Aleo M F, Morandini F, Bettoni F, Tanganelli S, Vezzola A, Giuliani R, Steimberg N, Apostoli P, Mazzoleni G
Department of Biochemical Sciences, Unit of Biochemistry, School of Medicine, University of Brescia, Via Valsabbina, 19, 25123 Brescia, Italy.
Toxicol In Vitro. 2002 Aug;16(4):457-65. doi: 10.1016/s0887-2333(02)00030-9.
In this study, the early nephrotoxic potential of mercuric chloride (HgCl(2)) has been evaluated in vitro, by exposing a renal-derived cell system, the tubular epithelial Madin-Darby canine kidney (MDCK) cell line, to the presence of increasing HgCl(2) concentrations (0.1-100 microM) for different periods of time (from 4 to 72 h). As possible biological markers of the tubular-specific toxicity of HgCl(2) in exposed-MDCK cultures we analysed: (i) critical biochemical parameters related to oxidative stress conditions and (ii) gap-junctional function (GJIC). HgCl(2) cytotoxicity was evaluated by cell-density assay. The biochemical analysis of the pro-oxidant properties of the mercuric ion (Hg(2+)) was performed by evaluating the effect of the metal salt on the antioxidant status of the MDCK cells. The cell glutathione (GSH) content and the activity of glutathione peroxidase (Gpx) and catalase (Cat), two enzymes engaged in the H(2)O(2) degradation, were quantified. HgCl(2) influence on MDCK GJIC was analysed by the microinjection/dye-transfer assay. HgCl(2)-induced morphological changes in MDCK cells were also taken into account. Our results, proving that subcytotoxic (0.1-10 microM) HgCl(2) concentrations affect either the antioxidant defences of MDCK cells or their GJIC, indicate these critical functions as suitable biological targets of early mercury-induced tubular cell injury.
在本研究中，通过将一种肾源性细胞系统——肾小管上皮的犬肾Madin-Darby（MDCK）细胞系暴露于浓度不断增加（0.1 - 100微摩尔）的氯化汞（HgCl₂）中不同时间段（4至72小时），对氯化汞（HgCl₂）的早期肾毒性潜力进行了体外评估。作为暴露于HgCl₂的MDCK培养物中HgCl₂肾小管特异性毒性的可能生物学标志物，我们分析了：（i）与氧化应激条件相关的关键生化参数，以及（ii）缝隙连接功能（GJIC）。通过细胞密度测定评估HgCl₂的细胞毒性作用。通过评估金属盐对MDCK细胞抗氧化状态的影响，对汞离子（Hg²⁺）的促氧化特性进行生化分析。对细胞谷胱甘肽（GSH）含量以及参与过氧化氢（H₂O₂）降解的两种酶——谷胱甘肽过氧化物酶（Gpx）和过氧化氢酶（Cat）的活性进行了定量分析。通过显微注射/染料转移测定分析HgCl₂对MDCK细胞GJIC的影响。还考虑了HgCl₂诱导的MDCK细胞形态变化。我们的结果表明，亚细胞毒性浓度（0.1 - 10微摩尔）的HgCl₂会影响MDCK细胞的抗氧化防御或其GJIC，表明这些关键功能是汞诱导的早期肾小管细胞损伤的合适生物学靶点。
