Phase-Dependent effects of transforming growth factor beta 1 on osteoblastic markers of human osteoblastic cell line sV-HFO during mineralization.
A human osteoblastic cell line (SV-HFO) established in our laboratory expresses osteoblastic markers, including mineralization in vitro, in response to differentiation-inducing agents such as dexamethasone. In this study, we examined the effects of transforming growth factor beta 1 (TGF-beta 1) on the mineralization of SV-HFO cells and show that TGF-beta 1 inhibited the mineralization of the cells via down regulation of tetranectin and alkaline phosphatase without influencing other osteoblastic markers. To examine precisely the effects of TGF-beta 1 on the process of mineralization, we tentatively divided the whole process of mineralization into four phases: induced ALP activity (days 0-5), maximal ALP activity (days 5-10), early mineralization (days 10-15), and progressive mineralization (days 15-20). These inhibitory effects of TGF-beta 1 on the expression of tetranectin and alkaline phosphatase, like that on mineralization, were observed only when TGF-beta 1 was applied in the early phase of the process of mineralization. On the other hand, the other osteoblastic markers were not influenced by treatment with TGF-beta 1. These results suggest that TGF-beta 1 may inhibit mineralization of osteoblasts by the downregulation of tetranectin and alkaline phosphatase expression in the early phase. Thus, TGF-beta 1 has phase-dependent effects on a human osteoblastic cell line during the process of mineralization.
Department of Pathology, Sapporo Medical University School of Medicine, Japan.
K
K
Iba
N
N
Sawada
S
S
Nuka
H
H
Chiba
H
H
Obata
H
H
Isomura
M
M
Satoh
S
S
Ishii
M
M
Mori
D000469:Alkaline Phosphatase / Q000096:biosynthesis / Q000235:genetics; D014408:Biomarkers, Tumor / Q000096:biosynthesis* / Q000235:genetics; D001798:Blood Proteins / Q000096:biosynthesis / Q000235:genetics; D015152:Blotting, Northern; D015153:Blotting, Western; D002113:Calcification, Physiologic / Q000187:drug effects / Q000502:physiology; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D002478:Cells, Cultured; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics; D006801:Humans; D037181:Lectins, C-Type; D008970:Molecular Weight; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D015675:Osteocalcin / Q000096:biosynthesis; D015676:Osteonectin / Q000096:biosynthesis; D053495:Osteopontin; D010758:Phosphorus / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012795:Sialoglycoproteins / Q000096:biosynthesis; D014158:Transcription, Genetic / Q000187:drug effects / Q000235:genetics; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
D014408:Biomarkers, Tumor; D001798:Blood Proteins; D037181:Lectins, C-Type; D015676:Osteonectin; D012333:RNA, Messenger; C506895:SPP1 protein, human; D012795:Sialoglycoproteins; D016212:Transforming Growth Factor beta; D015675:Osteocalcin; D053495:Osteopontin; C048648:tetranectin; D010758:Phosphorus; D000469:Alkaline Phosphatase; D002118:Calcium