"Optogenetic control of amyloid beta protective gene expression in the C. elegans gut microbiota"

“线虫肠道微生物群中β淀粉样蛋白保护性基因表达的光遗传学控制”

• 批准号: 9228069
• 负责人: Jeffrey Jay Tabor
• 金额: $ 25.04万
• 依托单位: RICE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9228069
• 关键词: Acute; Affect; Age; Alzheimer' s Disease; Amyloid; Amyloid beta-Protein; Animals; Area; Bacteria; Bacterial Genes; Binding; Biological Process; Brain; Caenorhabditis elegans; Cardiovascular Diseases; Cause of Death; Cellular biology; Chemicals; Chronic Disease; Communities; Cyanobacterium; Degenerative Disorder; Dementia; Diabetes Mellitus; Diet; Digestion; Dimensions; Disease; Drosophila genus; Energy-Generating Resources; Engineering; Escherichia coli; Event; Exhibits; Future; Gastrointestinal tract structure; Gene Expression; Genes; Genetic; Goals; Human; Immune system; Impaired cognition; In Vitro; Infant; Infection; Knowledge; Lead; Life; Light; Link; Liver diseases; Malignant Neoplasms; Mammals; Methodology; Microbe; Modeling; Molecular; Mus; Nematoda; Neurodegenerative Disorders; Neurosciences; Organism; Pathology; Pattern; Photoreceptors; Polysaccharides; Prevention; Production; Public Health; Research; Research Personnel; Senile Plaques; Signal Transduction; Societies; Study models; System; Technology; Therapeutic; Transgenic Organisms; United States National Institutes of Health; Variant; Work; Zebrafish; abeta accumulation; abeta toxicity; abstracting; age related; aged; behavioral impairment; colanic acid; effective therapy; extracellular; feeding; gut microbiota; healthy aging; improved; in vivo; microbiome; microbiota; optogenetics; pathogen; prevent; protein-histidine kinase; synthetic biology

Project Summary/Abstract Aggregation of amyloid-β (Aβ) into plaques is a hallmark of AD and considered a primary event in AD pathologies. Transgenic variants of the rapidly reproducing nematode C. elegans expressing human Aβ accumulate aggregates with age and exhibit early lethality. C. elegans feed on E. coli bacteria, 10% of which escape digestion and constitute the gut microbiota. Due to the high genetic tractability of both host and microbe, C. elegans and E. coli provide a powerful model for studying the molecular mechanisms of gut microbiota-host interactions. In exciting preliminary work, co-investigator Wang has identified 14 E. coli genes that protect against Aβ induced lethality in transgenic C. elegans. We have determined that four are linked to production of the extracellular polysaccharide Colanic Acid (CA). Furthermore, we have shown that pure CA protects against Aβ toxicity when delivered with live bacteria. The next step is to identify the mechanism by which CA and the remaining 10 genes protect against Aβ toxicity. Such results would inform future studies in mammals and the engineering of therapeutic bacteria that prevent or treat AD. The major current limitation in studying the mechanisms of gut microbiota-host interactions is the lack of technologies for externally manipulating bacterial gene expression in vivo. Traditional chemical effectors of bacterial gene expression are insufficient due to complications arising from delivery, transport, and degradation. Optogenetics is a rapidly advancing technology combining light and genetically-encoded photoreceptors to control molecular biological processes in live organisms. Light can be controlled with exquisite precision in the wavelength, intensity, spatial, and temporal dimensions, affording unmatched levels of control. Previously, P.I. Tabor has transported light sensing two-component histidine kinase signal transduction systems from cyanobacteria into E. coli, and used them for unprecedented quantitative, spatial and temporal control of gene expression in vitro. The goal of this proposal is to combine P.I. Tabor's and co-I Wang's methodologies to characterize how gut bacterial gene expression affects Aβ toxicity in the C. elegans model. We will achieve this goal through two Specific Aims: Demonstrate precise optogenetic control of the expression of E. coli genes that protect against Aβ toxicity in the gut of live C. elegans (Aim 1), and characterize the relationships between the quantitative, spatial and temporal pattern of the expression of E. coli genes in the gut and the amelioration of Aβ toxicity (Aim 2). By achieving these aims, we will demonstrate the first optogenetic control of microbiota function in a live animal. This proposed research will directly improve scientific knowledge in gut microbiota-host interactions, and molecular mechanisms of AD pathologies. Optogenetics has revolutionized neuroscience, and is now enabling major breakthroughs in cell biology and systems and synthetic biology. The research proposed here will bring optogenetics to the fundamental and timely problem of the microbiome.

项目总结/摘要 β淀粉样蛋白（Aβ）聚集成斑块是AD的一个标志，被认为是AD的主要事件 病理学。快速繁殖线虫C.表达人Aβ的线虫 随着年龄的增长聚集并表现出早期致死性。C.线虫以E.大肠杆菌，其中10% 逃避消化并构成肠道微生物群。由于宿主和寄主的高度遗传可塑性， microbe，C. elegans和E.大肠杆菌为研究肠道致病的分子机制提供了一个强有力的模型 微生物与宿主的相互作用在令人兴奋的初步工作中，共同研究者王已经确定了14个E。杆菌基因 保护转基因C.优美的我们已经确定有四个与 生产胞外多糖可乐酸（CA）。此外，我们还证明了纯CA 当与活细菌一起递送时，可防止Aβ毒性。下一步是通过以下方式确定机制： CA和其余10个基因保护免受Aβ毒性。这些结果将为未来的研究提供信息， 哺乳动物和预防或治疗AD的治疗性细菌的工程化。 目前研究肠道微生物与宿主相互作用机制的主要局限是缺乏 体外操纵细菌基因表达的技术。传统的化学效应物 细菌基因表达不足，这是由于递送、运输和 降解光遗传学是一项快速发展的技术，结合了光和基因编码的 光感受器来控制活生物体中的分子生物学过程。灯光可以控制， 在波长、强度、空间和时间维度上的精密度， 控制力此前，P.I.塔博尔已转运光敏双组分组氨酸激酶信号 从蓝藻到E.大肠杆菌，并使用它们进行前所未有的定量，空间 和体外基因表达的时间控制。该提案的目标是联合收割机P.I.塔博尔和co-I Wang的方法来表征肠道细菌基因表达如何影响C. elegans 模型我们将通过两个具体目标实现这一目标： 表达E.大肠杆菌基因，在活的C. elegans（Aim 1），以及 描述表达的数量、空间和时间模式之间的关系 大肠大肠杆菌基因在肠道和Aβ毒性的改善（目的2）。 通过实现这些目标，我们将在一个实验室中展示微生物群功能的第一个光遗传学控制。 活的动物。这项研究将直接提高肠道微生物宿主的科学知识 相互作用和AD病理学的分子机制。光遗传学彻底改变了神经科学， 并且正在细胞生物学、系统和合成生物学领域取得重大突破。研究 这里提出的将把光遗传学带到微生物组的根本和及时的问题。