Expression of mRNA of murine bone-related proteins in ectopic bone induced by murine bone morphogenetic protein-4.
To determine whether a system of ectopic bone formation induced by osteosarcoma-derived bone-inducing substance (bone morphogenetic protein-4) can be used as a model of developing bone at the molecular level, we studied the expression of bone-related protein mRNAs in the process of ectopic bone formation using non-radioisotopic in situ hybridization. Osteonectin mRNA was detected in fibroblast-like cells, which are similar to periosteal cells from the early to middle stages of bone development. The proportion of osteonectin mRNA-expressing cells was greater than that of osteopontin mRNA-expressing cells in hypertrophic chondrocytes and osteoblast-like cells. In contrast, osteopontin mRNA was localized in a limited population of hypertrophic chondrocytes, a single layer of osteoblast-like cells adjacent to the bone trabeculae in the middle stage of bone formation, and in a limited subset of osteocytes in the late stage. A strong osteocalcin mRNA signal was detected in osteoblast-like cells from the middle to late stages and in a limited subset of osteocytes in the late stage of bone development. Since the sequential gene expression pattern of bone-related proteins in the present system is comparable to that in embryonic osteogenesis, this system may be useful as a model for studying gene expression in osteogenesis.
Hirota
S
S
Department of Pathology, Osaka University Medical School, Suita, Japan.
Takaoka
K
K
Hashimoto
J
J
Nakase
T
T
Takemura
T
T
Morii
E
E
Fukuyama
A
A
Morihana
K
K
Kitamura
Y
Y
Nomura
S
S
D000818:Animals; D001847:Bone Diseases / Q000378:metabolism*; D019485:Bone Morphogenetic Proteins; D001842:Bone and Bones / Q000378:metabolism*; D002828:Choristoma / Q000378:metabolism*; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D015870:Gene Expression; D006133:Growth Substances / Q000494:pharmacology*; D051379:Mice; D008813:Mice, Inbred ICR; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D010011:Osteocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D015676:Osteonectin / Q000096:biosynthesis*; D053495:Osteopontin; D010750:Phosphoproteins / Q000096:biosynthesis; D011506:Proteins / Q000494:pharmacology*; D012333:RNA, Messenger / Q000096:biosynthesis*; D012795:Sialoglycoproteins / Q000096:biosynthesis*
D019485:Bone Morphogenetic Proteins; D006133:Growth Substances; D015676:Osteonectin; D010750:Phosphoproteins; D011506:Proteins; D012333:RNA, Messenger; D012795:Sialoglycoproteins; C506896:Spp1 protein, mouse; D053495:Osteopontin