Osteoblast-related gene expression of bone marrow cells during the osteoblastic differentiation induced by type I collagen.
Bone marrow contains multipotent cells that differentiate into fibroblasts, adipocytes, and osteoblasts. Recently we found that type I collagen matrix induced the osteoblastic differentiation of bone marrow cells. Three weeks after cells were cultured with type I collagen, they formed mineralized tissues. In this study, we investigated the expression of osteoblast-related genes (alkaline phosphatase, osteocalcin, bone sialoprotein, osteopontin, and cbfa-1) during the osteoblastic differentiation. The expression of alkaline phosphatase and osteopontin genes increased time-dependently during the osteoblastic differentiation. Osteocalcin and bone sialoprotein genes were expressed in cells that formed mineralized tissues, and both were expressed only after cells reached the mineralized tissue-formation stage. On the other hand, the cbfa-1 gene was expressed from the early differentiation stage. The Asp-Gly-Glu-Ala (DGEA) amino acid domain of type I collagen interacts with the alpha2beta1 integrin receptor on the cell membrane and mediates extracellular signals into cells. When the collagen-integrin interaction was interrupted by the addition of DGEA peptide to the culture, the expression of osteoblastic phenotypes of bone marrow cells was inhibited. These findings imply that the collagen-alpha2beta1 integrin interaction is an important signal for the osteoblastic differentiation of bone marrow cells.
Mizuno
M
M
Department of Oral Health Science, School of Dentistry, Hokkaido University, 060-8586 Sapporo. mmizuno@den.hokudai.ac.jp
Kuboki
Y
Y
D020816:Amino Acid Motifs / Q000502:physiology; D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D002454:Cell Differentiation / Q000187:drug effects* / Q000235:genetics; D002478:Cells, Cultured; D003094:Collagen / Q000737:chemistry / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects*; D016023:Integrins / Q000502:physiology; D009363:Neoplasm Proteins; D010006:Osteoblasts / Q000502:physiology; D051381:Rats; D038981:Receptors, Collagen; D014157:Transcription Factors / Q000235:genetics* / Q000502:physiology
D016023:Integrins; D009363:Neoplasm Proteins; D038981:Receptors, Collagen; D014157:Transcription Factors; D003094:Collagen