学 术 讲 座
题 目 : 纳米材料助推质谱技术发展
讲座人 : 蔡宗苇 教授
时 间 : 2018年9月20日上午10:00
地 点 : 卢嘉锡楼202报告厅
蔡宗苇教授，质谱分析专家，长期从事质谱的基础理论和应用研究，特别擅长于高分辨质谱、GC-MS、LC-MS及其在环境、生物、药物和痕量有机污染物分析方面的应用研究，目前主要从事人体健康、疾病的代谢组学、蛋白质组学和质谱成像研究，已在国际专业刊物上发表400多篇论文,现受聘为国际质谱杂志“Rapid Communication in Mass Spectrometry”的Editor。蔡教授多次被联合国环境规划署全球持久性有机污染物监测委员会邀请参加讨论和制定关于全球和亚太区域持久性有机污染物监测计划的执行和报告，并于2008年和2014年分别受联合国环境规划署聘请作为Principal Author编写第一个和第二个斯德哥尔摩公约下亚太地区持久性有机污染物监测和控制报告。蔡教授是国家自然科学基金杰出青年基金获得者(B类，2003) ，以及教育部“长江学者”讲座教授 (2013)。
Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) provides a powerful tool in the analysis of diverse molecules because of its high sensitivity, high-throughput analysis and simplicity of operation. To improve the signal of small molecules (<500 Da) due to the interference of the matrix ions, various matrices, such as porous silicon, nanomaterials, polymers and carbon materials have been developed. Graphene, for example, is a two-dimensional carbon nanomaterial with many outstanding properties including environmentally friendly and good conductivity and large specific surface. It has also exhibited tremendous application potential in detecting small molecules including biological compounds and environmental organic pollutants by using MALDI-TOF MS because of its better matrix functions.
Traditional environmental toxicology applied biological and chemical techniques to explore toxicological effects and mechanisms of environmental pollutants in cells, animals and human samples. Study of spatial characteristics of biomolecule remains under-explored, such as heterogeneity of biological samples and spatial distribution of biomarkers. Mass spectrometry imaging (MSI) provides a comprehensive and high-throughput in situ analysis on tissues sections, it also showed the feature of macromolecules (proteins and peptides) and small molecules (lipids and metabolites), such as composition, abundance and specific distribution. In our study, a comprehensive method involving MS-based global lipidomics and matrix-assisted laser desorption/ionization-mass spectrometry (MALDI)-MSI have been applied to study the toxic effects of bisphenol A (BPA) substitutes and the underlying mechanisms on mouse model. A typical example of bisphenol S (BPS) will be used to illustrate the nephrotoxicity of BPA substitutes on mouse model. Our results demonstrated that BPS exposure remarkable perturbed abundances of 91 potential markers that mainly involved in five metabolic pathways. We elucidated the lipids spatial heterogeneity by using morphological analysis, probabilistic latent semantic analysis and co-registered multimodal three-dimensional (3D)-MSI. In morphological analysis, both 10 and 100 μg BPS/kg body weight/day induced significant nephrotoxicity to mice, including glomerular necrosis in renal cortex, cloudy swelling in renal medulla, interstitial collapsing in renal pelvis. Observed significant variations of morphology, lipid accumulation and metabolism in renal cortex implicated that lipids in renal cortex were more sensitive to BPS exposure than renal medulla and pelvis. It might be used in novel specificity evaluation and early diagnosis for environmental pollutants-induced kidney diseases.