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Bacterial modulators of metazoan lipogenesis

后生动物脂肪生成的细菌调节剂

基本信息

批准号：
9376448
负责人：
Amy Karol Walker
金额：
$ 25.13万
依托单位：
UNIV OF MASSACHUSETTS MED SCH WORCESTER
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-08-01 至 2019-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9376448
关键词：
Address Affect Animal Model Animals Automobile Driving B-Lymphocytes Bacteria Binding Proteins Biological Assay Butyrates Caenorhabditis elegans Cell Culture Techniques Cell Line Cell physiology Cells Cellular Metabolic Process Cholesterol Citrates Coenzyme A Communication Complex Cultured Cells Data Defect Development Dietary Fiber Digestion Disease Dissection Escherichia coli Family member Fatty Acids Fatty acid glycerol esters Food Gene Expression Genes Genetic Genetic Models Genetic Transcription HMGB1 Protein Harvest Health Human Immune Immune response Immune signaling Immune system Immunity Immunologic Markers Individual Inflammation Innate Immune Response Intestines Knowledge Link Lipids Mammalian Cell Mammals Membrane Metabolic Metabolic Diseases Metabolic Pathway Metabolism Modeling Mus Mutation Non-Insulin-Dependent Diabetes Mellitus Nutrient Organ Pathogenicity Pathologic Pathway interactions Peripheral Phospholipids Physiological Physiology Process Proliferating Propionates Protein Family Proteolytic Processing Pyruvate Regulation Regulatory Element Regulatory Pathway Reporter Reporting Response Elements Signal Transduction Sterols Structure Succinates System Testing Therapeutic Effect Tissues Visual Vitamin B 12 Vitamins Volatile Fatty Acids Walkers desaturase experimental study gene synthesis genome-wide gut microbiota immune function innovation insight lipid biosynthesis lipid metabolism liver function microbial microbial community microbiota microorganism mutant programs propionyl-coenzyme A residence response tissue processing transcription factor

项目摘要

Project Summary Bacteria live in our gut, acting as agents for food digestion, producing essential vitamins and conversing with our immune systems to permit residence in our tissues. This “communication” occurs as the metabolites produced by the bacteria interact with our cells, changing signaling responses and transcriptional mechanisms. Although current studies have profiled many bacterial species living in our gut and linked them to a wide variety of normal or pathological physiological states, these studies of complex microbiota can not tell us how the individual bacterial products change our cellular function. Without this knowledge, we can't understand which cellular pathways are targeted, or what the effects of therapeutics that mimic or block bacterial responses would be. To address this open, critical question, we have paired two genetic models, C. elegans and E. coli, to determine which bacterial pathways affected fat accumulation in the host. C. elegans consume bacteria, but many of the microorganisms remain intact, reside and proliferate in the gut, similar to mammals. Using a visual screen in C. elegans, we found that multiple E. coli mutants deficient in the methylcitrate cycle, which converts propionate to pyruvate or succinate, stimulate a lipogenic reporter. This gene, the sterol Co-A desaturase (SCD1) fat-7, is conserved to humans, as is its regulation by the sterol response element binding protein (SREBP) family of transcription factors. Short chain fatty acids (SCFAs) such as propionate have been implicated as bacterial products influencing host responses. Strikingly, we found propionate also induces SCD expression in human intestine-derived cell lines. We will use C. elegans determine the mechanisms that link propionate to lipogenic gene expression, testing if this requires SREBPs, along with other transcription factors, then expand these studies to mammalian cell culture. Metabolic disease is often linked to two “hits”: lipogenesis and immune function. We previously found that a conserved metabolic pathway increasing fat-7 in C. elegans also stimulated innate immune responses. Therefore, we will also determine if propionate changes immune function in C. elegans and in mammalian cells. Use of C. elegans allows a rapid genetic dissection of lipogenic and immune responses, identifying regulatory pathways in the context of a whole animals model. Our next steps, evaluating these high confidence models in human cells, confirms relevance to mammals and, importantly, allows us to examine these interactions in the more complex mammalian context.

项目总结