Project description:Gene expression analysis of the differentiation process of iPS cells to pancreatic islet cells has revealed that expression of CD82 defines a subset of iPS cell-derived pancreatic endocrine progenitors (EP). While some cell surface proteins such as CD142, CD200 and SUSD2 have been reported as markers of pancreatic progenitor (PP) and EP, CD82+ EP cells are distinct from those PP and EP characterized by the previously identified markers. CD82+ cells isolated from EP cells efficiently differentiated into pancreatic endocrine cells, particularly β cells. Also, CD82+ cells isolated from human cadaver pancreases secreted insulin in response to a high glucose concentration. Furthermore, blocking of CD82 expression by siRNA or inhibition of CD82 in EP by monoclonal antibodies suppressed maturation of β cells, indicating that CD82 plays a role for maturation of EP to β cells. In conclusion, this study identified CD82 not only as a useful marker to isolate β cell precursors but also as an important molecule for functional maturation of β cells.
Project description:This model was reconstructed from single-nucleus RNA-seq (snRNA-seq) data of human postmortem brain and curated using published metabolomics data from human iPSC-derived neurons and cerebrospinal fluid (CSF), together with gene expression data from the Human Protein Atlas. It more accurately simulates human neuronal metabolic flux in neurodegenerative conditions such as Alzheimer's disease (AD).
Project description:We recently found that the tetraspanin family member, CD82, which is aberrantly expressed in chemotherapy-resistant CD34+/CD38− acute myelogenous leukemia (AML) cells, negatively regulates matrix metalloproteinase 9, and plays an important role in enabling CD34+/CD38− AML cells to adhere to the bone marrow microenvironment. This study explored novel functions of CD82 that contribute to AML progression. We employed microarray analysis comparing the gene expression profiles between CD34+/CD38− AML cells transduced with CD82 shRNA and CD34+/CD38− AML cells transduced with control shRNA. Real-time RT-PCR and western blot analysis were performed to examine the effect of CD82 knockdown on the expression of the polycomb group member, enhancer of zeste homolog 2 (EZH2), in leukemia cells. A chromatin immunoprecipitation assay was performed to examine the effect of CD82 expression on the amount of EZH2 bound to the promoter regions of tumor suppressor genes in leukemia cells. We also utilized methylation-specific PCR to examine whether CD82 expression influences the methylation status of the tumor suppressor gene promoter regions in leukemia cells. Microarray analysis revealed that levels of EZH2 decreased after shRNA-mediated depletion of CD82 in CD34+/CD38− AML cells. Moreover, the antibody-mediated blockade of CD82 in leukemia cells lowered EZH2 expression via activation of p38 MAPK signaling, decreased the amount of EZH2 bound to the promoter regions of the tumor suppressor genes, and inhibited histone H3 lysine 27 trimethylation in these promoter regions, resulting in upregulation of the tumor suppressors at both the mRNA and protein levels. The aim of this study was to explore the biological functions of a tetraspanin family protein––CD82–– expressed aberrantly in chemotherapy-resistant CD34+/CD38- acute myelogenous leukemia (AML) cells. Microarray analysis of patient-isolated CD34+/CD38- AML cells revealed that the levels of anti-apoptotic protein BCL2L12 were downregulated after CD82 depletion by specific shRNA. Western blot analysis indicated that BCL2L12 was aberrantly expressed in patient-isolated AML cells and AML cell lines. Furthermore, CD82 blockade by a specific antibody downregulated BCL2L12 in parallel with de-phosphorylation of STAT5 and AKT, while pharmacological inhibition of STAT5 and AKT activation decreased BCL2L12 expression in leukemia cells. In addition, shRNA-mediated downregulation of BCL2L12 increased the levels of cleaved caspase 3and suppressed proliferation of leukemia cells, impairing their engraftment in immunodeficient mice. Taken together, our results indicate that CD82 regulated BCL2L12 expression via STAT5A and AKT signaling and stimulated proliferation and engrafting of leukemia cells, suggesting that CD82 and BCL2L12 may be promising therapeutic targets in AML.
Project description:Myogenic progenitors were isolated by FACS using CD82, ERBB3, and NGFR from human iPSC-derived teratomas and cultured in vitro in the presence of either bFGF, EGF, NGF, or all three growth factors for 4 passages prior to RNA-sequencing.
Project description:The first GSSM of V. vinifera was reconstructed (MODEL2408120001). Tissue-specific models for stem, leaf, and berry of the Cabernet Sauvignon cultivar were generated from the original model, through the integration of RNA-Seq data. These models have been merged into diel multi-tissue models to study the interactions between tissues at light and dark phases.
Project description:We identify the tetraspanin CD82 as the recognition site for xenogeneic endothelial cells independently of Gala1,3-gal structures. We demonstrate that in contrast to undifferentiated cells, differentiated promyelocytic cell lines (HL-60, THP-1 and KG-1) are capable of recognizing xenogeneic porcine endothelial cells in a calcium-dependent manner. We used serial analysis of gene expression (SAGE) to identify the differentially expressed transcripts in these cell lines. Interrogation of these transcripts revealed a number of differentially expressed genes that include the Gala1,3-gal-independent recognition moiety(s). Comparing these SAGE transcripts with those expressed in resting human naive neutrophils identified the tetraspanin CD82 as the most likely candidate responsible for xenogeneic recognition. Blocking antibodies to CD82 in human naive neutrophils inhibited the calcium response and abolished the subsequent Reactive Oxygen Metabolite (ROM) production evoked by the xenogeneic encounter of either Gala1,3-gal knockout or wild-type porcine aortic endothelial cells. Our data identify CD82 on innate immune cells as the major recognition moiety of the xenogeneic endothelium, independently of Gala1,3-gal-structures and open new avenues of intervention to making xenotransplantation a clinical reality.
Project description:We identify the tetraspanin CD82 as the recognition site for xenogeneic endothelial cells independently of Gala1,3-gal structures. We demonstrate that in contrast to undifferentiated cells, differentiated promyelocytic cell lines (HL-60, THP-1 and KG-1) are capable of recognizing xenogeneic porcine endothelial cells in a calcium-dependent manner. We used serial analysis of gene expression (SAGE) to identify the differentially expressed transcripts in these cell lines. Interrogation of these transcripts revealed a number of differentially expressed genes that include the Gala1,3-gal-independent recognition moiety(s). Comparing these SAGE transcripts with those expressed in resting human naive neutrophils identified the tetraspanin CD82 as the most likely candidate responsible for xenogeneic recognition. Blocking antibodies to CD82 in human naive neutrophils inhibited the calcium response and abolished the subsequent Reactive Oxygen Metabolite (ROM) production evoked by the xenogeneic encounter of either Gala1,3-gal knockout or wild-type porcine aortic endothelial cells. Our data identify CD82 on innate immune cells as the major recognition moiety of the xenogeneic endothelium, independently of Gala1,3-gal-structures and open new avenues of intervention to making xenotransplantation a clinical reality. We used serial analysis of gene expression (SAGE) to identify the differentially expressed transcripts in promyelocytic cell lines (HL-60, THP-1 and KG-1) upon differentiation. We looked for genes common to the differentiation pathway in these cell lines but absent from the control naiive neutrophiles.
Project description:There are differences in the expression levels of TCR-related early signaling and cytokines associated with the expression levels of CD81 and CD82. Therefore, we hypothesized that the transcriptome related to T-cell function may also undergo changes.
Project description:Kilian2024 - Immune cell dynamics in Cue-Induced Extended Human Colitis Model
Single-cell technologies such as scRNA-seq and flow cytometry provide critical insights into immune cell behavior in inflammatory bowel disease (IBD). However, integrating these datasets into computational models for dynamic analysis remains challenging. Here, Kilian et al., (2024) developed a deterministic ODE-based model that incorporates these technologies to study immune cell population changes in murine colitis. The model parameters were optimized to fit experimental data, ensuring an accurate representation of immune cell behavior over time. It was then validated by comparing simulations with experimental data using Pearson’s correlation and further tested on independent datasets to confirm its robustness. Additionally, the model was applied to clinical bulk RNA-seq data from human IBD patients, providing valuable insights into immune system dynamics and potential therapeutic strategies.
Figure 4c, obtained from the simulation of human colitis model is highlighted here.
This model is described in the article:
Kilian, C., Ulrich, H., Zouboulis, V.A. et al. Longitudinal single-cell data informs deterministic modelling of inflammatory bowel disease. npj Syst Biol Appl 10, 69 (2024). https://doi.org/10.1038/s41540-024-00395-9
Abstract:
Single-cell-based methods such as flow cytometry or single-cell mRNA sequencing (scRNA-seq) allow deep molecular and cellular profiling of immunological processes. Despite their high throughput, however, these measurements represent only a snapshot in time. Here, we explore how longitudinal single-cell-based datasets can be used for deterministic ordinary differential equation (ODE)-based modelling to mechanistically describe immune dynamics. We derived longitudinal changes in cell numbers of colonic cell types during inflammatory bowel disease (IBD) from flow cytometry and scRNA-seq data of murine colitis using ODE-based models. Our mathematical model generalised well across different protocols and experimental techniques, and we hypothesised that the estimated model parameters reflect biological processes. We validated this prediction of cellular turnover rates with KI-67 staining and with gene expression information from the scRNA-seq data not used for model fitting. Finally, we tested the translational relevance of the mathematical model by deconvolution of longitudinal bulk mRNA-sequencing data from a cohort of human IBD patients treated with olamkicept. We found that neutrophil depletion may contribute to IBD patients entering remission. The predictive power of IBD deterministic modelling highlights its potential to advance our understanding of immune dynamics in health and disease.
This model was curated during the Hackathon hosted by BioMed X GmbH in 2024.