Yamaguchi M, Matsui T
Laboratory of Endocrinology and Molecular Metabolism, Graduate School of Nutritional Sciences, University of Shizuoka, Japan.
Peptides. 1996;17(7):1207-11. doi: 10.1016/s0196-9781(96)00114-3.
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.
在体外研究了成骨细胞MC3T3-E1细胞中的脱氧核糖核酸（DNA）合成是否受锌（一种骨形成激活剂）的刺激。传代培养3天后，将细胞与浓度范围为10⁻⁷至10⁻⁵ M的硫酸锌或锌螯合二肽（β-丙氨酰-L-组氨酸锌；AHZ）一起培养长达3天（72小时）。如先前报道，用锌化合物（10⁻⁵ M）培养可使细胞数量、DNA含量和蛋白质浓度显著增加。当通过将[³H]脱氧胸苷5'-三磷酸掺入细胞匀浆中的DNA来估算时，用锌化合物（10⁻⁶和10⁻⁵ M）培养能明显刺激匀浆中的DNA合成。AHZ的作用大于硫酸锌。与放线菌酮（10⁻⁶ M）共同培养完全消除了锌化合物（10⁻⁵ M）诱导的细胞中DNA合成的增加，这表明锌化合物的作用基于一种新合成的蛋白质成分。此外，当将硫酸锌（10⁻⁷和10⁻⁶ M）或AHZ（10⁻⁸至10⁻⁵ M）添加到不含锌化合物培养的细胞匀浆的反应混合物中时，DNA合成明显增加。添加锌化合物（10⁻⁶ M）对DNA合成的作用被蛋白激酶C抑制剂星形孢菌素（10⁻⁸ M）或蛋白磷酸酶抑制剂冈田酸（10⁻⁷ M）完全抑制。本研究表明锌化合物对成骨细胞中的DNA合成具有刺激作用。
