growth Factor beta
  • Osteocalcin
  • Osteopontin
  • Collagen