The goal of our study was to evaluate at the systems-level, the effect of sex hormones on thymic epithelial cells (TECs). To this end, we sequenced the transcriptome of cortical and medullary TECs (cTECs and mTECs) from three groups of 6 month-old mice: males, females and males castrated at four weeks of age. In parallel, we analyzed variations in the size of TEC subsets in those three groups between 1 and 12 months of age. We report that sex hormones have pervasive effects on the transcriptome of TECs: the number of differentially expressed genes was 1,440 in cTECs and 1,783 in mTECs. Sexual dimorphism was particularly conspicuous in cTECs. Male cTECs displayed low proliferation rates that correlated with low expression of Foxn1 and its main targets. Furthermore, male cTECs expressed relatively low levels of genes instrumental in thymocyte expansion (e.g., Dll4) and positive selection (Psmb11 and Ctsl). Nevertheless, cTECs were more abundant in males than females. Accumulation of cTECs in males correlated with differential expression of genes regulating cell survival and cell differentiation. Unexpectedly, we observed that female and male sex hormones repressed promiscuous gene expression in mTECs. Since sex hormones did not affect the expression of Aire per se, they must impinge on the activity of unidentified regulator(s) of promiscuous gene expression in mTECs. The sexual dimorphism of TECs highlighted here may be mechanistically linked to the well-recognized sex differences in susceptibility to infections and autoimmune diseases. Overall design: Cortical and medullary thymic epithelial cells from 6 month-old male, female and castrated male mice were sequenced in 3 replicates (but only 2 replicates for castrated male mTECs).
Thymic Mesenchymal Cells Have a Distinct Transcriptomic Profile.
No sample metadata fields
View SamplesThymocytes were extracted from a pool of three 8-12 week old C57BL-6 female mice. Cells were separated from stroma by gently crushing the thymi in between 2 microslides. RNA from thymocytes was extracted using the Trizol reagent and protocol, and analysed using the Illumina HiSeq 2000. Overall design: Transcriptomic analysis of a single replicate of thymocytes from a pool of three 8-12 week old C57BL-6 female mice, using the Illumina HiSeq 2000
Thymic Mesenchymal Cells Have a Distinct Transcriptomic Profile.
Specimen part, Cell line, Subject
View SamplesPurpose: 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 SamplesAs regulators of protein degradation, proteasomes regulate practically all cellular functions. It is therefore logical to assume that replacement of the constitutive proteasome (CP) by its IFN- inducible homolog immunoproteasome (IP) could have far reaching effects on cell function. Accordingly, recent studies have revealed important roles for IPs in immune cells beyond MHC I-peptide processing. Moreover, the expression of IPs in non-immune cells from non-inflamed tissues suggests that the involvement of IPs is not limited to the immune system. We demonstrate here that IP-deficiency affects the transcription of 8104 genes in maturing dendritic cells (DCs). This occurs mainly through non-redundant regulation of key immune-related transcription factors by CPs and IPs. Additionally, IP-deficiency decreases DC''s efficiency to activate CD8+ T cells in vivo. Our study reveals that the broad cellular roles of IPs could rely on transcription regulation and, more importantly, illustrates how IP-deficiency could generate MHC I-peptide processing-independent phenotypes. Overall design: Examination of the transcriptome of WT and immunoproteasome-deficient cells at 4 different time points of dendritic cell maturation, in 4 experimental replicates (total of 32 samples).
Immunoproteasomes shape the transcriptome and regulate the function of dendritic cells.
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View SamplesAcetylation and deacetylation of histones and other proteins depend on the opposing activities of histone acetyltransferases and histone deacetylases (HDACs), leading to either positive or negative gene expression changes. The use of HDAC inhibitors (HDACi) has uncovered a role for HDACs in the control of proliferation, apoptosis and inflammation. However, little is known of the roles of specific HDACs in intestinal epithelial cells (IEC). We investigated the consequences of ablating both Hdac1 and Hdac2 in murine IECs gene expression.
HDAC1 and HDAC2 restrain the intestinal inflammatory response by regulating intestinal epithelial cell differentiation.
Specimen part
View SamplesAlthough hepatocyte-nuclear-factor-1 (Hnf1) is crucial for pancreas and liver functions, it is believed to play a limited functional role for intestinal epithelial functions. The aim of this study was to assess the consequences of abrogating Hnf1 on the maintenance of adult small intestinal epithelial functions.
Loss of hepatocyte-nuclear-factor-1alpha impacts on adult mouse intestinal epithelial cell growth and cell lineages differentiation.
Age, Specimen part, Disease
View SamplesHepatocyte-nuclear-factor-4 (Hnf4) is a transcription factor that controls epithelial cell polarity and maturation during embryogenesis. Hnf4 conditional deletion during post-natal development results in minor consequences on intestinal epithelium integrity but promotes activation of the Wnt/-catenin pathway. Here we show that Hnf4 does not act as a tumor suppressor gene but is crucial to promote gut tumorigenesis in mice. Polyp multiplicity in ApcMin mice that lacks Hnf4 is suppressed in comparison to littermate ApcMin controls. Analysis of microarray gene expression profiles from mice lacking Hnf4 in the intestinal epithelium identifies its novel function in regulating the expression of reactive oxygen species (ROS) detoxifying genes. This role is supported with the demonstration that HNF4 is functionally involved in the protection against spontaneous and 5-fluorouracil chemotherapy-induced production of intracellular ROS in colorectal cancer cell lines. The analysis of a colorectal cancer patient cohort establishes that HNF4 is significantly up-regulated at both gene transcript and protein levels in tumors relative to adjacent benign epithelial resections. Several genes involved in ROS neutralization are also up-regulated in correlation with HNF4 expression. All together, the findings point to the nuclear receptor HNF4 as a potential therapeutic target to eradicate aberrant epithelial cell resistance to ROS production during intestinal tumorigenesis.
Hepatocyte nuclear factor-4alpha promotes gut neoplasia in mice and protects against the production of reactive oxygen species.
Specimen part
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 SamplesPurpose: Cortical thymic epithelial cells (cTECs) contain a unique type of proteasomes, thymoproteasomes. Indirect evidence suggests that the key role of PSMB11, a catalytic subunit of thymoproteasomes specific to cTECs, is to generate a unique repertoire of MHC I peptides. Notably, PSMB11-deficient mice display defective development of CD8 thymocytes. The objective of this study was to characterize the impact of PSMB11 on cTECs and thymocyte development. Since different types of proteasomes have non-redundant effects on gene expression, we hypothesized that thymoproteasomes should have a distinct impact on the transcriptome and thereby the function of cTECs. Results: We report that PSMB11 in cortical thymic epithelial cells has dramatic effects on cTECs on both CD4 and CD8 thymocyte populations. PSMB11 modulates the expression of 850 genes in cTECs, 582 in CD4 thymocytes and 284 in CD8 thymocytes. PSMB11-regulated cTEC genes are involved mainly in cell-cell adhesion, extracellular matric organization and thymocyte chemotaxis. PSMB11-deficient cTECs acquire features of mTECs and perturb thymocyte development. Deletion of PSMB11 causes a major cell stress in both CD4 and CD8 thymocyte populations. Of note, PSMB11-deficiency had no impact on medullary thymic epithelial cells (mTECs), which originate from progenitors that express PSMB11 early in ontogeny. Conclusion: We conclude that PSMB11 has pervasive effects on both CD4 and CD8 thymocytes via regulation of gene expression in cTECs. Overall design: We performed RNA-sequencing in triplicate on cTECs, mTECs, and SM, M1 and M2 thymocytes from the CD4 and CD8 lineages, in order to identify differential gene expression between WT and Psmb11-deficient mice.
PSMB11 Orchestrates the Development of CD4 and CD8 Thymocytes via Regulation of Gene Expression in Cortical Thymic Epithelial Cells.
Specimen part, Cell line, Subject
View SamplesObesity is a heterogeneous conditions comprising obese individuals with metabolic disorders (termed metabolically unhealthy obese; MUO) and obese individuals who are metabolically healthy (termed metabolically healthy obese; MHO).
Serum and adipose tissue amino acid homeostasis in the metabolically healthy obese.
Specimen part, Disease, Disease stage
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