Repetitive sequences derived from transposons make up a large fraction of eukaryotic genomes and must be silenced to protect genome integrity. Repetitive elements are often found in heterochromatin; however, the roles and interactions of heterochromatin proteins in repeat regulation are poorly understood. Here we show that a diverse set of C. elegans heterochromatin proteins act together with the piRNA and nuclear RNAi pathways to silence repetitive elements and prevent genotoxic stress in the germ line. Mutants in genes encoding HPL-2/HP1, LIN-13, LIN-61, LET-418/Mi-2, and H3K9me2 histone methyltransferase MET-2/SETDB1 also show functionally redundant sterility, increased germline apoptosis, DNA repair defects, and interactions with small RNA pathways. Remarkably, fertility of heterochromatin mutants could be partially restored by inhibiting cep-1/p53, endogenous meiotic double strand breaks, or the expression of MIRAGE1 DNA transposons. Functional redundancy among these factors and pathways underlies the importance of safeguarding the genome through multiple means. Overall design: Synchronized, starved L1 stage worms were grown on NGM plates under one of two conditions. Condition 1: growth was at 20°C (hpl-2, let-418, lin-61, met-2 set-25, and wild-type N2) until the L4 stage and then worms were shifted to 25°C for 15-18 hours until they reached young adult stage. Condition 2: growth was at 15°C (lin-13, prg-1, nrde-2, nrde-2; let-418, and wild-type N2) until the L4 stage, and then worms were shifted to 25°C for 15-18 hours until they reached young adult stage. Worms were then washed off plates, flash frozen in liquid nitrogen, and stored at -80°C until use. RNA was extracted from frozen worms using TriPure (Roche). RNA was purified with Zymo Research RNA Clean and Concentrator-5 (Cambridge Bioscience) following DNase I digestion. Ribosomal RNA was depleted using Ribo-Zero rRNA Removal Kit (Human/Mouse/Rat) (Illumina). Libraries were prepared using the NEBNext Ultra Directional RNA Library Prep Kit for Illumina (New England Biolabs). Two biological replicates were prepared for each strain.
A team of heterochromatin factors collaborates with small RNA pathways to combat repetitive elements and germline stress.
Specimen part, SubjectView Samples
An essential step for understanding the transcriptional circuits that control development and physiology is the global identification and characterization of regulatory elements. Here we present the first map of regulatory elements across the development and ageing of an animal, identifying 42,245 elements accessible in at least one C. elegans stage. Based on nuclear transcription profiles, we define 15,918 protein-coding promoters and 17,918 putative enhancers, and find that both types of element can drive orientation-independent transcription. Additionally, hundreds of promoters produce transcripts antisense to protein coding genes, suggesting involvement in a widespread regulatory mechanism. We find that the accessibility of most elements is regulated during development and/or ageing and that patterns of accessibility change are linked to specific developmental or physiological processes. The map and characterization of regulatory elements across C. elegans life provides a platform for understanding how transcription controls development and ageing. Overall design: Capped nuclear RNA-seq of wild-type and glp-1 was performed to monitor transcription elongation across C. elegans development and ageing. Two biological replicates were done for each time point (six developmental stages and five ageing timepoints).
Chromatin accessibility dynamics across <i>C. elegans</i> development and ageing.
Cell line, SubjectView Samples
CD4+ T cells optimize the cytotoxic T cell (CTL) response in magnitude and quality, by unknown molecular mechanisms. We here present the transcriptomic changes, resulting from CD4+ T-cell help during priming, as apparent in effector CTLs. This gene expression signature reveals that CD4+ T-cell help optimizes CTLs in the expression of cytotoxic effector molecules, but also in many other functions that ensure optimal efficacy of CTLs throughout their life cycle. Overall design: Whole transcriptome analysis of effector CD8 T cells primed in the presence or absence of CD4 T cell help after vaccination or virus infection, or treated with agonistic CD27 or blocking CD70 antibody after vaccination.
CD4<sup>+</sup> T Cell Help Confers a Cytotoxic T Cell Effector Program Including Coinhibitory Receptor Downregulation and Increased Tissue Invasiveness.
Specimen part, Cell line, SubjectView Samples
We have previously demonstrated that bone marrow-derived DC can prevent diabetes development and halt progression of insulitis in NOD mice, the mouse model of type 1 diabetes (T1D). The DC population that was most effective in this therapy had a mature phenotype, expressed high levels of costimulatory molecules and secreted low levels of IL-12p70. The protective DC therapy induced regulatory Th2 cells that shifted the dominant Th1 environment, present in NOD mice, to a mixed Th1/Th2 milieu. Microarray analysis of therapeutic and non-therapeutic DC populations revealed several novel molecules that could play important roles in the observed DC-mediated therapy. The therapeutic DC population expressed a unique pattern of costimulatory molecules and chemokines, which were confirmed by flow cytometry and ELISA assays. We have performed in vitro chemotaxis assays that demonstrated the therapeutic DC preferentially attracted Th2 cells, as compared to Th1, Treg or nave T cells. In addition we quantified the in vivo migration of activated islet-specific T cells to the pancreas using novel cell labeling techniques and 19F nuclear magnetic resonance. A subcutaenous injection of therapeutic DC alters the migration of both Th1 and Th2 cells to the pancreas, and Th1 cells appeared in the lymph node draining the site of DC injection. These results suggest that the therapeutic function of DC is mediated in part by the chemoattractive properties of these DC for diabetogenic Th1 cells.
Gene expression analysis of dendritic cells that prevent diabetes in NOD mice: analysis of chemokines and costimulatory molecules.
The disrupted genetic mechanisms underlying neural abnormalities in Autism Spectrum Disorder remain mostly unknown and speculative. No biological marker nor genetic signature is currently available to assist with early diagnosis.
Prediction of autism by translation and immune/inflammation coexpressed genes in toddlers from pediatric community practices.
Sex, Specimen partView Samples
Analysis of 2 cultured normal lung cell lines, Normal Human Bronchial Epithelial (NHBE) and Human Small Airway Epithelial (SAEC) cells (Lonza, Walkersville, MD), following treatment with 5-aza-dC to induce DNA demethylation. These results provide insight into the role of epigenetic alterations, specifically demethylation, in differential gene expression in various lung neoplasms.
Integrative discovery of epigenetically derepressed cancer testis antigens in NSCLC.
Specimen part, Cell lineView Samples
Small intestine of a pool of three Wt mice and a pool of 3 IL-9tg mice in a balb/c backround.
IL-9- and mast cell-mediated intestinal permeability predisposes to oral antigen hypersensitivity.
No sample metadata fieldsView Samples
We report the transcriptional changes in Drosophila after administration of Actin or buffer control Overall design: Examination of transcriptional responses to actin versus buffer injected flies at 3,6 and 24 hours post injection (each time point includes triplicate samples)
Actin is an evolutionarily-conserved damage-associated molecular pattern that signals tissue injury in <i>Drosophila melanogaster</i>.
Sex, Specimen part, Cell line, SubjectView Samples
Activation of inflammatory pathways in human IBD. Leukocyte recruitment pathways including those for eosiniphils are activated in the affected colon in IBD. However, the functional implications of this are not known. We hypothesized that pro-inflammatory eotaxin (CCL11) dependent networks would be up regulated in the colon of pediatric patients with Ulcerative Colitis (UC), and that these would regulate eosinophil recruitment to the gut. These experiments tested differential colon gene expression relative to these pathways in healthy and UC samples. Colon biopsy samples were obtained from UC patients at diagnosis, and healthy controls. The global pattern of gene expression was determined using GeneSpring software, and biological networks were identified using Ingenuity software. Data suggested that a leukocyte recruitment network which includeds CCL11 is up regulated in pediatric UC at diagnosis. The degree of up regulation of these genes compared to healthy controls was remarkably conserved within the UC patient group, suggesting common mechanisms of mucosal inflammation.
Intestinal macrophage/epithelial cell-derived CCL11/eotaxin-1 mediates eosinophil recruitment and function in pediatric ulcerative colitis.
No sample metadata fieldsView Samples
This SuperSeries is composed of the SubSeries listed below.
Obesity accelerates epigenetic aging of human liver.
Sex, Age, Disease, SubjectView Samples