Lei Rong, Zhao Fei, Tang Cheng-Yuan, Luo Min, Yang Shi-Kun, Cheng Wei, Li Xu-Wei, Duan Shao-Bin
Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, China.
Department of Nephrology, The Third Xiangya Hospital, Central South University, Changsha, China.
Cell Physiol Biochem. 2018;46(3):975-985. doi: 10.1159/000488827. Epub 2018 Apr 19.
BACKGROUND/AIMS: Contrast induced-acute kidney injury (CI-AKI) is one of the most common causes of acute kidney injury (AKI) in hospitalized patients. Mitophagy, the selective elimination of mitochondria via autophagy, is an important mechanism of mitochondrial quality control in physiological and pathological conditions. In this study, we aimed to determine effects of iohexol and iodixanol on mitochondrial reactive oxygen species (ROS), mitophagy and the potential role of mitophagy in CI-AKI cell models.
Cell viability was measured by cell counting kit-8. Cell apoptosis, mitochondrial ROS and mitochondrial membrane potential were detected by western blot, MitoSOX fluorescence and TMRE staining respectively. Mitophagy was detected by the colocalization of LC3-FITC with MitoTracker Red, western blot and electronic microscope.
The results showed that mitophagy was induced in human renal tubular cells (HK-2 cells) under different concentrations of iodinated contrast media. Mitochondrial ROS displayed increased expression after the treatment. Rapamycin (Rap) enhanced mitophagy and alleviated contrast media induced HK-2 cells injury. In contrast, autophagy inhibitor 3-methyladenine (3-MA) down-regulated mitophagy and aggravated cells injury.
Together, our finding indicates that iohexol and iodixanol contribute to the generation of mitochondrial ROS and mitophagy. The enhancement of mitophagy can effectively protect the kidney from iodinated contrast (iohexol)-induced renal tubular epithelial cells injury.
背景/目的：对比剂诱导的急性肾损伤（CI-AKI）是住院患者急性肾损伤（AKI）最常见的病因之一。线粒体自噬是通过自噬选择性清除线粒体，是生理和病理条件下线粒体质量控制的重要机制。在本研究中，我们旨在确定碘海醇和碘克沙醇对线粒体活性氧（ROS）、线粒体自噬的影响以及线粒体自噬在CI-AKI细胞模型中的潜在作用。
采用细胞计数试剂盒-8检测细胞活力。分别通过蛋白质免疫印迹法、MitoSOX荧光法和TMRE染色检测细胞凋亡、线粒体ROS和线粒体膜电位。通过LC3-FITC与MitoTracker Red的共定位、蛋白质免疫印迹法和电子显微镜检测线粒体自噬。
结果显示，在不同浓度的碘化造影剂作用下，人肾小管细胞（HK-2细胞）中诱导了线粒体自噬。处理后线粒体ROS表达增加。雷帕霉素（Rap）增强线粒体自噬并减轻造影剂诱导的HK-2细胞损伤。相反，自噬抑制剂3-甲基腺嘌呤（3-MA）下调线粒体自噬并加重细胞损伤。
总之，我们的研究结果表明碘海醇和碘克沙醇促进线粒体ROS的产生和线粒体自噬。增强线粒体自噬可有效保护肾脏免受碘化造影剂（碘海醇）诱导的肾小管上皮细胞损伤。
