Although a large set of data is available concerning organogenesis in animal models, information remains scarce on human organogenesis. In this work, we performed temporal mapping of human fetal pancreatic organogenesis using cell surface markers. We demonstrate that in the human fetal pancreas at 7 weeks of development, the glycoprotein 2 (GP2) marks a multipotent cell population that will differentiate either into the acinar, ductal and endocrine lineages. Development towards the acinar lineage is paralleled by a substantial increase in GP2 expression. Conversely, a subset of the multipotent GP2+ population undergoes endocrine differentiation by down-regulating GP2 and CD142 and turning on NEUROG3, an early marker of endocrine differentiation. Endocrine maturation will progress by up-regulating SUSD2 and lowering ECAD levels. Finally, we show that in vitro differentiation of pancreatic endocrine cells derived from human pluripotent stem cells mimics key in vivo events. Our work constitutes a powerful approach to more precisely define intermediate cell population during conversion of multipotent progenitors into the 3 main human pancreatic cell types (acinar, ductal and endocrine) in vivo. As such, the data pave the way to extend our understanding of the origin of mature human pancreatic cell types and how such lineage decisions are regulated.
Reconstructing human pancreatic differentiation by mapping specific cell populations during development.
Specimen part
View SamplesAccess to an unlimited number of human pancreatic beta cells represents a major challenge in the field of diabetes to better dissect human beta cell functions and to make significant progress in drug discovery and cell replacement therapies. We previously reported the generation of the EndoC-bH1 human beta cell line that was generated by targeted oncogenesis in human fetal pancreases followed by in vivo cell differentiation in mice. Such cell line displayed many functional properties of adult beta cells. Here we devised a novel strategy to generate conditionally immortalized human beta cell lines based on CRE-mediated excision of immortalizing transgenes. The resulting EndoC-bH2 cell line can be massively amplified in vitro. Transgenes are next efficiently excised upon CRE expression leading to cell proliferation arrest and strong enhancement of beta cell specific features such as insulin expression, content and secretion. Excised EndoC-bH2 cells are close to authentic human beta cells and represent a unique tool to further study beta cell function and to understand why adult human beta cells are refractory to proliferation and how to achieve drug-dependent mobilization towards beta cell expansion.
Development of a conditionally immortalized human pancreatic β cell line.
Specimen part
View SamplesWe report RNA Seq analysis using Illumina nextSeq500 of human beta cells EndoC-BH1 treated with FGF2 to induce dedifferentiation. FGF2 treatment induced dedifferentiation of EndoC-BH1 cells. Indeed, we observed a strong decrease in expression of ß-cell markers, (INS, MAFB, SLC2A2, SLC30A8 and GCK). Opposingly, we identifed positive markers of human ß cell dedifferentiation, as attested by increased expression of mature ß-cell disallowed transcription factors (MYC, HES1, SOX9 and NEUROG3). Interestingly, our temporal analysis revealed that loss of expression of ß cell specific markers preceded the induction of ß cell disallowed genes. Overall design: human beta cells EndoC-BH1 were treated with FGF2 (100ng/L) during 4, 24, 72 and 144h. RNA was isolated post treatment, along with the non-treated controls, and RNA Seq was performed using Illumina nextSeq500 to generate a full transcriptome analysis of gene expression during dedifferentiation of pancreatic beta cells.
Modeling human pancreatic beta cell dedifferentiation.
Specimen part, Cell line, Subject, Time
View SamplesSTN7-dependent phosphorylation of an as yet unknown thylakoid protein triggers the signaling events associated with the long-term acclimatory response (LTR). The LTR-associated signaling events regulate the expression of photosynthesis-related genes on the post-transcriptional level (nucleus), as indicated by transcript profiling in LTR mutants.
Arabidopsis STN7 kinase provides a link between short- and long-term photosynthetic acclimation.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Differential roles for MBD2 and MBD3 at methylated CpG islands, active promoters and binding to exon sequences.
Specimen part, Cell line
View SamplesThe heterogeneous collection of NuRD complexes can be grouped into the MBD2 or MBD3 containing complexes MBD2-NuRD and MBD3-NuRD. MBD2 is known to bind to methylated CpG sequences in vitro in contrast to MBD3. Although functional differences have been described, a direct comparison of MBD2 and MBD3 in respect to genome-wide binding and function has been lacking. Here we show when depleting cells for MBD2, the MBD2 bound genes increase their activity, whereas MBD2 plus MBD3 bound genes reduce their activity. Most strikingly, MBD3 is enriched at active promoters, whereas MBD2 is bound at methylated promoters and enriched at exon sequences of active genes. This suggests a functional connection between MBD2 binding to chromatin and splicing.
Differential roles for MBD2 and MBD3 at methylated CpG islands, active promoters and binding to exon sequences.
Cell line
View SamplesWe utilized our transgenic Fgd5-mCherry mouse to sort and RNAseq for HSCs under acute immune activation (with pIC) to reveal a complex cell cycle gene expression and an upregulated IFN I/II signature Overall design: RNAseq of bone marrow Lineage-Sca1+cKit+CD150+mCherry+ cells (1000) 24hrs after pIC was administered and control (PBS treated)
Identification of immune-activated hematopoietic stem cells.
Specimen part, Cell line, Treatment, Subject
View SamplesBipolar disorder (BD) has an estimated heritability of about 80%. Different pathways and candidate genes may contribute to the pathogenesis of BD, but definite mechanisms are yet unresolved. In a previous study, we identified the single nucleotide polymorphism (SNP) rs4500567, located in the upstream region of Tetraspanin 8 (TSPAN8), to be associated with bipolar disorder (BD).
The regulation of tetraspanin 8 gene expression-A potential new mechanism in the pathogenesis of bipolar disorder.
Cell line
View SamplesAcute myeloid leukemia (AML) is characterized by molecular heterogeneity. As commonly altered genomic regions point to candidate genes involved in leukemogenesis, we used microarray-based comparative genomic hybridization and single nucleotide polymorphism profiling data of 391 AML cases to further narrow down genomic regions of interest. Targeted-resequencing of 1000 genes located in the critical regions was performed in a representative cohort of 50 AML samples comprising all major cytogenetic subgroups. We identified 120 missense/nonsense mutations as well as 60 insertions/deletions affecting 73 different genes (~3.6 tumor-specific aberrations/AML). While most of the newly identified alterations were non-recurrent, we observed a number of mutations affecting genes involved in epigenetic regulation including known candidates like TET2, TET1, DNMT3A and DNMT1, as well as mutations in the histone methyltransferases NSD1, EZH2 and MLL3. Furthermore, we found mutations in the splicing factor SFPQ and in the non-classical regulators of mRNA-processing CTCF and RAD21. These splicing-related mutations affected 10% of AML patients in a mutually exclusive manner. In conclusion, we could identify a significant enrichment of alterations in genes involved in aberrant splicing and epigenetic regulation in genomic regions commonly altered in AML, highlighting their important role in the molecular pathogenesis of AML.
Commonly altered genomic regions in acute myeloid leukemia are enriched for somatic mutations involved in chromatin remodeling and splicing.
Specimen part, Disease
View SamplesDefective insulin secretion by pancreatic ß cells underlies the development of type 2 diabetes (T2D). High fat diet-fed mice are commonly used to study diabetes progression, but studies are usually limited to a single strain, such as C57Bl/6J. Here, we use a systems biology approach to integrate large phenotypic and islet transcriptomic data sets from six commonly used strains fed a high fat or regular chow diet to identify genes associated with glucose intolerance and insulin secretion. One of these genes is Elovl2, encoding very long chain fatty acid elongase 2. ELOVL2 is responsible for the synthesis of the polyunsaturated fatty acid, docosahexaenoic acid (DHA). We show that DHA rescues glucose-induced insulin secretion and cytosolic Ca2+ influx impaired by glucolipotoxicity, and that Elovl2 over-expression is able to restore the insulin secretion defect under these conditions. We propose that increased endogenous DHA levels resulting from Elovl2 up-regulation counteracts the insulin secretion defect associated with glucolipotoxicity. Although we focus our experimental validation on Elovl2, the comprehensive data set and integrative network model we used to identify this candidate gene represents an important novel resource to dissect the molecular aetiology of ß cell failure in murine models. Overall design: 6 mouse strains, 4 time points, 2 diets
Molecular phenotyping of multiple mouse strains under metabolic challenge uncovers a role for <i>Elovl2</i> in glucose-induced insulin secretion.
Specimen part, Cell line, Subject, Time
View Samples