Project description:Single cell transcriptomic analyses (scRNAseq) of hepatocytes and liver endothelial cells (L-EC) have revolutionized the understanding of the spatial architecture of liver structure and function. The spatial alignment of L-EC and hepatocytes is pivotal for liver function in health and disease given that L-EC act as instructive gatekeeper of nearby hepatocytes including the maintenance of liver metabolic zonation in a Wnt-dependent manner. Advancing liver biology beyond the ’transcript-centric’ view of scRNAseq analyses is presently restricted by the limited resolution of proteomics and genome-wide techniques to analyse post-translational modifications. Here, by combining spatial cell sorting methodology with transcriptomic and quantitative proteomic/phospho-proteomic analyses, we established the first functionally and spatially-resolved proteome landscape of the liver endothelium, yielding deep mechanistic insight into zonated vascular signalling mechanisms. Phosphorylation of receptor tyrosine kinases (RTK) was detected preferentially in the central vein area resulting in an atypical enrichment of tyrosine phosphorylation. Prototypic biological validation of the identified strong phosphorylation gradient of the vascular RTK Tie1 by blockade resulted in the rapid peri-central dysregulation of the L-EC transcriptome. Notably, the expression of Wnt9b in L-EC was discovered as Tie receptor controlled with reciprocal regulation by FoxO1 and STAT3 transcription factors. Genetic inactivation of Tie1 in L-EC or antibody blockade resulted in reduced liver regeneration following partial hepatectomy with reduced Wnt ligand and Wnt target gene expression, including Sox9, Tbx3 and Lgr5. Taken together, the study has yielded unparalleled insight into the spatial organization of L EC signalling and discovered a vascular Tie/Wnt signalling axis as regulator of liver function. The employed spatial sorting technique followed by phospho-proteomic analysis may be employed as a universally adaptable strategy for the spatial phosphoproteomic analysis of scRNAseq data-defined relevant cellular (sub)-populations.
Project description:Transcriptomic, proteomic and phosphoproteomic underpinnings of daily exercise performance and Zeitgeber activity of endurance training in mouse skeletal muscle
Project description:Desmoplastic small round cell tumor (DSRCT) is an aggressive malignancy that occurs predominantly in young adult males and is characterized by abdominopelvic sarcomatosis exhibiting multi-lineage cellular nests of epithelial, muscular, mesenchymal, and neural differentiation admixed with desmoplastic stroma. Prior to the recognition of the disease as a distinct clinical entity, DSRCT was invariably misclassified as poorly differentiated atypical cancer of the testes, ovary, mesentery, or gastrointestinal tract, and the chemotherapies used for those malignancies elicited poor clinical response. As previously reported, a tectonic shift in the treatment of these patients occurred after researchers made two astute observations: 1) DSRCT microscopically resembles other small round “blue cell” sarcoma subtypes (e.g., ES, rhabdomyosarcoma, synovial sarcoma), and 2) DSRCT and ES have the same N-terminal EWSR1 fusion partner. Proteomic analysis using a reverse-phase protein lysate array (RPPA) was used to elucidate biomarkers that distinguish DSRCT from adjacent normal tissue and Ewing sarcoma. This proteomic analysis revealed novel proteins, such as the androgen receptor and Syk, that may be susceptible to drug targeting, as well as oncogenic pathways like Akt-PI3K that are highly expressed in DSRCT.
Project description:Study purpose: to explore the entire spectrum of proteomic and genomic changes (amongst others) involved in diseases and in healthy/control populations. The Study is designed to discover biomarkers, develop and validate diagnostic assays, instruments and therapeutics as well as other medical research. Specifically, researchers may analyze proteins, RNA, DNA copy number changes, including large and small (1,000-100,000 kb) scale rearrangements, transcription profiles, epigenetic modifications, sequence variation, and sequence in both diseased tissue and case-matched germline DNA from Subjects.
Project description:Aberrant signaling pathway activity is a hallmark of tumorigenesis and progression, which has guided targeted inhibitor design for over 30 years. Yet, adaptive resistance mechanisms, induced by rapid, context-specific signaling network rewiring, continue to challenge therapeutic efficacy. By leveraging progress in proteomic technologies and network-based methodologies over the past decade we developed VESPA—an algorithm designed to elucidate mechanisms of cell response and adaptation to drug perturbations—and used it to analyze 7-point phosphoproteomic time series from colorectal cancer cells treated with clinically-relevant inhibitors and control media. Interrogation of tumor-specific enzyme/substrate interactions accurately inferred kinase and phosphatase activity, based on their inferred substrate phosphorylation state, effectively accounting for signal cross-talk and sparse phosphoproteome coverage. The analysis elucidated time-dependent signaling pathway response to each drug perturbation and, more importantly, cell adaptive response and rewiring that was experimentally confirmed by CRISPRko assays, suggesting broad applicability to cancer and other diseases.
Project description:Therapeutic neo-vasculogenesis in vivo can be achieved by the co-transplantation of human endothelial colony-forming progenitor cells (ECFCs) with mesenchymal stem/progenitor cells (MSPCs).The underlying mechanism is not completely understood thus hampering the development of novel stem cell therapies.We hypothesized that proteomic profiling could be used to retrieve the in vivo signaling signature during the initial phase of human neo-vasculogenesis. ECFCs and MSPCs were therefore either transplanted alone or co-transplanted subcutaneously into immune deficient mice. Early cell signaling, occurring within the first 24 hours in vivo, was analyzed using antibody microarray proteomic profiling.Vessel formation and persistence were verified in parallel transplants for up to 24 weeks. Proteomic analysis revealed significant alteration of regulatory components including caspases, calcium/calmodulin-dependent protein kinase, DNA protein kinase,human ErbB2 receptor-tyrosine kinase as well as mitogen-activated protein kinases.Therapeutic candidate caspase-4 was selected from array results for targeting vascular network formation in vitro as well as modulating therapeutic vasculogenesis in vivo. As a proof-of-principle, caspase-4 and general caspase-blocking led to diminished endothelial network formation in vitro and significantly decreased vasculogenesis in vivo. Proteomic profiling ex vivo thus unraveled a signaling signature which can be targeted to modulate neo-vasculogenesis in vivo.
Project description:Study objectives: Acute sleep deprivation affects both central and peripheral biological processes. Prior research has mainly focused on specific proteins or biological pathways that are dysregulated in the setting of sustained wakefulness. This pilotexploratory study’s objective wasaimed to provide a comprehensive view of the biological processes and proteins impacted by acute sleep deprivation in both plasma and cerebrospinal fluid (CSF). Methods: We collected plasma and CSF from human participants during one night of sleep deprivation and control normal sleep conditions. 1300 proteins were measured at hour 0 and hour 24 using a high-scale aptamer-based proteomics platform (SOMAomascan) and a systematics biological database tool (Metascape) was used to reveal dysregulated biological pathways. Results: Acute sleep deprivation lead to opposite effects in plasma and CSF, decreasingdecreased the number of upregulated and downregulated differential protein expression and biological pathways and proteins in plasma but increased upregulated and downregulated protein and biological pathwayssing them in CSF. Predominantly affected pProteins and n pathways were associated with that were predominantly affected by sleep deprivation included immune response, inflammation, phosphorylation, membrane signaling, cell-cell adhesion, and extracellular matrix organization. Conclusions: The identified modification across biofluids adds to evidence that acute sleep deprivation has important impacts on biological pathways and proteins that can negatively affect human health. As a hypothesis-driving study, these findings may help with the exploration of novel mechanisms that mediate sleep loss and associated conditions, drive the discovery of new sleep loss biomarkers, and ultimately aid in the identification of new targets for intervention to human diseases.