Project description:In this study, we developed and optimized a nanoproteomic workflow that we termed Nanogram TMT Processing in One Tube (NanoTPOT). Through the assessment of proteolytic digestion, tandem mass tag (TMT) labeling, online and offline frac-tionation strategies, our optimized workflow effectively eliminated the need for sample desalting and enabled compatible sample processing for MS analysis. We further applied the NanoTPOT workflow to examine cellular response to stress caused by dithiothreitol in Hela cells, where we identified and quantified 6935 proteins in a TMT 10-plex experiment with one microgram of starting material in each channel.
Project description:Assessment of technical error in a dual-channel, two timepoint experiment using White lab Drosophila melanogaster microarrays Keywords: repeat sample
Project description:Purpose: The goal of this study is to integrate NGS-derived parotid salivary gland transcriptome profiling (RNA-seq) to metabolomics (UPLC-MS/MS) methods and identify mechanisms driving radiation-induced xerostomia, with potential clinical application to head and neck cancer patients. Methods: Parotid salvary gland mRNA profiles of 28-day-old wild-type (WT) and 5 Gy radiation treated mice were generated by deep sequencing, in triplicate, using Illumina TruSeq. The sequenced reads that passed quality filters were trimmed with Trimmomatic, mapped to mm10 genome with HISAT2, and summarized at the gene level with HTSeq-count and analyzed with DESeq2. Results: Using an optimized data analysis workflow, we mapped sequenced reads per sample to the mouse genome (build mm10) and identified 25422 genes with at least 1 read in the parotid glands of WT and radiation treated mice with HISTA2 workflow. RNA-seq data QA/QC by Principal Component Analysis showed a clear separation between conditions. 155 genes showed significant differential expression between the WT and radiation treated salivary gland, with an adjsuted p-value < 0.05. Pre ranked Gene Set Enrichment Analysis against the CPDB database led to 859 altered pathways with a p-value < 0.05. Integrative analysis pointed to 103 RNA-Seq/Metabolite joint enriched pathways with a p-value < 0.05.
Project description:The interplay between pathogens and hosts has been studied for decades using targeted approaches such as the analysis of mutants and host immunological responses. Although much has been learned from such studies, they focus on individual pathways and fail to reveal the global effects of infection on the host. To alleviate this issue, high-throughput methods such as transcriptomics and proteomics have been used to study host-pathogen interactions. Recently, metabolomics was established as a new method to study changes in the biochemical composition of host tissues. We report a metabolomics study of Salmonella enterica serovar Typhimurium infection. We used Fourier Transform Ion Cyclotron Resonance Mass Spectrometry with Direct Infusion to reveal that dozens of host metabolic pathways are affected by Salmonella in a murine infection model. In particular, multiple host hormone pathways are disrupted. Our results identify unappreciated effects of infection on host metabolism and shed light on mechanisms used by Salmonella to cause disease, and by the host to counter infection. Female C57BL/6 mice were infected with Salmonella enterica serovar Typhimurium SL1344 cells by oral gavage. Feces and livers were collected and metabolites extracted using acetonitrile. For experiments with feces, samples were collected from 4 mice before and after infection. For liver experiments, 11 uninfected and 11 infected mice were used. Samples were combined into 3 groups of 3-4 mice each, resulting in the analysis of 3 group samples of uninfected and 3 of infected mice. Extracts were infused into a 12-T Apex-Qe hybrid quadrupole-FT-ICR mass spectrometer equipped with an Apollo II electrospray ionization source, a quadrupole mass filter and a hexapole collision cell. Raw mass spectrometry data were processed as described elsewhere (Han et al. 2008. Metabolomics. 4:128-140 [PMID 19081807]). To identify differences in metabolite composition between uninfected and infected samples, we filtered the list of masses for metabolites which were present on one set of samples but not the other. Additionally, we calculated the ratios between averaged intensities of metabolites from uninfected and infected mice. To assign possible metabolite identities, monoisotopic neutral masses of interest were queried against MassTrix (http://masstrix.org). Masses were searched against the Mus musculus database within a mass error of 3 ppm. Data were analyzed by unpaired t tests with 95% confidence intervals.
Project description:Molecular networking connects mass spectra of molecules based on the similarity of their fragmentation patterns. However, during ionization, molecules commonly form multiple ion species with different fragmentation behavior. As a result, the fragmentation spectra of these ion species often remain unconnected in tandem mass spectrometry-based molecular networks, leading to redundant and disconnected sub-networks of the same compound classes. To overcome this bottleneck, we develop Ion Identity Molecular Networking (IIMN) that integrates chromatographic peak shape correlation analysis into molecular networks to connect and collapse different ion species of the same molecule. The new feature relationships improve network connectivity for structurally related molecules, can be used to reveal unknown ion-ligand complexes, enhance annotation within molecular networks, and facilitate the expansion of spectral reference libraries. IIMN is integrated into various open source feature finding tools and the GNPS environment. Moreover, IIMN-based spectral libraries with a broad coverage of ion species are publicly available.