Ferruzza S, Scarino M L, Rotilio G, Ciriolo M R, Santaroni P, Muda A O, Sambuy Y
Istituto Nazionale della Nutrizione, 00178 Rome, Università di Roma Tor Vergata, 00133 Rome, Italy.
Am J Physiol. 1999 Dec;277(6):G1138-48. doi: 10.1152/ajpgi.1999.277.6.G1138.
The effects of copper on tight-junction permeability were investigated in human intestinal Caco-2 cells, monitoring transepithelial electrical resistance and transepithelial passage of mannitol. Apical treatment of Caco-2 cells with 10-100 microM CuCl(2) (up to 3 h) produced a time- and concentration-dependent increase in tight-junction permeability, reversible after 24 h in complete medium in the absence of added copper. These effects were not observed in cells treated with copper complexed to L-histidine [Cu(His)(2)]. The copper-induced increase in tight-junction permeability was affected by the pH of the apical medium, as was the apical uptake of (64)CuCl(2), both exhibiting a maximum at pH 6.0. Treatment with CuCl(2) produced a concentration-dependent reduction in the staining of F actin but not of the junctional proteins zonula occludens-1, occludin, and E-cadherin and produced ultrastructural alterations to microvilli and tight junctions that were not observed after treatment with up to 200 microM Cu(His)(2) for 3 h. Overall, these data point to an intracellular effect of copper on tight junctions, mediated by perturbations of the F actin cytoskeleton.
在人肠道Caco-2细胞中研究了铜对紧密连接通透性的影响，监测跨上皮电阻和甘露醇的跨上皮转运。用10 - 100微摩尔/升氯化铜（长达3小时）对Caco-2细胞进行顶端处理，导致紧密连接通透性呈时间和浓度依赖性增加，在无添加铜的完全培养基中培养24小时后可逆转。在用与L-组氨酸络合的铜[Cu(His)₂]处理的细胞中未观察到这些效应。铜诱导的紧密连接通透性增加受顶端培养基pH值的影响，(⁶⁴)CuCl₂的顶端摄取也是如此，两者在pH 6.0时均表现出最大值。用氯化铜处理导致F肌动蛋白染色呈浓度依赖性降低，但紧密连接蛋白闭合蛋白-1、闭合蛋白和E-钙黏蛋白的染色未受影响，并且产生了微绒毛和紧密连接的超微结构改变，而在用高达200微摩尔/升Cu(His)₂处理3小时后未观察到这些改变。总体而言，这些数据表明铜对紧密连接的细胞内效应是由F肌动蛋白细胞骨架的扰动介导的。
