The aminoglycoside antibiotic gentamicin is able to alter metabolic activity and morphology of MDCK-C11 cells: a cell model of intercalated cells

It is well known that the aminoglycoside antibiotic gentamicin is capable of causing damage to kidney cells. Given the known involvement of Ca2+ in the nephrotoxic action of gentamicin, the purpose of this study was to establish a relationship between the concentration of intracellular Ca2+ ([Ca2+]i) and cellular cytotoxicity using MDCK-C11 cells, a clone that has several properties that resemble those of intercalated cells of the distal nephron. Changes in [Ca2+]i was determined using fluorescence microscopy. Cell viability was evaluated by the neutral red method, and cell cytotoxicity by the MTT method. The [Ca2+]i gradually increased when cells were exposed to 0.1 mM gentamicin for 10, 20, and 30 min. The presence of extracellular Ca2+ was found to be necessary to stimulate the increase in [Ca2+]i induced by gentamicin, since this stimulus disappeared by using 1.8 mM EGTA (a Ca2+ chelator). Morphological changes were observed with scanning electron microscopy in epithelial cells exposed to the antibiotic. Furthermore, with the MTT method, a decrease in metabolic activity induced by gentamicin was observed, which indicates a cytotoxic effect. In conclusion, gentamicin was able to alter [Ca2+]i, change the morphology of MDCK-C11 cells, and promote cytotoxicity.

众所周知，氨基糖苷类抗生素庆大霉素可造成肾细胞损伤。鉴于已知钙离子（Ca²+）参与庆大霉素的肾毒性作用，本研究旨在利用MDCK-C11细胞——一种在多项特性上与远端肾单位闰细胞相似的细胞克隆——探究细胞内钙离子浓度([Ca²+]i)与细胞毒性之间的关联。本研究采用荧光显微镜法检测[Ca²+]i的变化，通过中性红法评估细胞活力，MTT法则用于检测细胞毒性。当细胞暴露于0.1 mM庆大霉素中10、20及30分钟时，[Ca²+]i水平逐渐升高。研究发现，细胞外钙离子（Ca²+）的存在是庆大霉素诱导[Ca²+]i升高的必要条件，因为使用1.8 mM EGTA（一种钙离子螯合剂）可消除这一诱导效应。扫描电子显微镜观察显示，暴露于该抗生素的上皮细胞出现了形态学改变。此外，通过MTT法检测到庆大霉素可诱导细胞代谢活性降低，这表明其具有细胞毒性作用。综上，庆大霉素可改变[Ca²+]i水平、改变MDCK-C11细胞形态，并诱导细胞毒性产生。