Jagged1 promotes mineralization in human bone-derived cells.

OBJECTIVES: The present study aimed to investigate the expression of Notch signaling components during osteogenic differentiation in vitro and bone healing in vivo. In addition, the influence of Notch signaling on osteogenic differentiation of human bone-derived cells was examined.

METHODS: Gene expression profiling of osteogenic differentiation of human bone marrow-derived mesenchymal stromal cells in vitro (GSE80614) and bone healing period of murine tibial fracture in vivo (GSE99388) was downloaded from Gene Expression Omnibus database. The expression of Notch signaling components was obtained from bioinformatic tools. Human bone-derived cells were isolated from alveolar and iliac bone. Cells were seeded on Jagged1 immobilized surface. Osteogenic marker gene expression and mineralization were examined using real-time polymerase chain reaction and alizarin red s staining, respectively.

RESULTS: From bioinformatic analysis of gene expression profiling, various Notch signaling components were differentially expressed during osteogenic differentiation of human bone marrow-derived mesenchymal stromal cells in vitro and bone healing period of murine tibial fracture in vivo. The common genes differentially regulated of these two datasets were Hes1, Aph1a, Nsctn, Furin, Adam17, Hey1, Pcsk5, Nedd4, Jag1, Heyl, Notch3, Dlk1, and Hey2. For an in vitro analysis, the mineral deposition markedly increased after seeding human bone-derived cells on Jagged1 immobilized surface, correspondingly with the increase of ALP mRNA expression. Jagged1 treatment downregulated TWIST2 mRNA expression in both human alveolar and iliac bone-derived cells.

CONCLUSION: Notch signaling is regulated during osteogenic differentiation and bone healing. In addition, the activation of Notch signaling promotes osteogenic differentiation in human alveolar and iliac bone-derived cells. Therefore, Notch signaling manipulation could be a useful approach for enhancing bone regeneration.