基于生物标志物的镰孢毒素联合代谢分子机制及协同暴露评估研究

Due to the wide contamination and , severer toxicity, and largely proven coexistence in food, mycotoxins have caused frequent food poisoning and huge economic losses. Nowadays, research on the combined, low-dose toxicity exposure effect of multiple mycotoxin contamination has been the new frontier of food safety risk assessment. This foundation proposal focuses on the discovery and application of Fusarium toxins exposure biomarkers. By combination of biology, analytical chemistry, metabonomics and food safety, this study aims to disclose the mechanism of combined toxicity biotransformation of Fusarium toxins and apply the exposure assessment based on biomarkers in coordination with total dietary studies for food safety risk assessment. In vitro study is performed for non-targeted screening profiling of individual and multiple mycotoxin exposure biomarkers using a stable isotope tracer strategy. These biomarkers are further confirmed with in vivo study. By invstigating the content and composition change of the biomarkers, the molecular mechanism of combined biotransformation of Fusarium toxins could be deduced. Furthermore, ultra-Ssensitive and multi-targetprecision detection methods for bio fluids should also be established for the confirmed biomarkers and used for determination of biomarkers in human urea from typical areas. By invstigating the content and composition change of the biomarkers, the molecular mechanism of combined toxicity of Fusarium toxins could be deduced. A coordinate exposure assessment of biomarker based assessment and total dietary study can be established for Fusarium toxins.

真菌毒素作为食品中一类重要的天然污染物，不但毒性强烈，且经常污染共存。多种真菌毒素混合暴露问题正引起国内外高度关注。为此，本课题以我国危害严重且广泛共存的两种镰孢毒素为研究对象，以生物标志物的发现与应用为核心，以发掘真菌毒素交互作用分子机制、建立膳食摄入与生物标志物联合评估体系为研究目标，结合生命科学、代谢组学、分析化学、食品安全领域的优势技术与方法，开展一系列理论与应用研究。采用优势互补的人源肝细胞体外代谢模型及活体动物体内代谢模型，借助稳定同位素标记辅助的高分辨质谱非目标筛查技术，联合发现并确证镰孢毒素暴露特征标志物，考察其动态变化规律，揭示多毒素交互作用的分子机制。进而建立典型生物样本中镰孢毒素暴露标志物的精准表征技术，对我国典型地区居民体内暴露生物标志物进行测定，结合毒素膳食摄入量数据，系统分析人类毒素摄入与体内暴露联合评估体系。

本项目以雪腐镰刀菌烯醇（NIV）与脱氧雪腐镰刀菌烯醇（DON）两种镰孢毒素为研究对象，采用肝微粒体体外暴露模型,对毒素的细胞特征代谢产物进行非目标筛查，表明醛酸化为其主要的代谢产物。进而，以大鼠作为典型动物建立暴露模型，对初步筛选出的特征代谢产物进行靶标验证，明确其体内体外代谢的一致性，并最终确认DON、DON-3-GluA、DON-15-GluA、DOM-1为DON的暴露标志物，NIV、NIV-3-GluA为NIV的暴露生物标志物。建立了基于液相色谱-质谱的典型生物样本中镰孢毒素暴露标志物精准表征体系。在此基础上，监测我国河南、安徽等真菌毒素暴露较高的典型地区人群体液样品中DON及ZEN等真菌毒素暴露标志物，对其中真菌暴露标志物的含量、分布进行了研究。对于199份样品，结合总膳食研究数据，系统分析毒素膳食摄入量与体内暴露标志物的相关性，探索建立膳食暴露与体内暴露联合评估体系。结果表明，基于生物标志物的暴露评估方法可以被用于食品安全风险评估中。