乳铁蛋白保护AFM1对肠道上皮细胞紧密连接蛋白损伤的机制

Aflatoxin M1 (AFM1) is a major mycotoxin in milk. Many studies have invested that mycotoxin can cause infections of intestinal epithelial tight junctions (TJs). The functional activity of lactoferrin (Lf) in milk could reduce the damage effects of mycotoxin on cellular oxidation and DNA damage. Hence, the hypothesis of this study is to verify the protection effects of Lf on AFM1-induced damage. Investigating the balance of “Nutrition-Safe” in food could improve our knowledge on food safety. In this study, as the first barrier of intestinal epithelial against mycotoxin, the Caco-2 cells were selected to achieve the three levels of gene expression profile, protein expression profile and barrier function abnormality. To study the internal molecular mechanism, bioinformatics, computer prediction target, molecular biology, and other technique are used to construct cross-omics regulatory network of the protection of Lf on the TJs injury. In addition, the rat assay will be used to verify the key protein and pathways inside the Lf protective mechanism. The results will provide an important scientific basis for exploring the protective mechanism of Lf on AFM1-induced intestinal injury, which is of great significance for the investigation of new functions of milk and milk products and the protection of human health.

黄曲霉毒素M1（AFM1）是奶中主要的一类致癌物质。有研究证实，霉菌毒素会诱发肠道上皮细胞紧密连接蛋白（TJs）损伤。然而，牛奶中乳铁蛋白（Lf）可能具有可以降低AFM1对细胞氧化和DNA损伤功能。为此，本项目提出假设：牛奶中的Lf对牛奶中AFM1对机体造成的损伤具有保护作用，探索食物本身内在的“营养-安全”平衡，将拓展人们对食品安全的认识。本研究选择机体防御AFM1第一道屏障的分化肠道上皮Caco-2细胞为模型，从基因表达谱、蛋白表达谱、屏障功能异常三个层面，利用生物信息学、计算机预测靶标和分子生物学等技术手段，构建Lf保护肠道上皮细胞TJs损伤的跨组学调控网络，解析其分子机制，并利用小鼠攻毒和保护实验，验证参与Lf保护机制的关键蛋白和相关通路。研究结果将为科学探索Lf对AFM1致肠道细胞损伤保护作用机制提供重要科学依据，对挖掘奶及奶产品新功能，保护人体健康具有重要意义。

黄曲霉毒素M1（AFM1）是奶中主要的一类致癌物质。研究证实，霉菌毒素会诱发肠道上皮细胞紧密连接蛋白（TJs）损伤。本研究选择机体防御AFM1第一道屏障的分化肠道上皮Caco-2细胞为模型，从基因表达谱、蛋白表达谱、屏障功能异常三个层面，利用生物信息学、计算机预测靶标和分子生物学等技术手段，构建Lf保护肠道上皮细胞TJs损伤的跨组学调控网络，解析其分子机制。.在本研究中，使用Balb/C小鼠和分化的Caco-2细胞表明LF干预降低了afm1诱导的肠道通透性增加，改善了肠道通透性claudin-3、occludin和ZO-1蛋白的表达，修复了受损的肠屏障。用转录组和蛋白质组来阐明潜在的机制。发现LF可减轻AFM1引起的肠屏障功能障碍，与肠细胞相关生存相关通路，如细胞周期、凋亡、MAPK信号通路和肠道完整性相关通路包括内吞、紧密连接、贴壁连接和缝隙连接。交叉组学分析表明，胰岛素受体(INSR)、细胞质FMR1相互作用蛋白2 (CYFIP2)，胞质分裂的奉献子1(DOCK1)和核糖核苷酸还原酶调节亚基M2(RRM2)是LF修复受损肠屏障的潜在关键调控因子。 .研究结果证实，乳铁蛋白可有效缓解AFM1引起的小鼠肠道屏障损伤，抑制AFM1诱导的小鼠肠道组织形态学改变，缓解紧密连接损伤，缓解AFM1有道的分化Caco-2细胞损伤。