CAREER: Elucidating the Roles of Extracellular Metal Ions in Gut Microbiota Interactions

在化学系生命过程化学项目的支持下，休斯顿大学的Melissa Zastrow正在研究金属离子如何影响肠道微生物群中的细胞-细胞和细胞-宿主相互作用。金属离子如钙、铁和锌在生物学中起着关键的调节、催化和结构作用。在肠道微生物群中，这些必需元素的可用性的变化与感染和疾病沿着的不同细菌物种的定殖变化有关，但潜在的分子机制尚不清楚。拟议的研究调查了金属如何影响细菌和宿主蛋白质之间的相互作用。揭示金属如何影响肠道微生物群的分子机制可以导致新的治疗方法，并为更有效地使用当前的医学治疗提供指导。这些研究将与一个互动的生物无机培训项目的发展，“无机化学在生物界面”（ICBI）研讨会，这是集中在调查金属离子在生物界面的作用，并为本科生和研究生量身定制。参与的学生将有机会从事跨学科研究，同时促进他们作为科学家的成长。该研究项目的中心是阐明金属影响肠道微生物群中细胞-细胞和细胞-宿主相互作用的基本机制。数百种微生物物种共存于胃肠道中，并可通过细胞-细胞或细胞-宿主相互作用相互作用。金属的变化可以通过与细菌细胞表面结合来增强或破坏这些相互作用，包括表面蛋白或宿主蛋白如粘蛋白。拟议的工作将使用来自乳杆菌科的细菌以及生物化学和分析方法的组合来建立金属影响1）细菌细胞-细胞相互作用和2）细菌与宿主粘蛋白之间的细胞-宿主相互作用的机制。为了测试金属对细胞间相互作用的影响，将使用生物化学和显微镜表征来测量单种和多种系统中的生物膜形成。类似的技术将用于探测单种和多种系统中的细胞-粘蛋白相互作用。定点突变将用于研究表面蛋白金属结合位点在介导细胞-细胞和细胞-宿主相互作用中的作用。总的来说，这些研究将验证金属可以通过与特定的细胞表面大分子和宿主蛋白质结合来介导肠道微生物群中细菌相互作用的假设。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With the support of the Chemistry of Life Processes program in the Division of Chemistry, Melissa Zastrow of the University of Houston is studying how metal ions affect cell-cell and cell-host interactions in the gut microbiota. Metal ions such as calcium, iron, and zinc play critical regulatory, catalytic, and structural roles in biology. In gut microbiota, changes to the availability of these essential elements are linked to changes in the colonization of different bacterial species along with infection and disease, but the underlying molecular mechanisms are unclear. The proposed research investigates how metals affect interactions between bacteria and host proteins. Uncovering molecular mechanisms for how metals affect the gut microbiota can lead to novel therapeutics and provide guidance for more effective use of current medical treatments. These studies will be integrated with the development of an interactive bioinorganic training project, the “Inorganic Chemistry at Biological Interfaces” (ICBI) workshop, which is centered on investigating the roles of metal ions at biological interfaces and tailored to undergraduate and graduate students. Participating students will have the opportunity to engage in interdisciplinary research while furthering their growth as scientists.This research project centers on elucidating the fundamental mechanisms through which metals affect cell-cell and cell-host interactions in the gut microbiota. Hundreds of microbial species co-exist in the gastrointestinal tract and can interact via cell-cell or cell-host interactions. Changes in metals could enhance or disrupt these interactions by binding to bacterial cell surfaces, including surface proteins, or host proteins such as mucins. The proposed work will use bacteria from the Lactobacillaceae family and a combination of biochemical and analytical methods to establish mechanisms through which metals affect 1) bacterial cell-cell interactions and 2) cell-host interactions between bacteria and host mucin proteins. To test the effects of metals on cell-cell interactions, biochemical and microscopic characterization will be used to measure biofilm formation in single and multi-species systems. Similar techniques will be used to probe cell-mucin interactions in single and multi-species systems. Site-directed mutagenesis will be used to study the role of surface protein metal-binding sites in mediating both cell-cell and cell-host interactions. Collectively, these studies will test the hypothesis that metals can mediate bacterial interactions in gut microbiota by binding to specific cell surface macromolecules and host proteins.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.