铜对人类肠道上皮Caco-2细胞的毒性研究

目的　了解铜对人类肠道上皮Caco 2细胞的毒性影响。方法　应用噻唑蓝 (MTT)实验、P 糖蛋白(P gp)活性检测实验、活性氧检测及克隆形成实验研究铜对肠道上皮Caco 2细胞的毒性及可能作用机制 ,同时利用Caco 2细胞和肠炎沙门氏菌为模型 ,研究铜对Caco 2细胞对细菌侵入和存活易感性的影响。结果　在一定的暴露场景下 ,铜可明显地降低细胞的活力 ,抑制细胞膜表面P gp的活性 ,促进细胞内活性氧自由基的产生 ,降低细胞的克隆形成能力。此外 ,细胞经铜暴露后 ,肠炎沙门氏菌侵入细胞的数量增加 ,但细胞内存活的细菌数量却下降。结论　过量的铜可导致Caco 2细胞氧化损伤 ,从而引起更广泛的细胞毒性效应 ,但其对细胞对细菌侵入和存活易感性的影响有待进一步研究。

Toxicological effects of copper on human intestinal Caco-2 cells

Objective To study the toxicological effects of copper on human intestinal Caco-2 cells.Methods The effects of copper on human intestinal Caco-2 cells were evaluated by MTT conversion, intra-cellular production of reactive oxygen species (ROS), cloning efficiency and changes of P-glycoprotein (P-gp) activities in Caco-2 cells. In addition, Caco-2 cells and Salmonella enteritidis served as the models to examine the effect of copper on the host-parasite interaction. Results Copper induced a dose-dependent decrease of cell viability measured by MTT assay; by using the fluorescent probe 2,7-dichlorofluorescin diacetate, a significant increase of ROS production in Cu-treated cells was detected; the significant time- and dose-dependent decrease of P-gp activities in Cu-treated cells was demonstrated by increased accumulation of rhodamine 123 in cells. Copper treatment also increased the efficiency of the bacterial invasion, but decreased the number of bacteria surviving in the intracellular environment. Conclusion Copper induced a variety of toxicological endpoints which might be caused by oxidative damage, but the effect of copper on cell-bacteria interaction needs to be further investigated.