Project description:Transcriptional analysis of immunological characteristics of petstore mice, C57Bl/6 laboratory mice, and C57Bl/6 laboratory mice cohoused with petstore. We hypothesized that cohousing would confer a basal transcriptional signature of immune activation to laboratory mice from petstore mice. Comparison of these data with existing human adult vs. neonatal PBMC expression profiling data (GSE27272) revealed close concordance of laboratory mice with human neonates, and of cohoused or petstore mice with human adults. Results highlight the impact of environment on the basal immune state and suggest that restoring physiological microbial exposure in laboratory mice could provide a relevant tool for modeling immunological events in free-living organisms, including humans.
Project description:Filter-Aided Sample Preparation (FASP) is a well-established method in proteomics, yet its potential for the parallel recovery of metabolites remains largely unexplored. Herein, we evaluate the performance of FASP as a straightforward workflow for the simultaneous isolation of protein and corresponding metabolite fractions from a single urine sample. The FASP-based LC-MS/MS approach for both proteomics and metabolomics analysis identified 3,163 non-redundant peptides corresponding to 957 unique protein groups. The metabolomic profile comparison of three urine fractions, specifically FASP-concentrated, FASP flow-through, and raw samples, resulted in the identification of 176 common metabolites. Next, as a proof-of-concept, the FASP protocol was applied to compare the metabolomic profiles of clinical urine samples from healthy individuals (n=13) and patients with Ta bladder cancer (n=12). The metabolomic modulation was consistent with previously reported findings, highlighting perturbations in phenylacetate, purine, and tryptophan metabolism, as reflected by changes in metabolites such as adenosine monophosphate (AMP), phenylacetic acid, glutamine, cytosine, and L-tryptophan. FASP protocol can be effectively adapted for the concurrent profiling of both proteomic and metabolomic fractions from urine samples. Thus, FASP-based workflow represents a viable alternative for single-step sample preparation, facilitating subsequent quantitative multi-omics data integration.
Project description:The rapid pace of bacterial evolution enables organisms to adapt to the laboratory environment with repeated passage and thus diverge from naturally-occurring environmental (“wild”) strains. Distinguishing wild and laboratory strains is clearly important for biodefense and bioforensics; however, DNA sequence data alone has thus far not provided a clear signature, perhaps due to lack of understanding of how diverse genome changes lead to convergent phenotypes, difficulty in detecting certain types of mutations, or perhaps because some adaptive modifications are epigenetic. Monitoring protein abundance, a molecular measure of phenotype, can overcome some of these difficulties. We have assembled a collection of Yersinia pestis proteomics datasets from our own published and unpublished work, and from a proteomics data archive, and demonstrated that protein abundance data can clearly distinguish laboratory-adapted from wild. We developed a lasso logistic regression classifier that uses binary (presence/absence) or quantitative protein abundance measures to predict whether a sample is laboratory-adapted or wild that proved to be ~98% accurate, as judged by replicated 10-fold cross-validation. Protein features selected by the classifier accord well with our previous study of laboratory adaptation in Y. pestis. The input data was derived from a variety of unrelated experiments and contained significant confounding variables. We show that the classifier is robust with respect to these variables. The methodology is able to discover signatures for laboratory facility and culture medium that are largely independent of the signature of laboratory adaptation. Going beyond our previous laboratory evolution study, this work suggests that proteomic differences between laboratory-adapted and wild Y. pestis are general, potentially pointing to a process that could apply to other species as well. Additionally, we show that proteomics datasets (even archived data collected for different purposes) contain the information necessary to distinguish wild and laboratory samples. This work has clear applications in biomarker detection as well as biodefense.
Project description:This is a prospective, multi-centered study to assess whether urine metabolomics can play a role in the screening of colorectal cancer (CRC). Urine samples will be collected from 1000 patients going through an established CRC screening program, and from a further 500 patients who already have a diagnosis of CRC. Using nuclear magnetic resonance (NMR) spectroscopy, the 1H NMR spectrum of urine samples will be analyzed for specific metabolites, and establish the metabolomic signature of colorectal cancer. The results from metabolomic urinalysis of this screening cohort will be compared with results from colonoscopy, histological descriptions, fecal occult blood testing (FOBT), and fecal immune testing (FIT) to assess the accuracy of urine metabolomics in identifying patients with polyps and malignancies. The urine metabolomic results from the colorectal cancer group will be correlated with operative, histological and clinical staging to define the role of urine metabolomics in assessing colorectal cancer type, location and stage. Additionally approximately 300 urine samples from breast cancer patients and 300 from prostate cancer patients will be collected to validate that the colorectal cancer signature is unique.