Purpose: In all vertebrates, the thymus is necessary and sufficient for production of classic adaptive T cells. The key components of the thymus are cortical and medullary thymic epithelial cells (cTECs and mTECs). Despite the capital role of TECs, our understanding of TEC biology is quite rudimentary. For instance, we ignore what might be the extent of divergence in the functional program of these two TECs populations. It also remains unclear why the number of TECs decreases rapidly with age, thereby leading to progressive thymic insufficiency. Methods: Systems level understanding of cell function begins with gene expression profiling, and the transcriptome is currently the only ''-ome'' that can be reliably tackled in its entirety in freshly harvested primary cells. In order to gain novel insights into TEC biology, we therefore decided to analyse the whole transcriptome of cTECs, mTECs and skin epithelial cells. We elected to analyse gene expression using RNA-seq rather microarrays because RNA-seq has higher sensitivity and dynamic range coupled to lower technical variations. Results: Our deep sequencing approach provides a unique perspective into the transcriptome of TECs. Consistent with their ability to express ectopic genes, we found that mTECs expressed more genes than other cell populations. Out of a total of 15,069 genes expressed in TECs, 25% were differentially expressed by at least 5-fold in cTECs vs. mTECs. Genes expressed at higher levels in cTECs than mTECs regulate numerous cell functions including cell differentiation, cell movement and microtubule dynamics. Almost all positive regulators of the cell cycle were overexpressed in skin ECs relative to TECs. Conclusions: Our RNA-seq data provide novel insights into the transcriptional landscape of TECs, highlight substantial divergences in the transcriptome of TEC subsets and suggest that cell cycle progression is differentially regulated in TECS and skinECs. We believe that our work will therefore represent a valuable resource and will be of great interest to readers working in biological sciences, particularly in the areas of immunology and systems biology. Overall design: The mRNA profiles of cTEC, mTEC (from 14 thymi of 7-days old C57BL/6 mice) and skinEC (from the trunk and dorsum of seven newborn mice) were generated by RNA-sequencing using Illumina HiSeq2000.
Transcriptome sequencing of neonatal thymic epithelial cells.
Specimen part, Cell line, Subject
View SamplesImmune responses in hemophilia A patients to replacement factor VIII can be either tolerogenic or immunogenic, the latter resulting in induction of non-neutralizing anti-factor VIII antibodies or neutralizing antibodies called inhibitors. Since these inhibitors render replacement FVIII treatment essentially ineffective, preventing or eliminating them are of top priority in disease management. The extended half-life recombinant factor VIII Fc fusion protein (rFVIIIFc) is an approved therapy for hemophilia A patients. In addition, it has been reported that rFVIIIFc can induce tolerance to FVIII in hemophilia A patients that have developed inhibitors. Given that the IgG1 Fc region has the potential to interact with immune cells expressing Fc receptors and thereby affect the immune response to rFVIII, we investigated how human macrophages, expressing both Fc receptors and receptors reported to bind FVIII, respond to rFVIIIFc. We show herein that rFVIIIFc, but not rFVIII, uniquely skews macrophages towards an alternatively activated regulatory phenotype. rFVIIIFc initiates signaling events that result in morphological changes, as well as a specific gene expression and metabolic profile that is characteristic of the regulatory type Mox/M2-like macrophages. Further, these changes are dependent on rFVIIIFc-Fc receptor interactions. Our findings elucidate mechanisms of potential immunomodulatory properties of rFVIIIFc. Overall design: Human monocyte-derived macrophages (n=3) were treated with hIgG1, rFVIII or rFVIIIFc for 6h
Recombinant factor VIII Fc fusion protein drives regulatory macrophage polarization.
Specimen part, Treatment, Subject
View SamplesThis study aims at isolate a subpopulation of thymic epithelial cells (TECs) enrich in thymic epithelial progenitors. While recent studies have shown that bipotent TEC progenitors exist in adults, the identity of thymic epithelial progenitors (TEPCs) is still debated. Using an exclusively in vivo approach, we show that quiescent UEA1– TECs actively proliferate during thymic regeneration in 6-month-old mice and possessed a MHCIIlo Sca1hi CD49fhi CD24lo Plet1– phenotype. We then performed RNA sequencing of UEA1- quiescent (label-retaining cells, called LRCs) cells and compared them to UEA1- GFP- (nonquiescent, NonLRCs) TECs. Overall design: We analyzed 2 samples with one replicate each. Each sample contains pooled cells isolated from 11 mice to reach a minimum of 10000 cells/replicate.
Detection of Quiescent Radioresistant Epithelial Progenitors in the Adult Thymus.
Specimen part, Subject
View SamplesmESCs cultured in microfluidic chambers secrete endogneous signals which accumulate to facilitate expression of pluripotency associated genes
Embryonic Stem Cells Cultured in Microfluidic Chambers Take Control of Their Fate by Producing Endogenous Signals Including LIF.
Cell line
View SamplesRadiation is an established cause of thyroid cancer and growing evidence supports a role for H2O2 in spontaneous thyroid carcinogenesis. Little is known about the molecular programs activated by these agents in thyroid cells. We profiled the DNA damage response and cell death induced by -radiation (0.15Gy) and H2O2 (0.00250.3mM) in primary human thyroid cells and T-cells. While the two cell types had more comparable radiation responses, 3- to 10-fold more H2O2 was needed to induce detectable DNA damage in thyrocytes. At H2O2 and radiation doses incurring double-strand breaks (DSB), cell death occurred after 24hrs in T-cells, but not in thyrocytes. We next prepared thyroid and T-cells primary cultures from 8 donors operated for non-cancerous pathologies and profiled their genome-wide transcriptional response 4hr after: 1) exposure to 1 Gy radiation, 2) treatment with H2O2, or 3) no treatment. Two H2O2 doses were investigated, calibrated in each cell type as to elicit levels of single- and double-strand breaks equivalent to 1 Gy -radiation. The transcriptional responses of thyrocyte and T-cells to radiation were similar, involving DNA repair and cell death genes. In addition to this transcriptional program, H2O2 also upregulated antioxidant genes in thyrocytes, including glutathione peroxidases (GPx) at the DSB-inducing dose. By contrast, a transcriptional storm involving thousands of genes was raised in T-cells. Finally, we showed that GPx inhibition reduced the DNA damaging effect of H2O2 in thyrocytes. We conjecture that defects of anti- H2O2 protection could promote spontaneous thyroid cancers.
Comparative analysis of the thyrocytes and T cells: responses to H2O2 and radiation reveals an H2O2-induced antioxidant transcriptional program in thyrocytes.
Sex, Age, Treatment, Subject
View SamplesIn mammals, nicotinamide phosphoribosyltransferase (NAMPT) and nicotinamide mononucleotide adenylyltransferase 1 (NMNAT-1) constitute a nuclear NAD+ salvage pathway, regulating cellular functions of the NAD+-dependent deacetylase SIRT1. However, little is known about the molecular mechanisms by which NAD+ biosynthesis controls gene transcription in the nucleus. In this study, we show that stable knockdown of NAMPT or NMNAT-1 in MCF-7 breast cancer cells significantly reduced total cellular NAD+ levels. Expression microarray analyses demonstrate that both enzymes have broad and overlapping functions in gene regulation. SIRT1 is a key mediator of NAMPT- and NMNAT-1-dependent gene regulation, and is found at promoters of many of the target genes. Furthermore, SIRT1 deacetylase activity at these promoters is regulated by NAMPT and NMNAT-1. Most significantly, NMNAT-1 interacts with SIRT1 and is recruited to target gene promoters by SIRT1. Our results reveal an unexpected mechanism for the direct control of SIRT1 deacetylase activity at target gene promoters by NMNAT-1. Interactions between NMNAT-1 and SIRT1 at gene promoters may provide a platform for integration of multiple signaling pathways that regulate transcription.
Enzymes in the NAD+ salvage pathway regulate SIRT1 activity at target gene promoters.
No sample metadata fields
View SamplesNMNAT1 is a nuclear enzyme in the mammalian NAD+ salvage pathway. Expression microarray analysis was used to study the effect of NMNAT1 knockdown on gene expression in MCF-7 breast cancer cells.
Enzymes in the NAD+ salvage pathway regulate SIRT1 activity at target gene promoters.
No sample metadata fields
View SamplesLow levels of MYB promote the development of myeloproliferative neoplasm (MPN). The cell type identified that can transplant the MPN phenotype has been identified as expressing KIT, CD11b and low levels of lineage markers (K11bL).
Transcriptional regulation of SPROUTY2 by MYB influences myeloid cell proliferation and stem cell properties by enhancing responsiveness to IL-3.
Sex, Age, Specimen part
View SamplesSIRT1 is a nuclear NAD+-dependent protein deacetylase. Expression microarray analysis was used to study the effect of SIRT1 knockdown on gene expression in MCF-7 breast cancer cells.
Enzymes in the NAD+ salvage pathway regulate SIRT1 activity at target gene promoters.
No sample metadata fields
View SamplesNAMPT is an enzyme in the mammalian NAD+ salvage pathway. Expression microarray analysis was used to study the effect of NAMPT knockdown on gene expression in MCF-7 breast cancer cells.
Enzymes in the NAD+ salvage pathway regulate SIRT1 activity at target gene promoters.
No sample metadata fields
View Samples