Systemic lupus erythematosus (SLE) is an autoimmune disorder characterized by the production of antibodies to self-nucleic acids, immune complex deposition and tissue inflammation such as glomerulonephritis. Innate recognition of molecular complexes containing self-DNA and RNA and the ensuing production of type I interferons (IFN) contribute to SLE development. Plasmacytoid dendritic cells (pDCs) have been proposed as a relevant source of pathogenic IFN in SLE; however, their net contribution to the disease remains unclear. We addressed this question using haplodeficiency of the pDC-specific transcription factor E2-2 (Tcf4), which causes a specific impairment of pDC function in otherwise normal animals. We report that Tcf4+/- animals were significantly protected from SLE-like disease caused by the overexpression of the endosomal RNA sensor Tlr7. The protection was also observed after the monoallelic deletion of Tcf4 specifically in the dendritic cell lineage. Furthermore, Tcf4 haplodeficiency in the B6.Sle1.Sle3 multigenic model of SLE ameliorated key disease manifestations including anti-DNA antibody production, immune activation and glomerulonephritis. These results provide genetic evidence that pDCs are critically involved in SLE pathogenesis, confirming their potential utility as therapeutic targets in the disease.
Genetic evidence for the role of plasmacytoid dendritic cells in systemic lupus erythematosus.
Sex, Specimen part
View SamplesMetastasis is the leading cause of death for cancer patients. Consequently it is imperative that we improve our understanding of the molecular mechanisms that underlie progression of tumour growth towards malignancy. Advances in genome characterisation technologies have been very successful in identifying commonly mutated or misregulated genes in a variety of human cancers. However the difficulty in evaluating whether these candidate genes drive tumour progression remains a major challenge. Using the genetic amenability of Drosophila melanogaster we generated tumours with specific genotypes in the living animal and carried out a detailed systematic loss-of-function analysis to identify conserved genes that enhance or suppress epithelial tumour progression. This enabled the discovery of functional cooperative regulators of invasion and the establishment of a network of conserved invasion suppressors. This includes constituents of the cohesin complex, which can either promote individual or collective invasion, depending on the severity of effect on cohesin function.
A Genetic Analysis of Tumor Progression in Drosophila Identifies the Cohesin Complex as a Suppressor of Individual and Collective Cell Invasion.
Cell line
View SamplesWe performed RNAseq on l(3)mbt mutant somatic ovaries to gain a genome-wide view of tissue-specific gene expression changes in L(3)mbt-depleted somatic ovaries. Overall design: Examination of gene expression changes in mutant and control somatic ovaries.
L(3)mbt and the LINT complex safeguard cellular identity in the <i>Drosophila</i> ovary.
Specimen part, Subject
View SamplesWe analyzed the genome-wide expression by RNA-seq of a yeast strain that expresses Cas9d and a guideRNA targeted to the GAL10 locus (called +116), which inhibits GAL10 ncRNA expression from the antisense strand. We compared this strain to a strain expressing a scrambled guideRNA. The goal was to examine the effects of ncRNA inhibition and to examine if CRISPR inhibition of gene expression has off-target effects. We find that CRISPR-mediated inhibtion of GAL10 ncRNA only significantly changes expression of transcripts at the GAL1-10 locus, showing that CRISPR is highly specific, and that GAL10 ncRNA only control genes at the GAL locus. Overall design: RNA-seq of 2 strains with CRISPR scrambled and 2 strains with CRISPR +116, the latter of which inhibits GAL10 ncRNA
Single-Molecule Imaging Reveals a Switch between Spurious and Functional ncRNA Transcription.
Cell line, Subject
View SamplesWhile the hypothalamo-pituitary-adrenal axis (HPA) activates a general stress response by increasing glucocorticoid (Gc) synthesis, biological stress resulting from infections triggers the inflammatory response through production of cytokines. The pituitary gland integrates some of these signals by responding to the pro-inflammatory cytokines IL6 and LIF and to a negative Gc feedback loop. The present work used whole-genome approaches to define the LIF/STAT3 regulatory network and to delineate cross-talk between this pathway and Gc action. Genome-wide ChIP-chip identified 3 449 STAT3 binding sites, whereas 2 396 genes regulated by LIF and/or Gc were found by expression profiling. Surprisingly, LIF on its own changed expression of only 85 genes but the joint action of LIF and Gc potentiated the expression of more than a thousand genes. Accordingly, activation of both LIF and Gc pathways also potentiated STAT3 and GR recruitment to many STAT3 targets. Our analyses revealed an unexpected gene cluster that requires both stimuli for delayed activation: 83% of the genes in this cluster are involved in different cell defense mechanisms. Thus, stressors that trigger both general stress and inflammatory responses lead to activation of a stereotypic innate cellular defense response.
Regulatory network analyses reveal genome-wide potentiation of LIF signaling by glucocorticoids and define an innate cell defense response.
Specimen part, Time
View SamplesHigh endothelial venules (HEVs) are specialized blood vessels allowing recirculation of naïve lymphocytes through lymphoid organs. Here, using full length single-cell RNA sequencing, RNA-FISH, flow cytometry and immunohistofluorescence, we reveal the heterogeneity of HEVs in adult mouse peripheral lymph nodes (PLNs) under conditions of homeostasis, antigenic stimulation and after inhibition of lymphotoxin-b receptor (LTbR) signaling. We demonstrate that HEV endothelial cells are in an activated state during homeostasis, and we identify the genes characteristic of the differentiated HEV phenotype. We show that LTbR signaling regulates many HEV genes and pathways in resting PLNs, and that immune stimulation induces a global and temporary inflammatory phenotype in HEVs without compromising their ability to recruit naïve lymphocytes. Most importantly, we uncover differences in the regulation of genes controlling lymphocyte trafficking, Glycam1, Fut7, Gcnt1, Chst4, B3gnt3 and Ccl21a, that have implications for HEV function and regulation in health and disease. Overall design: Comparison of High Endothelial Cells and Blood Endothelial Cells from mouse lymph nodes under 4 different conditions with a total of 220 single cells.
Single-Cell Analysis Reveals Heterogeneity of High Endothelial Venules and Different Regulation of Genes Controlling Lymphocyte Entry to Lymph Nodes.
Specimen part, Cell line, Subject
View Samples[Hela cells]: We performed cdr2 knockdown with a pool of 4 cdr2-specific siRNAs to test whether cdr2 may regulate c-myc target genes as cells passage through mitosis.
The onconeural antigen cdr2 is a novel APC/C target that acts in mitosis to regulate c-myc target genes in mammalian tumor cells.
Cell line
View SamplesThe Mre11 complex (Mre11, Rad50, and Nbs1) and Chk2 have been implicated in the DNA damage response, an inducible process required for the suppression of malignancy. The Mre11 complex is predominantly required for repair and checkpoint activation in S phase, while Chk2 governs apoptosis. We examined the relationship between the Mre11 complex and Chk2 in the DNA damage response via the establishment of Nbs1B/B Chk2-/- and Mre11ATLD1/ATLD1 Chk2-/- mice. Chk2 deficiency did not modify the checkpoint defects or chromosomal instability of Mre11 complex mutants; however, the double mutant mice exhibited synergistic defects in DNA damage-induced p53 regulation and apoptosis. Nbs1B/B Chk2-/- and Mre11ATLD1/ATLD1 Chk2-/- mice were also predisposed to tumors. In contrast, DNA-PKcs deficient mice, in which G1-specific chromosome breaks are present, did not exhibit synergy with Chk2-/- mutants. These data suggest that Chk2 suppresses the oncogenic potential of DNA damage arising during S and G2 phases of the cell cycle.
Chk2 suppresses the oncogenic potential of DNA replication-associated DNA damage.
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View SamplesAortic valve regurgitation (AR) imposes a severe volume overload to the left ventricle (LV) which results in dilation, eccentric hypertrophy and eventually loss of function. Little is known about the impact of AR on LV gene expression. We therefore conducted a gene expression profiling study in the LV of male Wistar rats with chronic (9 months) and severe AR.
Multiple short-chain dehydrogenases/reductases are regulated in pathological cardiac hypertrophy.
Sex
View SamplesADAMs are transmembrane metalloproteases that control cell behavior by cleaving both cell adhesion and signaling molecules. The cytoplasmic domain of ADAMs can regulate the proteolytic activity by controlling the subcellular localization and/or the activation of the protease domain. Here we show that the cytoplasmic domain of ADAM13 is cleaved and translocates into the nucleus. Preventing this translocation renders the protein incapable of promoting cranial neural crest (CNC) cell migration in vivo, without affecting its proteolytic activity. In addition, the cytoplasmic domain of ADAM13 regulates the expression of multiple genes in the CNC. This study shows that the cytoplasmic domain of ADAM metalloproteases can perform essential functions in the nucleus of cells and may contribute substantially to the overall function of the protein.
Translocation of the cytoplasmic domain of ADAM13 to the nucleus is essential for Calpain8-a expression and cranial neural crest cell migration.
Specimen part
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