Carboxyl-terminal parathyroid hormone fragments stimulate type-1 procollagen and insulin-like growth factor-binding protein-5 mRNA expression in osteoblastic UMR-106 cells.
The effects of carboxyl-terminal (C-) PTH fragments, (35-84), (53-84) and (69-84), on the proliferation and function of osteoblastic UMR-106 cells were compared with those of amino-terminal (N-) (1-34) and intact (I-) (1-84) PTH. I-PTH as well as N-PTH at 10(-8)M significantly inhibited [3H] thymidine incorporation and stimulated alkaline phosphatase activity in UMR-106 cells. No C-PTH fragments affected them. In contrast, the expression of type-1 procollagen mRNA in these cells was stimulated by all C-PTH fragments, inhibited by N-PTH and not affected by I-PTH. All C-PTH fragments except (69-84) as well as N-PTH and I-PTH stimulated IGFBP-5 mRNA expression. The present study suggests that the C-portion of the PTH molecule exercises biological activities in mRNA expression of type-1 procollagen as well as IGFBP-5 in osteoblasts, and that it might be involved in the anabolic action of PTH on bone in vivo.
Department of Medicine, Kobe University School of Medicine, Japan.
M
M
Nasu
T
T
Sugimoto
H
H
Kaji
J
J
Kano
K
K
Chihara
D002460:Cell Line; D015870:Gene Expression / Q000187:drug effects*; D018975:Insulin-Like Growth Factor Binding Protein 5 / Q000235:genetics*; D010006:Osteoblasts / Q000187:drug effects / Q000378:metabolism*; D010281:Parathyroid Hormone / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology*; D011347:Procollagen / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D019379:Teriparatide / Q000494:pharmacology
D018975:Insulin-Like Growth Factor Binding Protein 5; D010281:Parathyroid Hormone; D010446:Peptide Fragments; D011347:Procollagen; D012333:RNA, Messenger; D019379:Teriparatide