展青霉素经线粒体途径引起人肾毒性的分子机制

Patulin（Patulin,PAT）, a secondary metabolites mainly produced by Penicillium and Aspergillus, has became one of the major biological contamination in fruit and cereal products worldwide. Because of the acute and chronic toxicity, accumulation toxicity, patulin has become a major issue related to food safety. At present,more researches focused on the testing methods and removal technologies of patulin, but the cytotoxic mechanism of patulin has been reported rarely. Early we have confirmed that patulin caused the cell viability of human embryonic kidney cells reducing , apoptosis, mitochondrial respiratory enzyme expression disorders and impaired mitochondrial function. The present study plan to better understand the neprotoxicity mechanism of patulin via mitochondrial pathway both in vitro and in vivo, and to explore the toxic effect from the function of mitochondrial especially respiratory complex I, II, III, IV and V, as well as caspase cascade signal pathway. Meanwhile, in order to screen the detail toxic molecular targets of patulin, the iTRAQ proteome technology should be adopted. The studies should provide potent scientific basis for the explaination of molecular mechanism of the human cells under PAT stress and the corresponding food safety issues, in the meantime, it should provide reliable scientific guarantee for the biological treatment field and human health.

展青霉素(PAT)是曲霉属和青霉属等产生的一类次级代谢产物，是世界范围内水果及谷物等制品的主要污染源。因其急、慢性毒作用及蓄积性，已成为涉及食品安全的重大问题而备受关注。目前对PAT的研究多集中检测方法及脱除技术方面，而对于其细胞毒性损伤机制鲜有报道。前期我们证实，PAT引起人胚肾细胞存活率降低、细胞发生凋亡、线粒体呼吸酶表达紊乱、线粒体功能受损。本课题拟从体外、体内水平研究棒曲霉素PAT经线粒体途径引起的肾毒性机制，重点关注对线粒体呼吸酶、caspase级联信号系统的影响。同时，采用iTRAQ技术筛选PAT经线粒体致毒的蛋白靶标，探索相应的作用机制信号网络。本项目的研究结果可为解释人体细胞对PAT应激反应的分子机制及相应食品安全问题提供有力的科学基础。

展青霉素是曲霉属和青霉属等产生的一类次级代谢产物，是水果、谷物及药材等制品的主要污染源。因其急、慢性毒作用及蓄积性，已成为涉及食品安全的重大问题而备受关注。本项目以人胚肾细胞293T细胞为实验模型，结合动物试验，从毒性效应、细胞及组织的形态、生理生化，氧化胁迫、线粒体损伤、凋亡基因和蛋白表达等方面探讨展青霉素可能的毒性机制。主要研究结论有：.1.PAT对293T细胞具有生长抑制作用和致凋亡的毒性效应，且具有显著的剂量-效应关系和时间-效应关系。.2.PAT造成了肾细胞凋亡，肾小球发生明显的纤维硬化情况，且出现胞间充血和炎症，对肾脏功能造成了损伤。.3.PAT引起了细胞氧化还原水平的改变，使细胞处于氧化应激状态。.4.PAT引起了KM小鼠氮代谢障碍，说明其对小鼠的肾脏功能造成了损伤。.5.PAT诱导了线粒体膜通透性增加，细胞及肾脏内三磷酸腺苷(Adenosine 5'-triphosphate，ATP)水平下降，活性氧(Reactive oxygen species，ROS)含量累积，这说明线粒体在 PAT 诱导的细胞损伤及细胞凋亡过程中起了重要作用。.6.线粒体受到损伤后，释放细胞色素到胞浆中，Cyt-C过表达，激活了半胱氨酸蛋白酶(Cysteine-requiring Aspartate Protease, Caspase)酶发生级联反应，Caspase级联反应被启动，从而造成细胞凋亡效应因子被加速激活。导致细胞凋亡。 .7.研究证实，Caspase家族成员在细胞凋亡的整个过程中起到关键作用，通过启动外源性细胞凋亡传导通路及间接启动内源性细胞凋亡传导通路参与细胞凋亡。许多凋亡相关因子参与了对Caspase家族的调控。.本项目的研究结果可为解释人体细胞对PAT应激反应的分子机制及相应食品安全问题提供有力的科学基础。