Cultured kidney cells maintained in conventional growth media with high glucose levels exhibit increased glycolytic activity compared to the cells in vivo. In contrast, renal proximal tubules utilize substrates such as ketone bodies and rely on mitochondrial oxidative phosphorylation. LLC-PK1 cells maintain many features of the proximal tubule but are exposed to glucose concentrations ranging from 17-25 mM. This may impact their reliability in predicting mitochondrial toxicity. This study is designed to test the impact of the ketone body acetoacetate on metabolic characteristics of LLC-PK1 cells. Basal respiration, maximal respiration, spare respiratory capacity and ATP-linked respiration were significantly increased in cells grown in growth medium supplemented with 5 mM acetoacetate. In contrast, glycolytic capacity, as well as glycolytic reserve were significantly reduced in the acetoacetate group. There was an increased expression in biomarkers of mitochondrial biogenesis, and an increase in mitochondrial protein expression. Cells grown in medium complemented with acetoacetate displayed a significantly lower LC50 when treated with clotrimazole and diclofenac. There was a marked increase in uncoupled respiration in the presence of diclofenac, while clotrimazole and ciprofibrate significantly decreased respiration in the acetoacetate. The results indicate that acetoacetate complemented media can alter cellular metabolism and increase sensitization to toxicants.

中文翻译：

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乙酰乙酸盐增强氧化代谢和对培养肾细胞毒物的反应

与体内细胞相比，在具有高葡萄糖水平的常规生长培养基中培养的肾细胞表现出增加的糖酵解活性。相比之下，肾近端小管利用酮体等底物并依赖线粒体氧化磷酸化。LLC-PK1 细胞保持近端小管的许多特征，但暴露于 17-25 mM 的葡萄糖浓度。这可能会影响它们预测线粒体毒性的可靠性。本研究旨在测试酮体乙酰乙酸酯对 LLC-PK1 细胞代谢特性的影响。在补充有 5 mM 乙酰乙酸盐的生长培养基中生长的细胞中，基础呼吸、最大呼吸、备用呼吸能力和 ATP 相关呼吸显着增加。相比之下，糖酵解能力，以及乙酰乙酸酯组的糖酵解储备显着降低。线粒体生物发生的生物标志物表达增加，线粒体蛋白表达增加。当用克霉唑和双氯芬酸处理时，在补充有乙酰乙酸盐的培养基中生长的细胞显示出显着较低的 LC50。在双氯芬酸存在下，解偶联呼吸显着增加，而克霉唑和环丙贝特显着降低乙酰乙酸酯中的呼吸。结果表明乙酰乙酸酯补充培养基可以改变细胞代谢并增加对毒物的敏感性。当用克霉唑和双氯芬酸处理时，在补充有乙酰乙酸盐的培养基中生长的细胞显示出显着较低的 LC50。在双氯芬酸存在下，解偶联呼吸显着增加，而克霉唑和环丙贝特显着降低乙酰乙酸酯中的呼吸。结果表明乙酰乙酸酯补充培养基可以改变细胞代谢并增加对毒物的敏感性。当用克霉唑和双氯芬酸处理时，在补充有乙酰乙酸盐的培养基中生长的细胞显示出显着较低的 LC50。在双氯芬酸存在下，解偶联呼吸显着增加，而克霉唑和环丙贝特显着降低乙酰乙酸酯中的呼吸。结果表明乙酰乙酸酯补充培养基可以改变细胞代谢并增加对毒物的敏感性。