Project description:Myocardial infarction (MI) results from occlusion of blood supply to the heart muscle causing death of cardiac muscle cells. Following myocardial infarction (MI), scar formation acts to mechanically stabilise the injured heart to prevent rupture and death. While fibroblasts and macrophages are implicated in post-MI scar formation and maturation, their exact contributions to this process are poorly characterised, especially in the long-term (i.e., beyond 1-week post-MI). Here, we employ state-of-the-art spatially-targetted optical micro-proteomics (STOMP) to isolate proteomes of tissue fractions enriched for fibroblasts (sma+) and macrophages (cd68+) over a 6-week post-MI timecourse and compare them to whole-scar proteome. We illustrate dynamic, specific changes in sma- and cd68-enriched fraction protein composition over 1-6 weeks post-MI with some of these changes reflected in whole-infarct preparations. These results link specific cell populations to specific protein changes in whole infarct.
Project description:HIV-1 spreads between CD4 T cells most efficiently through virus-induced cell-cell contacts. To test whether this process potentiates viral spread by activating signaling pathways we developed an approach to analyze the phosphoproteome in infected and uninfected mixed population T cells using differential metabolic labeling and mass spectrometry. We discovered HIV-1 induced activation of signaling networks during viral spread encompassing over 200 cellular proteins. Strikingly, pathways downstream of T cell receptor were the most significantly activated, despite the absence of canonical antigen dependent stimulation. The importance of this pathway was demonstrated by depletion of proteins and we show that HIV-1 Env mediated cell-cell contact, T cell receptor and the Src kinase Lck were essential for signaling dependent enhancement of viral dissemination. This study demonstrates that manipulation of signaling at immune cell contacts by HIV-1 is essential for promoting virus replication and defines a new paradigm for antigen independent T cell signaling.
Project description:We focus on the characterization of proteins in the nuclear environment of β-cells after brief, high glucose-stimulation. We compared purified nuclei derived from β-cells stimulated with 17mM glucose for 0, 2, and 5 minutes using quantitative proteomics, a time frame that most likely does not result in translation of new protein in the cell.
Project description:Samples-WT Basal condition primary cortex cells; WT B27 Starved-Primary cortex cells starved overnight without B27 supplement media. WT AA Starved-Primary cortex cell starved without amino acid for 2 hours. WT AA Refed-Primary cortex cell refed for 1 hour after amino acid starvation. KO Basal-SLC38 Knockout Primary cortex cells starved overnight without B27 supplement media. KO B27 Starved-SLC38 Knockout Primary cortex cell starved without amino acid for 2 hours. KO AA starved-SLC38 Knockout Primary cortex cell refed for 1 hour after amino acid starvation. KO AA Refed-SLC38 Knockout Primary cortex cell refed for 1 hour after amino acid starvation.
Project description:To better understand proteostasis in health and disease, determination of protein half-lives is essential. We improved the precision and accuracy of peptide-ion intensity based quantification in order to enable accurate determination of protein turnover in non-dividing cells using dynamic-SILAC. This enabled precise and accurate protein half-life determination ranging from 10 to more than 1000 hours. We achieve good proteomic coverage ranging from four to six thousand proteins in several types of non-dividing cells, corresponding to a total of 9699 unique proteins over the entire dataset. Good agreement was observed in half-lives between B-cells, natural killer cells and monocytes, while hepatocytes and mouse embryonic neurons showed substantial differences. Our comprehensive dataset enabled extension and statistical validation of the previous observation that subunits of protein complexes tend to have coherent turnover. Furthermore, we observed complex architecture dependent turnover within complexes of the proteasome and the nuclear pore complex. Our method is broadly applicable and might be used to investigate protein turnover in various cell types.
Project description:To better understand proteostasis in health and disease, determination of protein half-lives is essential. We improved the precision and accuracy of peptide-ion intensity based quantification in order to enable accurate determination of protein turnover in non-dividing cells using dynamic-SILAC. This enabled precise and accurate protein half-life determination ranging from 10 to more than 1000 hours. We achieve good proteomic coverage ranging from four to six thousand proteins in several types of non-dividing cells, corresponding to a total of 9699 unique proteins over the entire dataset. Good agreement was observed in half-lives between B-cells, natural killer cells and monocytes, while hepatocytes and mouse embryonic neurons showed substantial differences. Our comprehensive dataset enabled extension and statistical validation of the previous observation that subunits of protein complexes tend to have coherent turnover. Furthermore, we observed complex architecture dependent turnover within complexes of the proteasome and the nuclear pore complex. Our method is broadly applicable and might be used to investigate protein turnover in various cell types.
Project description:To better understand proteostasis in health and disease, determination of protein half-lives is essential. We improved the precision and accuracy of peptide-ion intensity based quantification in order to enable accurate determination of protein turnover in non-dividing cells using dynamic-SILAC. This enabled precise and accurate protein half-life determination ranging from 10 to more than 1000 hours. We achieve good proteomic coverage ranging from four to six thousand proteins in several types of non-dividing cells, corresponding to a total of 9699 unique proteins over the entire dataset. Good agreement was observed in half-lives between B-cells, natural killer cells and monocytes, while hepatocytes and mouse embryonic neurons showed substantial differences. Our comprehensive dataset enabled extension and statistical validation of the previous observation that subunits of protein complexes tend to have coherent turnover. Furthermore, we observed complex architecture dependent turnover within complexes of the proteasome and the nuclear pore complex. Our method is broadly applicable and might be used to investigate protein turnover in various cell types.
Project description:Transcriptional profiling of XiGFP Epiblast Stem Cells (EpiSCs) overexpressing Klf2, Prdm14, Prdm14+Klf2, or vector control. Cells cultured in activin and bFGF (day 0) or on day 2 and day 4 after transfer to serum and LIF on feeder cells and sorting for dsRed expression to remove feeder cells.