A fundamental question in developmental biology is whether there are mechanisms to detect stem cells with mutations that, although not adversely affecting viability, would compromise their ability to contribute to further development. Here, we show that cell competition is a mechanism regulating the fitness of embryonic stem cells (ESCs). We find that ESCs displaying defective bone morphogenetic protein signaling or defective autophagy or that are tetraploid are eliminated at the onset of differentiation by wild-type cells. This elimination occurs in an apoptosis-dependent manner and is mediated by secreted factors. Furthermore, during this process, we find that establishment of differential c-Myc levels is critical and that c-Myc overexpression is sufficient to induce competitive behavior in ESCs. Cell competition is, therefore, a process that allows recognition and elimination of defective cells during the early stages of development and is likely to play important roles in tissue homeostasis and stem cell maintenance.
Competitive interactions eliminate unfit embryonic stem cells at the onset of differentiation.
Specimen part
View SamplesA fundamental question in developmental biology is whether there are mechanisms to detect stem cells with mutations that although do not adversely affect their viability, would compromise their ability to contribute to further development. Here we show that cell competition is a novel mechanism regulating the fitness of embryonic stem cells (ESCs). We find that ESCs displaying defective BMP signalling, defective autophagy or are tetraploid are eliminated at the onset of differentiation by wild-type cells. This elimination occurs in an apoptotic dependent manner and is mediated by secreted factors. Furthermore, during this process we find that establishment of differential cMyc levels is critical and that cMyc over-expression is sufficient to induce competitive behaviour in ESCs. Cell competition is therefore a process that allows recognition and elimination of defective cells during the early stages of development and is likely to play important roles in tissue homeostasis and stem cell maintenance.
Competitive interactions eliminate unfit embryonic stem cells at the onset of differentiation.
Specimen part
View SamplesQuantitative Analysis of cortical transcriptomes through Next Generation Sequencing (RNA-Seq) from wild-type mice, wild-type mice treated with IL1b (200 ng/mouse, 14h), IL-1R8-/- mice and IL-1R8-/- mice treated with IL1b antagonist Anakinra (25 mg/kg per day for 3 consecutive days, i.p. administration). mRNA profiles of cortical tissue from adult wild-type mice, wild-type mice treated with IL1b (200 ng/kg, 14h), IL-1R8-/- mice (Garlanda et al., 2004), and IL-1R8-/- mice treated with Anakinra (25 mg/kg per day for 3 consecutive days, i.p. administration) were generated by next-generation sequencing (RNA-seq) using Illumina HiSeq 2500 apparatus in paired-end configuration (2x125bp). Each condition was assessed in triplicate (12 mRNA-seq libraries) and, to reduce biological variability, each mRNA library was generated from pooled total RNA isolated from cortical tissue of 3 individual mice. In total, 9 mice per condition were used. Libraries were stranded and multiplexed. To increase sequencing depth, libraries were sequenced in two different lanes. All the libraries were loaded in each of the two lanes. Quality control of the raw data was performed with FastQC (http://www.bioinformatics.babraham.ac.uk/projects/fastqc/). Libraries were trimmed for adapter removal using Trimmomatic (Bolger et al., 2014) and mapped to reference genome (Ensembl GRCm38) using TopHat2 (Kim et al., 2013) and Bowtie2 (Langmead et al., 2009). Library sizes of primary mapped reads were between 70 and 96 million reads. Samtools was used to manipulate BAM files (Li et al., 2009). For calling of differentially expressed genes (DEG), mapped reads were counted with HTSeq v0.6.1 (Anders et al., 2014) and count tables were analysed using DeSeq2 v1.10.1 R-package (Love et al., 2014) with a design of one factor with four levels (“wild-type”, “wild-type + IL1?”, “IL-1R8-/-”, “IL-1R8-/- + Anakinra"), and differences between groups were tested using contrasts for wild-type + IL1b versus wild-type; IL-1R8-/- versus wild-type; IL-1R8-/- + Kineret versus wild-type. For consideration of differentially regulated genes between conditions, we used adjusted p-value < 0.1 or adjusted p-value < 0.05 as indicated in the manuscript. Overall design: mRNA profiles in adult mouse cerebral cortex of wild type (WT), WT mice treated with IL1b (200 ng/kg, 14h), IL-1R8-/- mice, and IL-1R8-/- mice treated with IL1b antagonist Anakinra (25 mg/kg per day for 3 consecutive days, i.p. administration) were generated by deep sequencing, in triplicate, using Illumina HiSeq 2500. Each sample was prepared by pooling cortical tissue from 3 idenpendent mice.
Lack of IL-1R8 in neurons causes hyperactivation of IL-1 receptor pathway and induces MECP2-dependent synaptic defects.
Treatment, Subject
View SamplesPancreatic islet endocrine cell and endothelial cell (EC) interactions mediated by vascular endothelial growth factor-A (VEGF-A) signaling are important for islet endocrine cell differentiation and the formation of highly vascularized islets. To dissect how VEGF-A signaling modulates intra-islet vasculature and innervation, islet microenvironment, and ß cell mass, we transiently increased VEGF-A production by ß cells. VEGF-A induction dramatically increased the number of intra-islet ECs but led to ß cell loss. After withdrawal of the VEGF-A stimulus, ß cell mass, function, and islet structure normalized as a result of a robust, but transient, burst in proliferation of pre-existing ß cells. Bone marrow-derived macrophages (MFs) recruited to the site of ß cell injury were crucial for the ß cell proliferation, which was independent of pancreatic location and circulating factors such as glucose. Identification of the signals responsible for the proliferation of adult, terminally differentiated ß cells will improve strategies aimed at ß cell regeneration and expansion. Overall design: Examination of RNA profiles from isolated whole islets from RIP-rtTA; TetO-VEGF-A mice with no doxycycline (Dox) treatment (3 samples) and after 1 week of Dox (3 sample); and islet-derived macrophages (3 samples) and endothelial cells (3 samples) isolated from dispersed purified islets from RIP-rtTA; TetO-VEGF-A mice after 1 week Dox treatment by fluorescence-activated cell sorting using antibodies against CD11b and CD31, respectively.
Vascular endothelial growth factor coordinates islet innervation via vascular scaffolding.
Specimen part, Cell line, Treatment, Subject
View SamplesTuberous Sclerosis Complex (TSC) is a disease caused by autosomal dominant mutations in the TSC1 or TSC2 genes, and is characterized by tumor susceptibility, brain lesions, seizures and behavioral impairments. The TSC1 and TSC2 genes encode proteins forming a complex (TSC), which is a major regulator and suppressor of mammalian target of rapamycin (mTOR) in complex 1 (mTORC1), a signaling complex that promotes cell growth and proliferation. TSC1/2 loss of heterozygosity (LOH) and the subsequent complete loss of TSC regulatory activity in null cells causes mTORC1 dysregulation and TSC-associated brain lesions or other tissue tumors. However, it is not clear whether TSC1/2 heterozygous brain cells are abnormal and contribute to TSC neuropathology. To investigate this issue, we generated induced pluripotent stem cells (iPSCs) from TSC patients and unaffected controls, and utilized these to obtain neural progenitor cells (NPCs) and differentiated neurons in vitro. These patient-derived TSC2 heterozygous NPCs were delayed in their ability to differentiate into neurons. Patient-derived progenitor cells also exhibited a modest activation of mTORC1 signaling downstream of TSC, and a marked attenuation of upstream PI3K/AKT signaling. We further show that pharmacologic AKT inhibition, but not mTORC1 inhibition, causes a neuronal differentiation delay, mimicking the patient phenotype. Together these data suggest that heterozygous TSC2 mutations disrupt neuronal development, potentially contributing to the disease neuropathology, and that this defect may result from dysregulated AKT signaling in neural progenitor cells. Overall design: Two replicates each of TSC#1 and CON#1 NPC cell RNA were prepared for sequencing library preparation and seqeuencing.
Neural progenitors derived from Tuberous Sclerosis Complex patients exhibit attenuated PI3K/AKT signaling and delayed neuronal differentiation.
Specimen part, Subject
View SamplesExtremely variable clinic and genetic features characterize Mitochondrial Encephalomyopathy Disorders (MED). Pathogenic mitochondrial DNA (mtDNA) defects can be divided into large-scale rearrangements and single point mutations. Clinical manifestations become evident when a threshold percentage of the total mtDNA is mutated. In some MED, the "mutant load" in an affected tissue is directly related to the severity of the phenotype. However, the clinical phenotype is not simply a direct consequence of the relative abundance of mutated mtDNA. Other factors, such as nuclear background, can contribute to the disease process, resulting in a wide range of phenotypes caused by the same mutation. Using Affymetrix oligonucleotide cDNA microarrays (HG-U133A), we studied the gene expression profile of muscle tissue biopsies obtained from 12 MED patients (4 common 4977-bp deleted mtDNA and 8 A3243G: 4 PEO and 4 MELAS phenotypes) compared with age-matched healthy individuals.
Skeletal muscle gene expression profiling in mitochondrial disorders.
No sample metadata fields
View SamplesSeveral recently emerging ChIP-seq (chromatin immunoprecipitation followed by sequencing) based methods perform chemical steps on bead-bound immunoprecipitated chromatin, posing a challenge for generating similarly treated input controls required for bioinformatics and data quality analyses. Here we present a versatile method for producing technique-specific input controls for ChIP-based methods that utilize additional bead-bound processing steps. Application of this method allowed for discovery of a novel CTCF binding motif from ChIP-exo data. Overall design: HeLa cells were transfected with either a scrambled siRNA or one of two CTCF siRNAs (Thermo Fisher Scientific ? Life technologies) using Lipofectamine RNAiMAX (Thermo Fisher Scientific - Life technologies) and incubated for 24 hr.
PAtCh-Cap: input strategy for improving analysis of ChIP-exo data sets and beyond.
Cell line, Subject
View SamplesThe emerging correlation between aberrant DNA methylation patterns leading to transcriptional responses that promote and progress many cancers has prompted an interest in discerning the associated regulatory mechanisms. ZBTB33 (also known as Kaiso) is a specialized transcription factor that selectively recognizes mCpG-containing sites as well as a sequence-specific DNA target (termed the KBS) utilizing three Cys2His2 zinc fingers. Increasing reports link ZBTB33 overexpression and transcriptional activities with metastatic potential and poor prognosis, though the specific cellular consequences appear to be dependent on disease phenotype. There is currently little mechanistic insight into how various cellular phenotypes are then able to harness the transcriptional capabilities of ZBTB33 to differentially promote and progress the disease state. Here we have mechanistically interrogated the cell cycle responses mediated by the transcriptional activities of ZBTB33 in two different cell lines. Utilizing a series of ZBTB33 depletion and overexpression studies, we have determined that in HeLa cells ZBTB33 directly occupies the promoter regions of cyclin D1 and cyclin E1 in a KBS and methyl-specific manner, respectively, inducing increased proliferation by promoting RB1 hyper-phosphorylation, allowing for E2F transcriptional activity that coordinates an accelerated G1- to S-phase transition. Conversely, in HEK293 cells ZBTB33 indirectly regulates Cyclin E abundance resulting in reduced RB1 phosphorylation, decreased E2F activity and a decelerated transition through G1-phase. Thus, we have identified a novel mechanism by which ZBTB33 directly mediates the highly coordinated cyclin D1/cyclin E1/RB1/E2F signaling pathway controlling the passage through the G1-phase restriction point and accelerating cellular proliferation in a cancer cell line. Overall design: Determination of cellular and transcriptional consequences for ZBTB33 depletion in HeLa cells.
Cell-specific Kaiso (ZBTB33) Regulation of Cell Cycle through Cyclin D1 and Cyclin E1.
Cell line, Subject
View SamplesMycobacteria infect macrophages that aggregate with additional macrophages and lymphocytes to form granulomas. We have used a functional genomics approach to identify immune response genes expressed during granuloma formation in Mycobacterium marinum-infected transparent zebrafish larvae where individual infection steps can be viewed in real time. We assessed RNA expression profiles from zebrafish larvae that were either infected with Mycobacterium marinum, mock-infected, or uninfected. Zebrafish infections were performed at 1 day post-fertilization (dpf), and samples were derived from pools of 6dpf zebrafish larvae.
Tuberculous granuloma induction via interaction of a bacterial secreted protein with host epithelium.
No sample metadata fields
View SamplesWe report the global gene expression of mouse pancreatic cells in a pancreas-specific conditional knock-out mouse for Gata6, as compared with age-matched controls. Total RNA was extracted from the pancreas of 6-8 -week old mice of the two genotypes and analyzed. at this age, Gata6P-/- pancreata are histologically normal, but the acinar differentiation programme is already altered. we observe that loss of Gata6 causes the de-repression of ectopic non-pancreatic genes, as well as some genes involved in the mesenchymal programme. Overall design: mRNA extracted from the pancreas of 4 controls and 4 Gata6P-/- mice was sequenced.
The acinar regulator Gata6 suppresses KrasG12V-driven pancreatic tumorigenesis in mice.
Specimen part, Cell line, Subject
View Samples