Stimulatory effect of zinc-chelating dipeptide on deoxyribonucleic acid synthesis in osteoblastic MC3T3-E1 cells.
Whether deoxyribonucleic acid (DNA) synthesis in osteoblastic MC3T3-E1 cells is stimulated by zinc, an activator of bone formation, was investigated in vitro. After subculture for 3 days, the cells were cultured for up to 3 days (72 h) with zinc sulfate or zinc-chelated dipeptide (beta-alanyl-L-histidinato zinc; AHZ) in the range of 10(-7) to 10(-5) M. The culture with zinc compounds (10(-5) M) produced a significant increase of cell number, DNA content, and protein concentration in the cells, as reported previously. The culture with zinc compounds (10(-6) and 10(-5) M) clearly stimulated DNA synthesis in the homogenate, when it was estimated by the incorporation of [3H]deoxythymidine 5'-triphosphate into the DNA in the homogenate of cells. The AHZ effect was greater than that of zinc sulfate. The culture together with cycloheximide (19(-6) M) completely abolished the zinc compounds (10(-5) M)-induced increase of DNA synthesis in the cells, suggesting that the zinc compound effect is based on a newly synthesized protein component. Moreover, when zinc sulfate (10(-7) and 10(-6) M) or AHZ (10(-8) to 10(-5) M) was added into the reaction mixture with the homogenate of cells cultured without zinc compounds, the DNA synthesis was clearly increased. The effect of addition of zinc compounds (10(-6) M) on the DNA synthesis was completely inhibited by the presence of staurosporine (10(-8) M), an inhibitor of protein kinase C, or okadaic acid (10(-7) M), an inhibitor of protein phosphatase. The present study demonstrates that zinc compounds have a stimulatory effect on DNA synthesis in osteoblastic cells.
Yamaguchi
M
M
Laboratory of Endocrinology and Molecular Metabolism, Graduate School of Nutritional Sciences, University of Shizuoka, Japan.
Matsui
T
T
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002614:Chelating Agents / Q000494:pharmacology*; D004261:DNA Replication / Q000187:drug effects*; D004151:Dipeptides / Q000494:pharmacology*; D051379:Mice; D009942:Organometallic Compounds / Q000494:pharmacology*; D010006:Osteoblasts / Q000166:cytology*
D002614:Chelating Agents; D004151:Dipeptides; D009942:Organometallic Compounds; C089030:di(N-acetylalanyl-histidinato)zinc