Division of Toxicology, Department of Pharmacology, The University of Texas Medical School at Houston, PO Box 20708, 77025, Houston, Texas.
Biol Trace Elem Res. 1982 Dec;4(4):289-301. doi: 10.1007/BF02786543.
The effects of serum components and amino acids on the uptake and cytotoxicity of NiCl2 were examined in cultured Chinese hamster ovary (CHO) cells. CHO cells maintained in a minimal salts/glucose medium accumulated 10-fold more(63)Ni than did cells maintained in complete medium supplemented with 10% fetal bovine serum. Cell-surface binding of(63)Ni appeared to account for the majority of this increased accumulation of cell-associated nickel observed in the simple maintenance medium since such increases were reduced 70% by trypsin treatment. The addition of the Ni(2+)-binding amino acids cysteine or histidine to the salts/glucose medium markedly decreased(63)Ni accumulations, an effect not observed following addition of any of several amino acids that do not bind Ni(2+). Supplementation of the salts/glucose medium with fetal bovine serum decreased in a concentration dependent fashion both the(63)Ni(2+) uptake and cell detachment caused by Ni(2+), while dialyzed (amino acid-free) serum was 3-5-fold less effective than undialyzed serum at reducing(63)Ni(2+) uptake and similarly exhibited only a slight protective effect against nickel-induced cytotoxicity. Supplementation of dialyzed serum with cysteine at levels approximating those in whole serum partially restored its inhibitory activity toward nickel uptake by cells and restored completely its inhibition of nickel's cytotoxicity, indicating the predominant role of specific amino acids over serum proteins in regulating the uptake and subsequent cytotoxicity of Ni(2+). Addition of cysteine to the salts/glucose medium during a 2 h exposure of cells to either 100 μM HgCl2 or 1 mM NiCl2 masked the cytotoxic effects of these metal ions. These results demonstrate the importance of extracellular small molecular weight metal ion chelators in altering the biological effects of metal ions at the level of metal uptake.
研究了血清成分和氨基酸对氯化镍摄取和细胞毒性的影响，在培养的中国仓鼠卵巢（CHO）细胞中进行。CHO 细胞在低盐/葡萄糖培养基中积累的镍比在完全培养基中培养并补充 10%胎牛血清的细胞多 10 倍。（63）Ni 细胞表面结合似乎是观察到的简单维持培养基中细胞相关镍积累增加的主要原因，因为用胰蛋白酶处理后，这种增加减少了 70%。将镍（2+）结合氨基酸半胱氨酸或组氨酸添加到盐/葡萄糖培养基中会显著降低（63）Ni 的积累，而添加任何不结合镍（2+）的氨基酸均未观察到这种作用。胎牛血清的盐/葡萄糖培养基的补充以浓度依赖的方式降低了（63）Ni（2+）的摄取和 Ni（2+）引起的细胞脱落，而透析（不含氨基酸）血清降低（63）Ni（2+）摄取的效果比未透析血清低 3-5 倍，对镍诱导的细胞毒性也只有轻微的保护作用。用半胱氨酸补充透析血清，使其水平接近整个血清中的水平，部分恢复了其对细胞摄取镍的抑制活性，并完全恢复了其对镍细胞毒性的抑制作用，表明特定氨基酸对血清蛋白在调节镍（2+）摄取和随后的细胞毒性方面起着主要作用。在将细胞暴露于 100 μM HgCl2 或 1 mM NiCl2 2 小时期间，将半胱氨酸添加到盐/葡萄糖培养基中，掩盖了这些金属离子的细胞毒性作用。这些结果表明，细胞外小分子金属离子螯合剂在改变金属摄取水平的金属离子的生物学效应方面具有重要意义。
