PPG Proteomics and Metabolomics Core B Summary The Proteomics and Metabolomics Core (Core B) provides state-of-the-art instrumentation, methodology, and expertise in analytical proteomics and metabolomics to all investigators in this PPG. A unique feature of the Proteomics and Metabolomics Core is the availability of cutting-edge quantitative proteomics analysis technologies that allows high sensitivity measurements of proteome changes in rodent and ex vivo models of gastric cancer. New services in this renewal application include discovery and targeted metabolomics as well as tissue imaging mass spectrometry (IMS). Core B provides 1) identification and quantitation of proteins in complex samples, 2) analyses of protein modifications, 3) quantitative analyses of lipid and metabolite abundances, 4) quantitative analysis of iron, and 5) molecular imaging of gastric tissue using IMS. Core staff provide consultation on experimental design as well as hands on sample preparation, mass spectrometry analysis, and primary data analysis. Multiple high performance mass spectrometers for LC-MS/MS experiments are available for the proposed analyses. In addition, advanced methods are available including: multidimensional LC-MS/MS for protein identification from complex samples, data-independent acquisition (DIA) for greater proteome coverage, and high spatial and mass resolution imaging methods for tissue analysis with tissue annotation coordinated with Gastric Histopathology Core A. Conversely, Core A will synergize with Core B by using immunohistochemistry to localize protein targets identified by proteomics analysis. Core B also provides relative quantitation using stable isotope differential labeling strategies, such as TMT, for samples derived from animal models, including organoids. Validation of protein expression or metabolite abundance changes is accomplished using targeted multiple reaction monitoring LC-MS/MS methods. Project 1 (Peek) will utilize metabolomics methods to measure metabolite changes in H. pylori strains 1) treated in vitro with deoxycholic acid (DCA) or 2) isolated from mice treated with DCA, as well as IMS methods to localize bile acids in H. pylori-infected gastric tissues. Project 2 (Wilson) will utilize proteomic analyses to measure changes in patient-derived gastric organoids infected with H. pylori and treated with SMOX inhibitors and electrophile scavengers. Metabolomics will also be used to measure metabolite changes in infected and treated mouse gastric tissue. Project 3 (Cover) will employ metabolomics methods to examine metabolite changes in a gerbil model in response to dietary factors that predispose to gastric cancer. Project 3 will also utilize IMS methods to measure changes in metabolites, proteins, and lipids in gastric tissue in a spatially-resolved manner in animal models and in human tissue microarrays. In addition, Project 3 will use elemental analysis methods to measure iron uptake in H. pylori as a function of e...