We performed whole-genome gene expression profiling in Pik3cg-/- mice and subsequent gene ontology clustering of differentially expressed genes compared to wild type mice, in order to investigate the role of Pik3cg in platelet membrane biogenesis and blood coagulation.
Maps of open chromatin guide the functional follow-up of genome-wide association signals: application to hematological traits.
Sex, Specimen part
View SamplesNotch1 deficient hair matrix keratinocytes have lower mitotic rates, resulting in smaller follicles with fewer cells. In addition, the ratio of melanocytes to keratinocytes is greatly reduced. Microarray was performed to study downstream mechanism of Notch1-deficiency
Bi-compartmental communication contributes to the opposite proliferative behavior of Notch1-deficient hair follicle and epidermal keratinocytes.
No sample metadata fields
View SamplesPro-inflammatory cytokines were shown to promote growth and survival of cancerous cells. TNF induced RelA:p50 NF-B dimer via the canonical pathway is thought to link inflammation with cancer. Integrating biochemical and computational studies we identify that deficiency of non-canonical signal transducer p100 triggers a positive autoregulatory loop, which instead perpetuates an alternate RelB:p50 containing NF-B activity upon TNF treatment. TNF stimulated RelB:p50 dimer is sufficient for mediating NF-B target gene-expressions and suppressing apoptotic cellular death independent of principal NF-B subunit RelA. We further demonstrate that activating mutations in non-canonical NF-B module deplete multiple myeloma cells of p100, thereby, provoking autoregulatory RelB:p50 activation. Finally, autoregulatory control reinforces protracted pro-survival NF-B response, albeit comprising of RelB:p50, upon TNF priming that protects myeloma cells with dysfunctional p100 from subsequent apoptotic insults. In sum, we present evidence for positive autoregulation mediated through the NF-B system and its potential involvement in human neoplasm.
Non-canonical NFκB mutations reinforce pro-survival TNF response in multiple myeloma through an autoregulatory RelB:p50 NFκB pathway.
Specimen part, Treatment
View SamplesLgr5+ adult intestinal stem cells are highly proliferative throughout life. Single Lgr5+ stem cells can be cultured into 3D epithelial organoids containing all cell types at nearnormal ratios. Culture conditions to generate the main cell types have been established previously, but signals inducing the various types of enteroendocrine cells (EECs) have remained elusive. Here we generate quiescent Lgr5+ stem cells in vitro by inhibition of the EGF-receptor (EGFR) and mitogen-associated protein kinase (MAPK) signaling pathways in organoids, a state that can be readily reversed. Quiescent Lgr5+ stem cells gain a distinct molecular signature, biased towards EEC differentiation. Indeed, combined inhibition of Wnt, Notch and MAPK pathways efficiently generates a diversity of EEC subtypes in vitro. Our observations uncouple Wnt-dependent stem cell maintenance from EGF-dependent proliferation and cell fate choice, and provide an in vitro approach for the study of the elusive EECs. Overall design: We established a stable culture of quiescent Lgr5+ intestinal stem cells in culture. These highly resemble quiescent secretory precursors, which has high EEC differentiation potential. Following on this lead, we elucidated what signals are required to generate EEC cells of all varieties, and provide a method to produce these EEC cells in large numbers.
Induced Quiescence of Lgr5+ Stem Cells in Intestinal Organoids Enables Differentiation of Hormone-Producing Enteroendocrine Cells.
Specimen part, Cell line, Subject
View SamplesSox2 is required to maintain osteosarcoma cell tumor initiation.Knockdown of Sox2 leads tpo loss of tumorigenic properties. To examine gene expression changes upon Sox2 knockdown, we performed microarray analysis on mouse osteosarcoma cells expressing scrambled or Sox2shRNA. We found that genes upregulated upon Sox2 knockdown included osteoblast diffrentiation genes and genes down regulated included cell cycle and RNA processing genes as well as YAP-TEAD target genes.
Sox2 antagonizes the Hippo pathway to maintain stemness in cancer cells.
Specimen part, Cell line
View SamplesThe Mediator complex regulates gene transcription by linking basal transcriptional machinery with DNA-bound transcription factors. The activity of the Mediator complex is mainly controlled by a kinase submodule that is comprised of four proteins, including MED12. Although ubiquitously expressed, Mediator subunits can differentially regulate gene expression in a tissue-specific manner. Here, we report that MED12 is required for normal cardiac function such that mice with conditional cardiac-specific deletion of MED12 display progressive dilated cardiomyopathy. Loss of MED12 perturbs expression of calcium handling genes in the heart, consequently altering calcium cycling in cardiomyocytes and disrupting cardiac electrical activity. We identified transcription factors that regulate expression of calcium-handling genes that are downregulated in the heart in the absence of MED12, and found that MED12 localizes to transcription factor consensus sequences within calcium handling genes. We showed that MED12 interacts with one such transcription factor, MEF2, in cardiomyocytes, and that MED12 and MEF2 co-occupy promoters of calcium handling genes. Furthermore, we demonstrated that MED12 enhances MEF2 transcriptional activity and overexpression of both increases expression of calcium handling genes in cardiomyocytes. Our data support a role for MED12 as a coordinator of transcription through MEF2 and other transcription factors. We conclude that MED12 is a regulator of a network of calcium handling genes, consequently “mediating” contractility in the mammalian heart. Overall design: Ventricle mRNA profiles of 1-day old control (CTL, CreNEG) and cardiac-specific Med12 knockout mice (Med12cKO, CrePOS) were generated by deep sequencing, in triplicate, using Illumina.
MED12 regulates a transcriptional network of calcium-handling genes in the heart.
No sample metadata fields
View SamplesUnderstanding the development and function of an organ requires the characterization of all of its cell types. Traditional methods for visualizing and isolating sub-populations of cells are based on mRNA or protein expression of only few known marker genes. The unequivocal identification of a specific marker gene, however, poses a major challenge, particularly if this cell type is rare. Identifying rare cell types, such as stem cells, short-lived progenitors, cancer stem cells, or circulating tumor cells is crucial to acquire a better understanding of normal or diseased tissue biology. To address this challenge we sequenced the transcriptome of hundreds of randomly selected cells from mouse intestinal organoids, cultured self-organizing epithelial structures that contain all cell lineages of the mammalian intestine. Organoid buds, like intestinal crypts, harbor stem cells that continuously differentiate into a variety of cell types, occurring at widely different abundances. Since available computational methods can only resolve more abundant cell types, we developed RaceID, an algorithm for rare cell type identification in complex populations of single cells. We demonstrate that this algorithm can resolve cell types represented by only a single cell in a population of randomly sampled organoid cells. We use this algorithm to identify Reg4 as a novel marker for enteroendocrine cells, a rare population of hormone producing intestinal cells. Next, we use Reg4 expression to enrich for these rare cells and investigate the heterogeneity within this population. Reassuringly, RaceID confirmed the existence of known enteroendocrine lineages, and moreover, discovered novel subtypes, which we subsequently validated in vivo. Having validated RaceID by this proof-of-principle experiment we then apply the algorithm to ex vivo isolated LGR5 positive cells and their direct progeny and demonstrate homogeneity of the stem cell pool. We envision broad applicability of our method for discovering rare cell types and the corresponding marker genes in healthy and diseased organs. Overall design: Small intestinal crypts were isolated from a single wild-type C57BL/6 mouse, a Reg4-dsRed-knock-in mouse and an Lgr5-GFP-DTR mouse. The crypts were propagated and expanded in culture as organoids. For each experiment, multiple organoids were harvested and dissociated into single cells. Each experiment was done twice, using different passage of the same organoid culture. We also included a pool-and-split control for 96 Reg4-dsRed positive intetsinal cells and a control library with 5 mouse embryonic stem cells (wells 1-5), 5 mouse embryonic fibroblasts (wells 6-10), 75 random organoid cells (wells 11-85), 5 wells without primer and without template (wells 86 and 93-96), and five wells with primer and without template (wells 87-92). We also sequenced two 96 well plates of Lgr5-EGFP positive single cells isolated ex vivo, and Lgr5 progeny collected after five days of lineage tracing. Label induction was performed using an Lgr5-Cre reporter mouse expressing YFP from Rosa26 promoter with a loxP flanked transcriptional road block in between. Five 96 well plates of YFP positive were sequenced. Sample number four also contains also unrelated samples (single cell barcode 49-96), which should be discarded.
Single-cell messenger RNA sequencing reveals rare intestinal cell types.
No sample metadata fields
View SamplesMammalian epidermal stem cells maintain homeostasis of skin epidermis and contribute to its regeneration throughout adult life. While two-dimensional mouse epidermal stem cell cultures have been established decades ago, a long-term, feeder cell- and serum-free culture system recapitulating murine epidermal architecture has not been available. Here we describe an epidermal organoid culture system that allows long-term, genetically stable expansion of adult epidermal stem cells. Our epidermal expansion media combines atypically high calcium concentrations, activation of cyclic AMP, FGF and R-spondin signaling with inhibition of BMP signaling. Organoids are established robustly from adult mouse skin and expand over at least 6 months, while maintaining the basal-apical organization of the mouse interfollicular epidermis. The system represents a powerful tool to study epidermal homeostasis and disease in vitro. Overall design: We establish an organoid culture system for long-term expansion of mouse epidermal stem cells. Using histological methods as well as low-coverage multiplexed RNA sequencing, we show that cultured organoids resembled interfollicular epidermis. We analyzed a total of 23 samples, including 6 controls that are isolated from the skin of mice. None-passaged as well as cultured organoids were compared with replicates. Differences growth factors and small molecules that allow expansion of organoids were compared with replicates.
Long-term expansion and differentiation of adult murine epidermal stem cells in 3D organoid cultures.
Cell line, Subject
View SamplesThe identification of Lgr5 as an intestinal stem cell marker has made it possible to isolate and study primary stem cells from small intestine. Using the cell cycle specific expression og the mKi67 gene, we generated a novel Ki67-RFP knock-in allele which identifies dividing cells. Using Lgr5-GFP;Ki67-RFP mice, we isolated CBCs with distinct Wnt signaling levels and cell cycle features, and analyzed their global gene expression pattern using microarrays. We concluded that the cycling Lgr5hi stem cells exit the cell cycle in transition into the secretory lineage. Lgr5med Ki67low intermediate precursors reside in the zone of differentiation, resemble quiescent stem cells and generate the Dll1+ secretory precursors and the label retaining cells. Our findings support the cycling stem cell hypothesis and highlight the heterogeneity of early progenitors during lineage commitment.
Mapping early fate determination in Lgr5+ crypt stem cells using a novel Ki67-RFP allele.
Specimen part
View SamplesAnaplastic large-cell lymphoma (ALCL) makes up approximately 15% of paediatric non-Hodgkin's lymphomas of childhood. The vast majority of them is associated with the t(2;5)(p23;q35) translocation that results in the expression of a hybrid oncogenic tyrosine kinase, NPM-ALK. In order to investigate ALCL biological characteristics we used transcriptional profiling approach. Genome-wide gene expression profiling, performed on 23 paediatric ALCL and 12 reactive lymph nodes specimens, showed two novel ALCL subgroups based on their NPM-ALK expression levels (named (ALK low and ALK high). Gene set enrichment analysis revealed, in ALK low samples, a positive enrichment of genes involved in the Interleukin signaling pathway, whereas we found increased expression of genes related to cell cycle progression and division in ALK high tumour samples, such as Aurora Kinase A (AURKA) and B (AURKB). Growth inhibition was observed upon administration of AURKA and AURKB inhibitors Alisertib and Barasertib and it was associated with perturbation of the cell cycle and induction of apoptosis. In conclusion we identified two novel ALCL subgroups, which display unique biological characteristics suggesting sensitivity to distinct targeted therapies.
NPM-ALK expression levels identify two distinct subtypes of paediatric anaplastic large cell lymphoma.
No sample metadata fields
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