title: Identification of endoglin-dependent BMP-2-induced genes in the murine periodontal ligament cell line PDL-L2.
abstract: BACKGROUND
  The periodontal ligament (PDL), connective tissue located between the cementum of teeth and alveolar bone of the mandibula, plays an important role in the maintenance and regeneration of periodontal tissues. We reported previously that endoglin was involved in the BMP-2-induced osteogenic differentiation of mouse PDL cells, which is associated with Smad-2 phosphorylation but not Smad-1/5/8 phosphorylation. In this study, to elucidate the detailed mechanism underlying the BMP-2 signalling pathway unique to PDL cells, we performed a microarray analysis to identify BMP-2-inducible genes in PDL-L2 cells, a mouse PDL-derived cell line, with or without endoglin knockdown.
  
  
  RESULTS
  Sixty-four genes were upregulated more than twofold by BMP-2 in PDL-L2 cells. Of these genes, 11 were endoglin-dependent, including Id4, which encodes ID4, a helix-loop-helix transcription factor closely associated with TGF-β signaling and osteoblast differentiation. The endoglin-dependent induction of ID4 by BMP-2 was also verified at a protein level.
  
  
  CONCLUSIONS
  Our findings indicate that ID4 could be a signal mediator involved in the BMP-2-induced endoglin-dependent osteogenic differentiation of PDL cells.
authors.affiliation: Laboratory of Biological Macromolecules, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai 599-8531, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Ishibashi
authors.affiliation: Laboratory of Biological Macromolecules, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai 599-8531, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Inui
keywords: Bone morphogenetic protein; Endoglin; Periodontal ligament