Type I collagen-induced osteoblastic differentiation of bone-marrow cells mediated by collagen-alpha2beta1 integrin interaction.
Bone marrow cells are multipotent cells. When bone marrow cells were cultured with type I collagen matrix gels, they showed high alkaline phosphatase activity, collagen synthesis, and formed mineralized tissues. Furthermore, cells expressed osteocalcin and bone sialoprotein genes, which are osteoblast-specific genes. These findings indicate that type I collagen matrix gels induce osteoblastic differentiation of bone marrow cells. Type I collagen interacts with the alpha 2 beta 1 integrin receptor on the cell membrane and mediates extracellular signals into cells. DGEA peptide is a cell-binding domain of type I collagen molecule. When collagen-integrin interaction was interrupted by the addition of Asp-Gly-Glu-Ala (DGEA) peptide to the culture, the expression of osteoblastic phenotypes of bone marrow cells was inhibited. Furthermore, anti-alpha 2 integrin antibody, which interacts with alpha subunit of integrin and blocks the binding of integrin with collagen, suppressed the expression of osteoblastic phenotypes. These findings imply that collagen-alpha 2 beta 1 integrin interaction is an important signal for the osteoblastic differentiation of bone marrow cells.
Mizuno
M
M
Department of Biochemistry, School of Dentistry, Hokkaido University, Sapporo, Japan.
Fujisawa
R
R
Kuboki
Y
Y
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001854:Bone Marrow Cells / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D003094:Collagen / Q000378:metabolism / Q000494:pharmacology*; D016023:Integrins / Q000187:drug effects* / Q000378:metabolism; D010006:Osteoblasts / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D015675:Osteocalcin / Q000096:biosynthesis / Q000235:genetics; D053495:Osteopontin; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D038981:Receptors, Collagen; D012795:Sialoglycoproteins / Q000096:biosynthesis / Q000235:genetics
D016023:Integrins; D012333:RNA, Messenger; D038981:Receptors, Collagen; D012795:Sialoglycoproteins; C506897:Spp1 protein, rat; D015675:Osteocalcin; D053495:Osteopontin; D003094:Collagen; D000469:Alkaline Phosphatase