Sequencing the exposome: developing an integrated approach using nontargeted mass spectrometry and computational chemistry

暴露组测序：使用非靶向质谱和计算化学开发综合方法

• 批准号: RGPIN-2020-06628
• 负责人: Jobst, Karl
• 金额: $ 2.99万
• 依托单位: Memorial University of Newfoundland
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=717831
• 关键词: Sequencing; exposome; developing; integrated; approach

The exposome encompasses the totality of environmental exposures during a lifetime. In chemistry and chemical biology, these exposures manifest as endogenous and exogenous chemicals that result from diet, lifestyle, radiation, stress, and exposure to environmental pollutants. Unlike the genome, the exposome is variable and thus requires frequent, cost-effective and reliable measurements of exposures that evolve over time, most appropriately by sampling small quantities of blood (e.g. dried-blood spots). Such measurements will be vital in order to identify the causes of most chronic diseases, but the obstacles to further progress are formidable: c. 90% of unknown pollutants in a drop of blood are not detectable using existing analytical platforms; and the identities of most environmental toxicants and their role in causing chronic disease are unknown! My group's research will address these challenges through the development of innovative mass spectrometry (MS) techniques, viz. flow modulated multidimensional gas chromatography-atmospheric pressure ionization (GCxGC-API), complemented by state-of-the-art computational tools. The proposed analytical platform affords unparalleled separation and significantly improves detection limits when coupled with an API source that is resilient to high flows. Despite its promise, this has not been previously attempted! The development of this approach will enable: the identification of unknown pollutants with 3-50 microliters of blood (1 PhD, 1 BSc), a remarkable improvement over existing methodologies that require pooled sampling and excessive blood volumes >300uL; and innovative hyphenation of ionization (1 MSc) and activation (1 PhD, 1 BSc) techniques that will provide new information critically needed to identify unknown toxicants. Nontargeted screening (NTS) is the term-of-art for qualitative experiments aimed at identifying unknown organic compounds using MS. The prevailing thought is that a compound's structure must be elucidated prior to assessing environmental significance, but this approach is impractical considering sample complexity. We suggest that that the environmental significance of an unknown chemical may be inferred from its behavior (and reactivity) in the mass spectrometer without a priori knowledge of its structure. Trainees in my lab will: develop automated software that accelerates pollutant discovery (1 PhD, 1 BSc); investigate and exploit the rich chemistry occurring in the mass spectrometer that mirrors in vivo metabolism and can be used to differentiate toxic from non-toxic chemicals (1 PhD, 1 BSc); and finally, conduct reconnaissance studies (3 MSc, 1 BSc) aimed at answering the question: What risk do these newfound pollutants pose to the environment and health? It is anticipated that the results from this research program will help guide the creation of effective environmental regulation; and guide industry on the development of safer, more sustainable chemicals.

危险组包括一生中环境暴露的全部。在化学和化学生物学中，这些暴露表现为饮食、生活方式、辐射、压力和暴露于环境污染物引起的内源性和外源性化学物质。与基因组不同，基因组是可变的，因此需要频繁、具有成本效益和可靠地测量随时间推移而演变的暴露，最适当的方法是取样少量血液（例如干血斑）。这种测量对于确定大多数慢性病的原因至关重要，但进一步取得进展的障碍是巨大的：使用现有的分析平台，一滴血液中90%的未知污染物是检测不到的;大多数环境毒物的身份及其在导致慢性疾病中的作用是未知的！ 我们小组的研究将通过开发创新的质谱（MS）技术来应对这些挑战，即流量调制多维气相色谱-大气压电离（GCxGC-API），并辅以最先进的计算工具。所提出的分析平台提供了无与伦比的分离，并显着提高检测限时，与API源，是弹性高流量。尽管它的承诺，这是以前没有尝试过！这种方法的发展将使：用3-50微升血液鉴定未知污染物（1位博士，1位理学士），这是对现有方法的显著改进，现有方法需要合并采样和超过300 uL的过量血量;和创新的离子化（1硕士）和活化的联用（1博士，1理学士）技术，将提供新的信息，迫切需要确定未知的有毒物质。 非靶向筛选（NTS）是定性实验的术语，旨在使用MS识别未知的有机化合物。普遍的想法是，在评估环境意义之前必须阐明化合物的结构，但考虑到样品的复杂性，这种方法是不切实际的。我们建议，一个未知的化学品的环境意义可以推断出它的行为（和反应性）在质谱仪没有先验知识的结构。在我的实验室实习生将：开发自动化软件，加速污染物发现（1博士，1理学士）;研究和利用质谱仪中发生的丰富化学反应，反映体内代谢，可用于区分有毒和无毒化学物质（1个博士，1个理学士）;最后，进行勘察研究（3理学硕士，1理学士）旨在回答这个问题：这些新发现的污染物对环境和健康构成什么风险？预计这项研究计划的结果将有助于指导制定有效的环境法规，并指导工业界开发更安全、更可持续的化学品。