微囊藻毒素-LR（MC-LR）对大鼠肝脏脂代谢紊乱的蛋白质组学及计算机模拟研究

Microcystins (MCs) are a family of toxins produced by cyanobacteria. They are one of the most important biotoxins affecting human health through poisoning drinking water and aquatic foods. The liver is the main target organ of MCs, and they can cause liver necrosis or hemorrhage, hepatitis, and hepatocarcinogenesis. Accumulating evidences has indicated that MC-LR caused hepatic lipid metabolism abnormalities, even include the exposure dose levels of MC-LR lower than the reported no observed adverse effect level (NOAEL). However, the exact mechanism of this action remains unclear. It is presumed that the PPARα signaling pathway play a pivotal role in MC-LR acute exposure induced the lipid metabolism disorders on mammals, based on review the literature, our previous work, and pre-experiments. Hence, we would application of multi-disciplinary tools such as chemical proteomics (in vitro), acute exposure experiments (in vivo), and computational simulation approach to reveal the molecular mechanisms of MC-LR acute exposure on mammalian hepatic lipid metabolism abnormalities. The present project is planning to investigate the dynamic changes of the related indicators of PPARα induced by MC-LR, the effects of MC-LR on hepatic proteins expression, and the interactions between MC-LR/MC-LR-GSH and Apo AI. The results of the present project could provide fundamental basis and scientific support for the mechanisms of MCs virulence to human health.

微囊藻毒素（MCs）是一类由蓝藻产生的天然毒素，易通过饮用水和食物链直接威胁人类的健康。MCs主要在肝脏累积，导致肝脏组织出血和（或）坏死，引起人患肝炎并促发肝癌。大量的研究表明MC-LR暴露会诱发肝脏脂类代谢紊乱。特别值得关注的是即使MC-LR暴露的剂量低于世界卫生组织认可的无可见效应水平仍然显著影响小鼠肝脏脂类代谢。但是，人们对MC-LR影响肝脏脂类代谢的分子机制却知之甚少。查阅文献并结合本课题的前期工作，我们发现MC-LR急性染毒诱发脂类代谢紊乱的可能机制与PPARα信号通路密切相关。因此，本项目拟整合化学蛋白质组学（体外实验）、急性染毒（体内实验）、计算机模拟实验三个层次，探究MC-LR急性中毒诱发的PPARα信号通路相关指标的动态变化情况、MC-LR对肝脏蛋白质整体状态的影响、MC-LR与Apo AI之间相互作用的化学本质，从而阐明MC-LR对哺乳动物肝脏脂类代谢胁迫的分子机制。

微囊藻毒素-LR（MC-LR）是由蓝藻产生的天然毒素，由于它对人类健康的威胁而广受关注。大量的研究表明MC-LR暴露会诱发肝脏脂类代谢紊乱。但是，人们对MC-LR影响肝脏脂类代谢的分子机制却知之甚少。在前期工作以及对国内外相关文献的梳理基础上，项目组以体外、体内实验和计算机模拟技术相结合的方式探究PPARα信号通路在微囊藻毒素-LR（MC-LR）诱发的肝脏脂代谢紊乱及急性中毒中的重要作用。化学蛋白质组学发现MC-LR与PPARα 信号通路中的载脂蛋白（Apoa1, Apoa2, Apoa4, Apoa5, Apoc2与Apoe）和脂肪酸结合蛋白（Fabp1）之间的结合，可能是引起肝脏脂代谢紊乱的重要因素。转录组学的结果表明不同剂量MC-LR急性暴露24h后PPAR信号通路都受到显著影响。MC-LR/MC-LR-GSH能够与Apoa1之间形成稳定的复合物，且MC-LR能够改变Apoa1脂质结合能力。GSH修饰之后增大了MC-LR与Apoa1之间的结合是GSH 降低MC-LR毒理作用的可能因素。蛋白质组学的结果同样发现一些与PPARα 信号通路相关的蛋白表达异常，并且KEGG聚类分析发现生物体内钙离子、铁离子以及辅因子（NAD/NAPH）的稳态与MC-LR急性中毒机制密切相关。值得一提的是，组学结果提示脂质代谢紊乱可能会诱发细胞通过铁死亡的方式发生程序性死亡。此外，我们还以组学研究的结果为导向，利用计算机模拟开展了探究小分子化合物与MC-LR潜在靶点蛋白/转运蛋白之间的结合机制以及钙离子在MC-LR诱发细胞凋亡中起到重要作用的相关工作。在本项目的资助下，已在不同SCI期刊上发表论文18篇，培养硕士研究生4名。