In this report, we have found that gata1 expressing erythroid cells contribute to a significant proportion of total body oxidative stress when animals were exposed to a strong pro-oxidant. RNA-seq of zebrafish under oxidative stress revealed the induction of tp53. Zebrafish carrying tp53 with mutation in its DNA binding domain were acutely sensitive to pro-oxidant exposure and displayed significant reactive oxygen species (ROS) and tp53-independent erythroid cell death resulting in an edematous phenotype. We found that a major contributing factor to ROS was increased basal mitochondrial respiratory rate without reserve. These data add to the concept that tp53, while classically a tumor suppressor and cell cycle regulator, has additional roles in controlling cellular oxidative stress. Overall design: We performed RNA-seq in two experiments. (1) Wild-type zebrafish embryos were exposed to 1-naphthol (vs no exposure) from 24 - 72 hpf (n = 5/group). (2) tp53 mutant zebrafish embryos were exposed to 1-naphthol (vs no exposure) from 24 - 72 hpf (n = 5/group).
TP53 Modulates Oxidative Stress in Gata1<sup>+</sup> Erythroid Cells.
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The complete transcriptomes of kidney cortex from 3 ?-HIF2aM3 18 month old TG+ male mice and 3 age matched wild type (WT) C57BL/6 male mice were sequenced on an Illumina HiSeq2000 Sequencer. Overall design: Examination of complete transcriptome of kidney cortex between ?-HIF2aM3 TG+ male mice and wild type C57BL/6 male mice
Activation of HIF2α in kidney proximal tubule cells causes abnormal glycogen deposition but not tumorigenesis.
Sex, Specimen part, Cell line, SubjectView Samples
Chronic alcohol consumption can lead to alchohol-related brain damage (ARBD). Despite the well known acute effects of alcohol the mechanism responsible for chronic brain damage is largely unknown. Pathologically the major change is the loss of white matter while neuronal loss is mild and restricted to a few areas such as the prefrontal cortex. In order to improve our understanding of ARBD pathogenesis we used microarrays to explore the white matter transcriptome of alcoholics and controls.
Comorbidities, confounders, and the white matter transcriptome in chronic alcoholism.
Specimen part, Disease, Disease stageView Samples
The transcription factor Helios is expressed in a large subset of Foxp3+ Tregs of both mouse and man. We previously demonstrated that Treg induced in peripheral sites (pTreg) from Foxp3- T conventional (Tconv) cells were Helios- and proposed that Helios is a marker of thymic derived Treg (tTreg). To compare the two Treg subpopulations, we generated Helios-GFP reporter mice and crossed them to Foxp3-RFP reporter mice. The Helios+ Treg population expressed a more activated phenotype and had a higher suppressive capacity in vitro. Both populations expressed a highly demethylated TSDR and both subsets were equivalent in their ability to suppress inflammatory bowel disease in vivo. However, Helios+ Treg more effectively inhibited the proliferation of activated, autoreactive splenocytes from scurfy mice. When Helios+ and Helios- Treg were transferred to lymphoreplete mice, both populations maintained comparable Foxp3 expression, but Foxp3 expression was less stable in Helios- Treg when transferred to lymphopenic mice. Gene expression profiling of the two populations demonstrated a large number of differentially expressed genes and that Helios- Treg subpopulation expressed certain genes normally expressed in CD4+Foxp3- T cells. TCR repertoire analysis indicated very little overlap between Helios+ and Helios- Treg. Thus, Helios+ and Helios- Treg subpopulations are phenotypically and functionally distinct, consistent with thymic and peripheral sites of origin, respectively. Because of their superior suppressive activity and enhanced stability Foxp3+Helios+ Treg represent the optimal Treg population for cellular immunotherapy. Overall design: 5 replicates of wildtype vs knockout Helios gene in Treg cells.
Helios<sup>+</sup> and Helios<sup>-</sup> Treg subpopulations are phenotypically and functionally distinct and express dissimilar TCR repertoires.
Specimen part, SubjectView Samples
In gastrulation, distinct progenitor cell populations are induced and sorted into the three germ layers ectoderm, mesoderm and endoderm. In order to identify genes involved in germ layer specification and morphogenesis, we identified genes differentially expressed between ectodermal and mesendodermal progenitor cells. To do so, we first generated highly enriched pools of ectodermal and mesendodermal progenitor cells. Mesendodermal cells were generated by over-expressing the Nodal signal Cyclops in wild type embryos and ectodermal cells were taken from mz-one-eyed-pinhead (oep) mutant embryos. We then compared the transcriptome of ectodermal versus mesendodermal cells taken from embryos at 7 hours post fertilization (hpf). In wild type embryos at this stage (70% epiboly), the first ectodermal and mesendodermal progenitor cells have already been sorted into their respective germ layers and ingression of mesendodermal progenitors is still ongoing.
Identification of regulators of germ layer morphogenesis using proteomics in zebrafish.
Age, Specimen part, Subject, TimeView Samples
Damage-associated molecular pattern (DAMP) molecules S100A8 and S100A9 with well-known functions in inflammation, tumor growth and metastasis. It has been found to have promote tumor cell proliferation activity at low concentration . However, the mechanism underlying this remains unclear. In the current study, we performed genome expression profiling analysis using the Affymetrix genome wide microarray system to identify broad scale changes in gene expression associated with S100a8 or S100a9 recombinant protein stimulation in murine colon carcinoma cell line CT26.WT.
Inflammation-induced S100A8 activates Id3 and promotes colorectal tumorigenesis.
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The intestinal epithelium constitutes a crucial defense to the potentially life-threatening effects of gut microbiota. However, due to a complex underlying vasculature, hypoperfusion and resultant tissue ischemia pose a particular risk to function and integrity of the epithelium. The small ubiquitin-like modifier (SUMO) conjugation pathway critically regulates adaptive responses to metabolic stress and is of particular significance in the gut, as inducible knockout of the SUMO-conjugating enzyme Ubc9 results in rapid intestinal epithelial disintegration. Here we analyzed the pattern of individual SUMO isoforms in intestinal epithelium and investigated their roles in intestinal ischemia/reperfusion (I/R) damage. Immunostaining revealed that epithelial SUMO2/3 expression was almost exclusively limited to crypt epithelial nuclei in unchallenged mice. However, intestinal I/R or overexpression of Ubc9 caused a remarkable enhancement of epithelial SUMO2/3 staining along the crypt-villus axis. Unexpectedly, a similar pattern was found in SUMO1 knockout mice. Ubc9 transgenic mice, but also SUMO1 knockout mice were protected from I/R injury as evidenced by better preserved barrier function and blunted inflammatory responses. PCR array analysis of microdissected villus-tip epithelia revealed a specific epithelial contribution to reduced inflammatory responses in Ubc9 transgenic mice, as key chemotactic signaling molecules such as IL17A were significantly downregulated. Together, our data indicate a critical role particularly of the SUMO2/3 isoforms in modulating responses to I/R and provide the first evidence that SUMO1 deletion activates a compensatory process that protects from ischemic damage.
Ubc9 overexpression and SUMO1 deficiency blunt inflammation after intestinal ischemia/reperfusion.
The goal of this study was to compare mRNA from mammary epithelial cells of 3 mammary-specific Nmi knockout FVB with corresponding wildtype control. This was performed to obtain clues to the signaling pathways that were impacted in the mammary epithelial cells upon knocking-out Nmi expression. Overall design: To determine how the loss of Nmi contributed to a hyper-proliferative phenotype during puberty and lactation, we performed global RNAseq analysis from enriched mammary epithelial organoids from lactation day1 (L1), the time when Nmi protein expression in normal mammary epithelium is at its highest level. We compared 2 groups with 3 mice/group. We used second and third mammary glands of each mouse. These glands were isolated from mice on the first day of lactation, minced and dissociated in digestion medium (HBSS containing collagenase I (Sigma Aldrich, St. Louis, MO) (1mg/mL) and Pronase (Sigma Aldrich) (0.1mg/mL)) for two hours at 37C with shaking. Epithelial organoids were washed in PBS and enriched by pulse centrifugation to 1500rpm at least three times before subsequent assays.
Conditional knockout of N-Myc and STAT interactor disrupts normal mammary development and enhances metastatic ability of mammary tumors.
Specimen part, SubjectView Samples
Low affinity Tregs are important for controlling autoimmune diabetes. Overall design: High and low affinity Tregs were isolated from the spleen and pancreatic islets of two-TCR retrogenic mice expressing the insulin-specific TCRs 4-8 and 12-4.4m1.
Cutting Edge: Low-Affinity TCRs Support Regulatory T Cell Function in Autoimmunity.
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Aims: To map histone modifications with unprecedented resolution both globally and locus-specifically, and to link modification patterns to gene expression. Materials & methods: Using correlations between quantitative mass spectrometry and chromatin immunoprecipitation/microarray analyses, we have mapped histone post-translational modifications in fission yeast (Schizosaccharomyces pombe). Results: Acetylations at lysine 9, 18 and 27 of histone H3 give the best positive correlations with gene expression in this organism. Using clustering analysis and gene ontology search tools, we identified promoter histone modification patterns that characterize several classes of gene function. For example, gene promoters of genes involved in cytokinesis have high H3K36me2 and low H3K4me2, whereas the converse pattern is found ar promoters of gene involved in positive regulation of the cell cycle. We detected acetylation of H4 preferentially at lysine 16 followed by lysine 12, 8 and 5. Our analysis shows that this H4 acetylation bias in the coding regions is dependent upon gene length and linked to gene expression. Our analysis also reveals a role for H3K36 methylation at gene promoters where it functions in a crosstalk between the histone methyltransferase Set2KMT3 and the histone deacetylase Clr6, which removes H3K27ac leading to repression of transcription. Conclusion: Histone modification patterns could be linked to gene expression in fission yeast.
Genome-wide mapping of histone modifications and mass spectrometry reveal H4 acetylation bias and H3K36 methylation at gene promoters in fission yeast.
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