The study demontrates differences in the transcriptome ( both of protein coding transcripts and long non-coding RNAs) in the unilateral ureteric obstruction model of renal fibrosis. Overall design: Renal tissue was studied from animals undergoing sham operation (as controls) or right ureteric ligation. Animals were sacrificed 2 and 8 days following ligation and the right kidney tissue was examined.
Whole-transcriptome analysis of UUO mouse model of renal fibrosis reveals new molecular players in kidney diseases.
Sex, Age, Specimen part, Cell line, Subject
View SamplesSecretion of insulin by pancreatic cells in response to glucose is central for glucose homeostasis, and dysregulation of this process is a hallmark of the early stages of diabetes. We utilized a tetracycline-inducible approach to investigate the immediate impact of a pulse of Sox17 expression on the insulin secretory pathway. Sox17 gain-of-function animals (Sox17-GOF) were generated using an Ins2-rtTA mouse line and a line in which Sox17 expression is regulated by the tetracycline transactivator (tetO-Sox17). Administering doxycycline to 16-week old mice resulted in Sox17 overexpression in mature cells in the islets.
Sox17 regulates insulin secretion in the normal and pathologic mouse β cell.
Age, Specimen part
View Samplesβ cell apoptosis and dedifferentiation are two hotly-debated mechanisms underlying β cell loss in type 2 diabetes (T2D); however, the molecular drivers underlying such events remain largely unclear. Here, by performing a side-by-side comparison of mice carrying β cell-specific deletion of endoplasmic reticulum (ER)-associated degradation (ERAD) and autophagy, we report that while autophagy appears necessary for β cell survival, the highly conserved Sel1L-Hrd1 ERAD protein complex is required for the maintenance of β cell maturation and identity. Notably, SEL1L expression is significantly reduced in human T2D islets compared to healthy human islets. At the single cell level, we demonstrate that Sel1L deficiency is not associated with β cell loss, but rather loss of β cell identity. Mechanistically, we find that Sel1L-Hrd1 ERAD controls β cell identity via TGFβ signaling, in part by mediating the degradation of TGF-β receptor 1 (TGFβRI). Inhibition of TGFβ signaling in Sel1L-deficient β cells augments the expression of β cell maturation markers and increases the total insulin content. Our data reveal profound but distinct pathogenic effects of two major proteolytic pathways in β cells, providing a new framework for therapies targeting distinct mechanisms of protein quality control.
Sel1L-Hrd1 ER-associated degradation maintains β cell identity via TGF-β signaling.
Sex, Specimen part
View SamplesDendritic cells (DCs) are critical mediators of host defense against bacteria. The goal of this microarray study was to understand the global transcriptional response of bone marrow-derived dendritic cells (BMDCs) upon exposure to live bacteria, to better understand how DCs orchestrate a host-protective immune response. We found that BMDCs upregulate a number of critical immune-related genes upon exposure to live E. coli. Most notably, the gene encoding hepcidin, a critical regulator of mammalian iron homeostasis, was significantly upregulated in BMDCs upon exposure to live bacteria.
Dendritic cell-derived hepcidin sequesters iron from the microbiota to promote mucosal healing.
Specimen part
View SamplesFoxp3+ regulatory T cells (Treg cells) maintain immunological tolerance and their deficiency results in fatal multi-organ autoimmunity. Although heightened T cell receptor (TCR) signaling is critical for the differentiation of Treg cells, the role of TCR signaling in Treg cell function remains largely unknown. Here we demonstrate inducible ablation of the TCR results in Treg cell dysfunction which cannot be attributed to impaired Foxp3 expression, decreased expression of Treg cell signature genes or altered ability to sense and consume interleukin 2. Rather, TCR signaling was required for maintaining the expression of a limited subset of genes comprising 25% of the activated Treg cell transcriptional signature. Our results reveal a critical role for the TCR in Treg cell suppressor capacity.
Continuous requirement for the TCR in regulatory T cell function.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Inflammation-induced repression of chromatin bound by the transcription factor Foxp3 in regulatory T cells.
Specimen part
View SamplesThe transcription factor Foxp3 is indispensable for the ability of regulatory T (Treg) cells to suppress fatal inflammation. Here, we characterized the role of Foxp3 in chromatin remodeling and regulation of gene expression in actively suppressing Treg cells in an inflammatory setting. Although genome-wide Foxp3 occupancy of DNA regulatory elements was similar in resting and in vivo activated Treg cells, Foxp3-bound enhancers were poised for repression only in activated Treg cells. Following activation, Foxp3-bound sites showed reduced chromatin accessibility and selective H3K27 tri-methylation, which was associated with Ezh2 recruitment and downregulation of nearby gene expression. Thus, Foxp3 poises its targets for repression by facilitating formation of repressive chromatin in regulatory T cells upon their activation in response to inflammatory cues.
Inflammation-induced repression of chromatin bound by the transcription factor Foxp3 in regulatory T cells.
Specimen part
View SamplesRNA-Seq analysis of Treg cell subsets isolated from lungs of Il10GFPFoxp3Thy1.1 mice. Thy1.1+ Treg cells were FACS-sorted into IL-10–IL-18R–, IL-10+IL-18R– and IL10–IL-18R+ populations on day 5 following intranasal infection with 0.5 LD50 PR8-OTI influenza virus. Overall design: mRNA profiles of each Thy1.1+ Treg cell population (IL-10–IL-18R–, IL-10+IL-18R– and IL10–IL-18R+) from lungs on day 5 following influenza infection from 5 infected mice, sorted into TRIzol LS reagent.
A Distinct Function of Regulatory T Cells in Tissue Protection.
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View SamplesIron is an essential component of the erythrocyte protein hemoglobin and is crucial to oxygen transport in vertebrates. In the steady state, erythrocyte production is in equilibrium with erythrocyte removal1. In various pathophysiological conditions, erythrocyte life span is severely compromised, which threatens the organism with anemia and iron toxicity 2,3. Here we identify anon-demand mechanism specific to the liver that clears erythrocytes and recycles iron. We showthat Ly-6Chigh monocytes ingest stressed and senescent erythrocytes, accumulate in the liver, and differentiate to ferroportin 1 (FPN1)-expressing macrophages that can deliver iron to hepatocytes. Monocyte-derived FPN1+ Tim-4neg macrophages are transient, reside alongside embryonically-derived Tim-4high Kuppfer cells, and depend on Csf1 and Nrf2. The spleenlikewise recruits iron-loaded Ly-6Chigh monocytes, but they do not differentiate into ironrecycling macrophages due to the suppressive action of Csf2, and are instead shuttled to the livervia coordinated chemotactic cues. Inhibiting this mechanism by preventing monocyte recruitment to the liver leads to kidney failure and liver damage. These observations identify the liver as the primary organ supporting emergency erythrocyte removal and iron recycling, and uncover a mechanism by which the body adapts to fluctuations in erythrocyte integrity.
On-demand erythrocyte disposal and iron recycling requires transient macrophages in the liver.
Specimen part
View SamplesLarge-scale cancer genomics projects are profiling hundreds of tumors at multiple molecular layers, including copy number, mRNA and miRNA expression, but the mechanistic relationships between these layers are often excluded from computational models. We developed a supervised learning framework for integrating molecular profiles with regulatory sequence information to reveal regulatory programs in cancer, including miRNA-mediated regulation. We applied our approach to 320 glioblastoma profiles and identified key miRNAs and transcription factors as common or subtype-specific drivers of expression changes. We confirmed that predicted gene expression signatures for proneural subtype regulators were consistent with in vivo expression changes in a PDGF-driven mouse model. We tested two predicted proneural drivers, miR-124 and miR-132, both underexpressed in proneural tumors, by overexpression in neurospheres and observed a partial reversal of corresponding tumor expression changes. Computationally dissecting the role of miRNAs in cancer may ultimately lead to small RNA therapeutics tailored to subtype or individual.
Inferring transcriptional and microRNA-mediated regulatory programs in glioblastoma.
Cell line
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