Hemangioblasts are known as the common precursors for primitive hematopoietic and endothelial lineages. Their existence has been supported mainly by the observation that both cell types develop in close proximity and by in vitro differentiation and genetic studies. However, more compelling evidence will arise from tracking their cell fates using a lineage-specific marker. We report the identification of a hemangioblast-specific enhancer (Hb) located in the cis-regulatory region of chick Cerberus gene (cCer) that is able to direct the expression of enhanced green fluorescent protein (eGFP) to the precursors of yolk sac blood and endothelial cells in electroporated chick embryos. Moreover, we present the Hb-eGFP reporter as a powerful live imaging tool for visualizing hemangioblast cell fate and blood island morphogenesis. We hereby introduce the Hb enhancer as a valuable resource for genetically targeting the hemangioblast population as well as for studying the dynamics of vascular and blood cell development.
Targeting the hemangioblast with a novel cell type-specific enhancer.
Specimen part
View SamplesPurpose: The goals of this study are to compare the effects of 5% and 20% oxygen culture on human embryonic stem cells, inlcuding the impact on their transcriptomes. Overall design: mRNA profiles of two human embryonic stem cell lines (MEL1 and MEL2) cultured long term at 5% and 20% oxygen.
Oxygen Regulates Human Pluripotent Stem Cell Metabolic Flux.
Cell line, Subject
View SamplesTranscription is a multi-stage process that coordinates several steps within the transcription cycle including chromatin reorganization, RNA polymerase II recruitment, initiation, promoter clearance and elongation. Recent advances have identified the super elongation complex (SEC), containing the eleven nineteen lysine rich leukemia protein (ELL), as a key regulator of transcriptional elongation. We show here that ELL plays a diverse and kinetically distinct role prior to its assembly into the SEC by stabilizing Pol II recruitment/initiation and entry into the pause site. Loss of ELL destabilizes the PIC complexes and results in disruption of early elongation and promoter proximal chromatin structure prior to recruitment of AFF4 and other SEC components. These changes result in significantly reduced transcriptional activation of rapidly induced genes. Thus, ELL plays an early and essential role during rapid high amplitude gene expression that is required for both Pol II pause site entry and release.
ELL facilitates RNA polymerase II pause site entry and release.
Specimen part, Cell line
View SamplesA number of inhibitors of chemokine CCL2 and its receptor CCR2 are in development and may find application for treating a range of inflammatory conditions, including autoimmune and viral arthritides. Herein we sought to determine the effect of CCR2 deficiency on arthritis caused by an arthritogenic alphavirus, Chikungunya virus.
CCR2 deficiency promotes exacerbated chronic erosive neutrophil-dominated chikungunya virus arthritis.
Sex, Specimen part
View SamplesAlthough it is increasingly accepted that some paternal environmental conditions can influence phenotypes in future generations, it generally remains unclear whether the phenotypes induced in offspring represent specific responses to particular aspects of the paternal exposure history, or whether they represent a more generic response to paternal “quality of life”. To establish a paternal effect model based on a known ligand-receptor interaction and thereby enable pharmacological interrogation of the specificity of the offspring response, we explored the effects of paternal nicotine administration on offspring phenotype in mouse. We show that chronic paternal exposure to nicotine prior to reproduction induced a broad protective response to multiple xenobiotics in the next generation. This effect manifested as increased survival following an injection of toxic levels of either nicotine or of cocaine, was specific to male offspring, and was only observed after offspring were first acclimated to sublethal doses of nicotine or cocaine. Mechanistically, the reprogrammed state was characterized by enhanced clearance of nicotine in drug-acclimated animals, accompanied by hepatic upregulation of genes involved in xenobiotic metabolism. Surprisingly, this protective effect could also be induced by paternal exposure to a nicotinic receptor antagonist as well as to nicotine, suggesting that paternal xenobiotic exposure, rather than nicotinic receptor signaling, is likely to be responsible for programming of offspring drug resistance. Taken together, our data show that paternal drug exposure can induce a protective phenotype in offspring by enhancing metabolic tolerance to xenobiotics in the environment. Overall design: Hepatocytes were isolated from 8 week-old male F1 animals from control (TA) and nicotine-exposed (NIC) fathers, and allowed to adhere to the bottom of the well for three hours. Nonadherent cells were then removed, and fresh culture medium was then added. Cells were harvested at different time points in Trizol, and total RNA was extracted. Strand specific libraries were prepared from all samples, and sequenced on Illumina NextSeq500.
Paternal nicotine exposure alters hepatic xenobiotic metabolism in offspring.
Sex, Specimen part, Cell line, Subject
View SamplesThe application of human embryonic stem (ES) cells has an inherent reliance on understanding the starting cell population. Human ES cells differ from mouse ES cells and the specific embryonic origin of both cell types is unclear. Previous work suggested that mouse ES cells could only be obtained from the embryo prior to implantation in the uterus. Here we show that cell lines can be derived from the epiblast, a tissue of the post-implantation embryo that generates the embryo proper. These cells, which we refer to as EpiSCs (post-implantation epiblast-derived stem cells), express transcription factors known to regulate pluripotency, maintain their genomic integrity, and robustly differentiate into the major somatic cell types as well as primordial germ cells (PGCs). The post-ES cell lines are distinct from mouse ES cells in their epigenetic state and the signals controlling their differentiation. Furthermore, post-ES and human ES cells share patterns of gene expression and signalling responses that normally function in the epiblast. These results show that epiblast cells can be maintained as stable cell lines and interrogated to understand how pluripotent cells generate distinct fates during early development.
New cell lines from mouse epiblast share defining features with human embryonic stem cells.
No sample metadata fields
View SamplesThe application of human embryonic stem (ES) cells in medicine
New cell lines from mouse epiblast share defining features with human embryonic stem cells.
No sample metadata fields
View SamplesA delay in the mammalian inflammatory response is a prominent feature of infection with Yersinia pestis, the agent of bubonic and pneumonic plague. Y. pestis factors have been identified that either do not stimulate a normal inflammatory response, or actively suppress it. Prominent among these are components of the Type III secretion system that is encoded on the Yersinia virulence plasmid (pYV). We used a rat model of bubonic plague to characterize the kinetics and extent of the mammalian transcriptomic response to infection with wild-type or pYV-negative Y. pestis in the draining lymph node. Remarkably, dissemination and multiplication of wild-type Y. pestis during the bubonic stage of disease did not induce any detectable gene expression response by host lymph node cells. This was followed, however, by an extensive transcriptomic response, including upregulation of several cytokine, chemokine, and other immune response genes, after systemic spread during septicemic plague. Matched lymph node samples used for histopathology and extracellular cytokine measurements, combined with the microarray data set, broadly outlined the mammalian immune response to Y. pestis and how it is influenced by pYV-encoded factors. The results indicate that both WT and pYV Y. pestis induce primarily a Th17 response, and not a Th1 or Th2 response. In the absence of pYV, a sustained recruitment of polymorphonuclear leukocytes, the major Th17 effector cell, to the lymph node resulted in clearance of infection. Thus, the ability to counteract a Th17- driven PMN response in the lymph node appears to be a major function of the Y. pestis virulence plasmid. In contrast, classic markers of the proinflammatory response and macrophage activation, such as TNF- and IFN-, were not induced at all by pYV Y. pestis, and appeared only late in infection with WT Y. pestis.
Transcriptomic and innate immune responses to Yersinia pestis in the lymph node during bubonic plague.
Sex, Specimen part, Treatment, Time
View SamplesNonsense-mediated RNA decay (NMD) is regulated by a variety of cellular stresses. We expose U2OS cells to several stresses and assess RNA expression in the absence of transcription (i.e. stability). These studies identify transcripts that are stabilized by the physiological inhibition of NMD.
Inhibition of nonsense-mediated RNA decay by the tumor microenvironment promotes tumorigenesis.
Specimen part, Cell line, Treatment, Time
View SamplesComparison of mouse ES cells and three different XEN cell cultures.
Imprinted X-inactivation in extra-embryonic endoderm cell lines from mouse blastocysts.
No sample metadata fields
View Samples