Zhang Boyang, Shen Xiao Li, Liang Rui, Li Yuzhe, Huang Kunlun, Zhao Changhui, Luo Yunbo, Xu Wentao
Laboratory of food safety and Molecular Biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, PR China.
Laboratory of food safety and Molecular Biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, PR China; School of Public Health, Zunyi Medical University, Zunyi, Guizhou 563003, PR China.
J Proteomics. 2014 Apr 14;101:154-68. doi: 10.1016/j.jprot.2014.02.017. Epub 2014 Feb 22.
Ochratoxin A (OTA) is a common kind of mycotoxin and food contaminant, which has various toxicological effects, especially nephrotoxicity. Our previous work about OTA-induced renal cytotoxicity indicated that mitochondrial Lon Protease 1 (Lonp1) might play a protective role. Lonp1 is a multifunctional ATP-dependent protease which mainly participates in mitochondrial proteolysis and protein quality control. The study aimed at probing how Lonp1 functioned in OTA-induced renal cytotoxicity. By means of RNA interference, we down-regulated the expression of Lonp1 in HEK293 cells. Cell viability results revealed that cells with Lonp1 deficiency were more vulnerable to OTA. Then we identified differentially expressed proteins between Lonp1 knock-down cells and scrambled control both in the absence and presence of OTA, using iTRAQ-based quantitative proteomics approach. Thirty-four proteins were differentially expressed as a result of Lonp1 deficiency, while forty-four proteins were differentially expressed in response to both Lonp1 deficiency and OTA treatment. By function summary and pathway analysis, we presumed that Lonp1 realized its protective function in the resistance to OTA-induced renal cytotoxicity via 4 processes: defensing against OTA-induced oxidative stress in the mitochondria; regulating protein synthesis, modification and repair; maintaining the balance of carbohydrate metabolism; and assisting in mtDNA maintenance.
OTA is a kind of mycotoxin that seriously threatens human health and has various toxicological effects. However, the mechanisms of its toxicity have not been exactly elucidated yet. The method of combination of RNAi and iTRAQ-based quantitative proteomics paves the way to gain a better understanding of the toxicity mechanisms of OTA. The present study, for the first time, verified the protective role of Lonp1 in OTA-induced renal cytotoxicity and clarified the defensive mechanism. Proteomic changes in Lonp1 deficient cells induced by OTA added new knowledge to OTA cytotoxicity.
赭曲霉毒素A（OTA）是一种常见的霉菌毒素和食品污染物，具有多种毒理学效应，尤其是肾毒性。我们之前关于OTA诱导肾细胞毒性的研究表明，线粒体Lon蛋白酶1（Lonp1）可能发挥保护作用。Lonp1是一种多功能的ATP依赖性蛋白酶，主要参与线粒体蛋白水解和蛋白质质量控制。本研究旨在探究Lonp1在OTA诱导的肾细胞毒性中如何发挥作用。通过RNA干扰，我们下调了HEK293细胞中Lonp1的表达。细胞活力结果显示，Lonp1缺陷的细胞对OTA更敏感。然后，我们使用基于iTRAQ的定量蛋白质组学方法，鉴定了在有无OTA的情况下，Lonp1敲低细胞与对照细胞之间差异表达的蛋白质。由于Lonp1缺陷，有34种蛋白质差异表达，而在Lonp1缺陷和OTA处理的双重作用下，有44种蛋白质差异表达。通过功能总结和通路分析，我们推测Lonp1通过4个过程在抵抗OTA诱导的肾细胞毒性中实现其保护功能：抵御OTA诱导的线粒体氧化应激；调节蛋白质合成、修饰和修复；维持碳水化合物代谢平衡；以及协助维持线粒体DNA。
OTA是一种严重威胁人类健康且具有多种毒理学效应的霉菌毒素。然而，其毒性机制尚未完全阐明。RNA干扰和基于iTRAQ的定量蛋白质组学相结合的方法为更好地理解OTA的毒性机制铺平了道路。本研究首次验证了Lonp1在OTA诱导的肾细胞毒性中的保护作用并阐明了防御机制。OTA诱导的Lonp1缺陷细胞中的蛋白质组变化为OTA细胞毒性增添了新知识。
