A prevalent hypothesis for the cell-to-cell coordination of the phenomena of early development is that a defined mixture of different mRNA species at specific abundances in each cell determines fate and behavior. With this dataset we explore this hypothesis by quantifying the abundance of every mRNA species in every individual cell of the early C. elegans embryo, for which the exact life history and fate is precisely documented. Overall design: Embryos of the 1-, 2-, 4-, 8- and 16-cell stage were dissected into complete sets of single cells, and each cell from each set was sequenced individually using SMARTer technology. 5-9 replicates were generated for each stage. Most cell identities were unknown upon sequencing, but were deduced from by their transcriptomes post hoc.
A Transcriptional Lineage of the Early C. elegans Embryo.
Specimen part, Subject
View SamplesGlial progenitor cells comprise the most abundant population of progenitor cells in the adult human brain. They are responsible for CNS remyelination, and likely contribute to the astrogliotic response to brain injury and degeneration as well. Adult human GPCs are biased to differentiate as oligodendrocytes and elaborate new myelin, and yet they retain multilineage plasticity, and can give rise to neurons as well as astrocytes and oligodendrocytes once removed from the adult parenchymal environment. GPCs retain strong mechanisms for cell-autonomous self-renewal, and yet both their phenotype and fate may be dictated by their microenvironment. Using the transcriptional profiles of acutely isolated GPCs, we have begun to understand the operative ligand-receptor interactions involved in these processes, and have identified several key signaling pathways by which adult human GPCs may be reliably instructed to either oligodendrocytic or astrocytic fate. In addition, we have noted significant differences between the expressed genes and dominant signaling pathways of fetal and adult human GPCs, as well as between rodent and human GPCs. The latter data in particular call into question therapeutic strategies predicated solely upon data obtained using rodents, while perhaps highlighting the extent to which evolution has been attended by the phylogenetic modification of glial phenotype and function.
Fate determination of adult human glial progenitor cells.
Specimen part, Subject
View SamplesMuscle denervation due to injury, disease or aging results in impaired motor function. Restoring neuromuscular communication requires axonal regrowth and regeneration of neuromuscular synapses. Muscle activity inhibits neuromuscular synapse regeneration. The mechanism by which muscle activity regulates regeneration of synapses is poorly understood. Dach2 and Hdac9 are activity-regulated transcriptional co-repressors that are highly expressed in innervated muscle and suppressed following muscle denervation. Here, we report that Dach2 and Hdac9 inhibit regeneration of neuromuscular synapses. Importantly, we identified Myog and Gdf5 as muscle-specific Dach2/Hdac9-regulated genes that stimulate neuromuscular regeneration in denervated muscle. Interestingly, Gdf5 also stimulates presynaptic differentiation and inhibits branching of regenerating neurons. Finally, we found that Dach2 and Hdac9 suppress miR206 expression, a microRNA involved in enhancing neuromuscular regeneration. Overall design: RNAseq on innervated and 3 day denervated adult soleus muscle from wildtype mice is compared with that from 3 day denervated soleus muscle from Dach2/Hdac9 deleted mice to identify Dach2/Hdac9-regulated genes.
Dach2-Hdac9 signaling regulates reinnervation of muscle endplates.
No sample metadata fields
View SamplesGlial progenitor cells (GPCs) pervade the human brain. These cells express gangliosides recognized by MAb A2B5, and some but not all can generate oligodendrocytes. Since some A2B5+ GPCs express PDGFa receptor (PDGFRa), which is critical to oligodendrocyte development, we asked if PDGFRa-directed sorting might isolate oligodendrocyte-competent progenitors. We used FACS to sort PDGFRa+ cells from the second trimester fetal human forebrain, based on expression of the PDGFRa epitope CD140a. CD140a+ cells could be maintained as mitotic progenitors that could be instructed to either oligodendrocyte or astrocyte phenotype. Transplanted CD140a+ cells robustly myelinated the hypomyelinated shiverer mouse brain. Microarray confirmed that CD140a+ cells differentially expressed PDGFRA, NG2, OLIG1/2, NKX2.2 and SOX2. Some expressed CD9, thereby defining a CD140a+/CD9+ fraction of oligodendrocyte-biased progenitors. CD140a+ cells differentially expressed genes of the PTN-PTPRZ1, wnt, notch and BMP pathways, suggesting the interaction of self-renewal and fate-restricting pathways in these cells, while identifying targets for their mobilization and instruction.
CD140a identifies a population of highly myelinogenic, migration-competent and efficiently engrafting human oligodendrocyte progenitor cells.
Specimen part
View SamplesGene expression heterogeneity in the pluripotent state of mouse embryonic stem cells (mESCs) has been increasingly well-characterized. In contrast, exit from pluripotency and lineage commitment have not been studied systematically at the single-cell level. Here we measured the gene expression dynamics of retinoic acid driven mESC differentiation using an unbiased single-cell transcriptomics approach. We found that the exit from pluripotency marks the start of a lineage bifurcation as well as a transient phase of susceptibility to lineage specifying signals. Our study revealed several transcriptional signatures of this phase, including a sharp increase of gene expression variability and a handover between two classes of transcription factors. In summary, we provide a comprehensive analysis of lineage commitment at the single cell level, a potential stepping stone to improved lineage control through timing of differentiation cues. Overall design: Bulk and single-cell RNA-seq (SCRB-seq and SMART-seq) of mouse embryonic stem cells after different periods of continuous exposure to retinoic acid. Bulk RNA-seq of cell lines derived after retinoic exposure and after differentiation with retinoic acid and MEK inhibitor combined.
Dynamics of lineage commitment revealed by single-cell transcriptomics of differentiating embryonic stem cells.
Cell line, Subject
View SamplesIn order to obtain a global picture regarding regulation of p53 in liver cells we used HepG2 hepatoma cells.We created two isogenic sub-cultures of HepG2 cells with altered expression of p53.
Chemotherapeutic agents induce the expression and activity of their clearing enzyme CYP3A4 by activating p53.
Specimen part, Cell line
View SamplesDuring pneumonic plague, the bacterium Yersinia pestis elicits the development of inflammatory lung lesions that continue to expand throughout infection. This lesion development and persistence is poorly understood. Here, we examine spatially distinct regions of lung lesions using laser capture microdissection and RNAseq analysis to identify transcriptional differences between lesion microenvironments. We show that cellular pathways involved in leukocyte migration and apoptosis are down regulated in the center of lung lesions compared to the periphery. Probing for the bacterial factor(s) important for the alteration in neutrophil survival, we show both in vitro and in vivo that Y. pestis increases neutrophil survival in a manner that is dependent on the type-III secretion system effector YopM. This research explores the complexity of spatially distinct host - microbe interactions and emphasizes the importance of cell relevance in assays in order to fully understand Y. pestis virulence. Overall design: We examine spatially distinct regions of lung lesions using laser capture microdissection and RNAseq analysis to identify transcriptional differences between lesion microenvironments. Sample types: uninfected BM-PMN, infected BM-PMN, lesion periphery, lesion center.
Spatially distinct neutrophil responses within the inflammatory lesions of pneumonic plague.
No sample metadata fields
View SamplesThe complex response of murine macrophages to infection with Streptococcus pyogenes was investigated at the level of gene expression using a high-density oligomer microarray. More than 400 genes were identified as being differentially regulated. Many of the up-regulated genes encoded molecules were involved in immune response and inflammation, transcription, signalling, apoptosis, cell cycle, electron transport and cell adhesion. Of particular interest was the up-regulation of proinflammatory cytokines, typical of the classically activated macrophages (M1 phenotype) such as TNF-?, IL-1 and IL-6, and also the up-regulation of anti-inflammatory mediators such as IL-1ra and IL-10 associated with macrophage alternative activation (M2 phenotype). Furthermore, the gene encoding inducible nitric oxide synthase (iNOS), an enzyme typically implicated in classical activation was not induced in infected macrophages. Instead, the gene encoding arginase, a competitor for the iNOS substrate arginine and involved in the alternative activation pathway was up-regulated in S. pyogenes-infected cells. Thus, the microarray-based gene expression analysis demonstrated that S. pyogenes induced an atypical activation program in macrophages with some but not all features of classically or alternatively activation phenotypes. The microarray data also suggested that the bactericidal activity of macrophages against S. pyogenes is mediated by phagocyte oxydase since p47phox was up-regulated in infected cells. Indeed, the in vivo and in vitro killing of S. pyogenes was markedly diminished in the absence of functional phagocyte (p47phox-/-) but not in the absence of iNOS (iNOS-/-). Understanding how macrophages respond to S. pyogenes at the molecular level may facilitate the development of new therapeutic paradigms.
Transcriptome analysis of murine macrophages in response to infection with Streptococcus pyogenes reveals an unusual activation program.
Specimen part
View SamplesSkeletal muscle possesses a remarkable capacity to regenerate when injured, but when confronted with major traumatic injury resulting in volumetric muscle loss (VML), the regenerative process consistently fails. The loss of muscle tissue and function from VML injury has prompted development of a suite of therapeutic approaches but these strategies have proceeded without a comprehensive understanding of the molecular landscape that drives the injury response. Herein, we administered a VML injury in an established rodent model and monitored the evolution of the healing phenomenology over multiple time points using muscle function testing, histology, and expression profiling by RNA sequencing. The injury response was then compared to a regenerative medicine treatment using orthotopic transplantation of autologous minced muscle grafts (~1?mm3 tissue fragments). A chronic inflammatory and fibrotic response was observed at all time points following VML. These results suggest that the pathological response to VML injury during the acute stage of the healing response overwhelms endogenous and therapeutic regenerative processes. Overall, the data presented delineate key molecular characteristics of the pathobiological response to VML injury that are critical effectors of effective regenerative treatment paradigms. Overall design: RNA-Seq time couse of muscle volumetric muscle loss injury healing with controls
Multiscale analysis of a regenerative therapy for treatment of volumetric muscle loss injury.
No sample metadata fields
View SamplesThe clonal CD3- CD4+ Th2 cell population characterizing some hypereosinophilic syndrome patients stably endures for years provoking a chronic inflammatory skin disease, with a subgroup of patients ultimately progressing to T-cell lymphoma. The aim of this study is the identification of the molecular changes (1) associated with the persistence of the pre-malignant clone (2) associated with the activation of co-stimulatory receptors and (3) associated with the emergence of malignant T-cell subclones.
Molecular profiling of CD3-CD4+ T cells from patients with the lymphocytic variant of hypereosinophilic syndrome reveals targeting of growth control pathways.
Specimen part, Disease, Disease stage, Time
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