基于蛋白质组学研究AFB1致雏鸡肝脏毒性的机制及其营养调控

Dietary exposure to aflatoxin B1 (AFB1) is harmful to poultry health and performance. AFB1 is primarily delivered into the liver and bioactivated to the highly reactive exo-AFB1-8,9-epoxide (AFBO), which forms adducts within the DNA and causes hepatic injury. However, the hepatotoxic mechanisms of AFB1 are poorly understood. It is therefore critical to systematically study the hepatotoxic mechanisms of AFB1 in chicks as well as developing nutritional strategies to prevent its adverse effects. This project intends to use iTRAQ technology to screen potential candidate proteins that could be involved in the hepatotoxic mechanisms of AFB1 in chicks. Identified potential candidate proteins would then be further confirmed through western blot analysis. Furthermore, gene overexpression and RNAi technologies will be used to explore the functional properties of the candidate proteins involved in aflatoxicosis using chick primary hepatocytes. On this basis, we will then explore whether the nutrient (selenium) could alleviate aflatoxicosis in chicks through the regulation of these crucial proteins. These studies will systematically reveal the molecular mechanisms of the hepatotoxicity of AFB1 in chicks and its nutritional detoxification (selenium), which can provide the scientific basis needed for development nutritional strategies (selenium) to prevent its adverse effects in chicks.

黄曲霉毒素B1（AFB1）对雏禽生产危害极大，其主要在肝脏代谢生成毒性极强的AFB1-外-8,9-环氧化物（AFBO），AFBO可与DNA结合产生基因毒性作用而导致雏禽肝脏损伤，但是AFBO基因毒性作用诱导哪些关键蛋白异常表达而导致肝脏损伤，目前尚不是很清楚。因此，系统解析AFB1致雏鸡肝脏损伤的分子机制及开展相关营养措施防治其毒害作用尤为迫切。本项目拟通过iTRAQ定量蛋白质组学技术筛选AFB1致雏鸡中毒模型中肝脏中差异表达的候选关键蛋白，通过蛋白质印迹法等验证差异表达蛋白。然后，应用RNA干扰及基因超表达技术鉴定候选关键蛋白在AFB1致雏鸡原代肝细胞损伤过程中的作用。在此基础上，探究营养素（硒）是否可通过调控相关关键蛋白或其信号通路而缓解AFB1致雏鸡的毒性。本研究旨在系统阐明AFB1致雏鸡肝脏损伤及营养素（硒）缓解其毒性的分子机制，可为营养素（硒）防治雏鸡AFB1中毒提供理论依据。

黄曲霉毒素B1（AFB1）对雏禽生产危害极大，其主要富集于雏禽肝脏进行代谢，生成毒性极强的AFB1-外-8,9-环氧化物（AFBO），AFBO可与DNA结合产生基因毒性作用而导致雏禽肝脏损伤。本项目运用iTRAQ定量蛋白质组学等技术筛选到了522个蛋白质在AFB1致雏鸡肝脏损伤中差异表达，这些蛋白主要参与细胞代谢、氧化还原反应以及脂肪酸代谢等过程，涉及MAPK信号通路，细胞凋亡、细胞色素P450的药物代谢及谷胱甘肽代谢等信号通路。此外，RNA干扰及基因超表达技术验证研究发现金属硫蛋白（MT）在AFB1致肝脏毒性中起重要作用。另外，蛋白组学结果显示64个蛋白质在硒缓解AFB1致雏鸡肝脏损伤中起主要作用，这些蛋白质主要参与酮酸代谢、有机酸代谢及调控氧化还原酶活性等过程有关，涉及PPAR、细胞色素P450的药物代谢及谷胱甘肽代谢等信号通路。研究结果可为营养素（硒）防治雏鸡AFB1中毒提供理论依据。