Project description:We performed 3 single-cell RNAseq experiments to dissect the postnatal islet heterogeneity. In order to reach our goal, we used the Fltp lineage tracing (FltpiCre mTmG) mouse line. Thus we used mice at the age of 16 days, isolated islets of Langerhans from them and sorted via flow cytometry the three Fltp subpopulations.
Project description:Pancreatic acinar cells can dedifferentiate upon tissue injury and acquire ductal characteristics. This acquisition of duct cell features is critical in tumor development. Nevertheless, duct cells themselves are less prone for development of PDAC (pancreatic ductal adenocarcinoma) than dedifferentiated acini. We aimed to clarify which genes are unique for dedifferentiated acini. Mixed exocrine preparations of acinar and duct cells were obtained from human pancreatic donor organs and cultured to induce dedifferentiation. We lineage-labeled and FACS-purified these human dedifferentiated acinar cells and compared them to duct cells from the same donor (n=5).
Project description:Transcriptional profiling of a directed differentiation time course converting human embryonic stem cells (hES) into immature pancreatic beta cell precursors.
Project description:miRNA transcript profiling of a directed differentiation time course converting human embryonic stem cells (hES) into immature pancreatic beta cell precursors.
Project description:Expansion of beta cells from the limited number of adult human islet donors is an attractive prospect for increasing cell availability for cell therapy of diabetes. However, while evidence supports the replicative capacity of adult beta cells in vivo, attempts at expanding human islet cells in tissue culture resulted in loss of beta-cell phenotype. Using a genetic lineage-tracing approach we have provided evidence for massive proliferation of beta-cell-derived (BCD) cells within these cultures. Expansion involves dedifferentiation resembling epithelial-mesenchymal transition (EMT). Epigenetic analyses indicate that key beta-cell genes maintain a partially open chromatin structure in expanded BCD cells, although they are not transcribed. Here we report that BCD cells can be induced to redifferentiate by a combination of soluble factors. The redifferentiated cells express beta-cell genes, store insulin in typical secretory vesicles, and release it in response to glucose. The redifferentiation process involves mesenchymal-epithelial transition, as judged from changes in gene expression. Moreover, inhibition of the EMT effector SLUG using shRNA results in stimulation of redifferentiation. BCD cells also give rise at a low rate to cells expressing other islet hormones, suggesting transition through an islet progenitor-like stage during redifferentiation. These findings suggest that ex-vivo expansion of adult human islet cells is a promising approach for generation of insulin-producing cells for transplantation, as well as basic research, toxicology studies, and drug screening. Gene expression was studied in unexpanded islets (4 donors), expanded and dedifferentiated islet cells (4 donors), and re-differentiated islet cells (3 donors). The experiment was performed in 3 batches (see Date in the description table below).
Project description:This submission comprises RNA-Seq profiling of in vivo differentiated pancreatic beta cells types and primary islet-derived pancreatic beta cell sources. The study reports that re-aggregation of immature beta-like cells (d20Beta) and removal of progenitor cells leads to further maturation in vitro resulting in beta-cells (eBCBeta) that are closer to human primary islet-derived beta-cells(IsletBeta). As a control stem cell derived spheres were dissocated, reassociated and taken through till the end of the protocol (NECBeta).
Project description:Insulin-producing beta cells become dedifferentiated during diabetes progression. An impaired ability to select substrates for oxidative phosphorylation, or metabolic inflexibility, sets the stage for progression from beta cell dysfunction to beta cell dedifferentiation. In this study, we sought to isolate and functionally characterize failing beta cells, as a preliminary step to identify pathways to reverse dedifferentiation. Using various experimental models of diabetes, we found a striking enrichment in the expression of aldehyde dehydrogenase 1 isoform A3 (ALDH+) as beta cells become dedifferentiated. Flow-sorted ALDH+ islet cells demonstrate impaired glucose-induced insulin secretion, are depleted of Foxo1 and MafA, and include a Neurogenin3-positive subset. RNA sequencing analysis demonstrates that ALDH+ cells are characterized by: (i) impaired oxidative phosphorylation and mitochondrial complex I, IV, and V; (ii) activated RICTOR; and (iii) progenitor cell markers. We propose that impaired mitochondrial function marks the progression from metabolic inflexibility to dedifferentiation in the natural history of beta cell failure. RNA-Sequencing analysis of 2 different cell types in 2 different genotype categories.