We report the transcriptional response of the zebrafish digestive organs to an acute high-fat feed using RNASeq analysis and highlight the changes in gene expression involved in the synthesis, storage, and dispersal of lipids. These key physiological responses to a high-fat meal all stem from the endoplasmic reticulum (ER), where lipids are formed and assigned to their fates. Overall design: A feeding time course was undertaken with 6.5-dpf larval zebrafish. Triplicate samples were independently prepared from pairwise crosses fed either high-fat or low-fat food. 5% egg yolk emulsion (high-fat) feeds and 10% egg white (low-fat) feeds were prepared. At the appropriate time points, digestive organs (intestine, liver, pancreas) were dissected from 10 anesthetized larval zebrafish. Unfed controls were used to determine a transcriptional baseline.
Endoplasmic Reticulum Lipid Flux Influences Enterocyte Nuclear Morphology and Lipid-dependent Transcriptional Responses.
No sample metadata fields
View SamplesMalaria infection triggers vigorous host immune responses; however, the parasite ligands, host receptors and the signaling pathways responsible for these reactions remain unknown or controversial. Malaria parasites primarily reside within red blood cells (RBCs), thereby hiding themselves from direct contact and recognition by host immune cells. Host responses to malaria infection are very different from those elicited by bacterial and viral infections and the host receptors recognizing parasite ligands have been elusive. Here we investigated mouse genome-wide transcriptional responses to infections with two strains of Plasmodium yoelii (N67 and N67C) and discovered differences in innate response pathways corresponding to strain-specific disease phenotypes. Using in vitro RNAi gene knockdown and knockout mice, we demonstrated that a strong IFN-I response triggered by RNA Polymerase III and melanoma differentiation-associated protein 5 (MDA5), not Toll-like receptors (TLRs), binding of parasite DNA/RNA contributed to a decline of parasitemia in N67-infected mice. We showed that conventional dendritic cells were the major sources of early IFN-I, and that surface expression of phosphatidylserine (PS) on infected RBC (iRBC) might promote their phagocytic uptake, leading to the release of parasite ligands and the IFN-I response in N67 infection. In contrast, an elevated inflammatory response mediated by CD14/TLR and p38 signaling played a role in disease severity and early host death in N67C-infected mice. In addition to identifying cytosolic DNA/RNA sensors and signaling pathways previously unrecognized in malaria infection, our study demonstrates the importance of parasite genetic backgrounds in malaria pathology and provides important information for studying human malaria pathogenesis.
Strain-specific innate immune signaling pathways determine malaria parasitemia dynamics and host mortality.
Sex, Specimen part
View SamplesMost individuals with cystic fibrosis (CF) carry one or two mutations that result in a maturation defect of the full-length CFTR protein. The deltaF508 mutation results in a mutant protein that is degraded by the proteasome instead of progressing to the apical membrane where it functions as a cyclic AMP-regulated chloride channel. 4 phenylbutyrate modulates heat shock protein expression and promotes trafficking of deltaF508 thus permitting maturation and membrane insertion. The goal of this study was to gain insight into the genetic mechanism of PBA action through a large-scale analysis of gene expression. The Affymetrix genome spanning U133 microarray set was used to compare mRNA expression in untreated IB3-1 cell line cultures with cultures treated with 1mM 4-phenylbuyterate for 12 and 24 hr. IB3-1 deltaF508/W1282X) bronchial epithelial cells were cultured in T75 flasks with gentamicin-free LHC-8 medium. Cells were fed with 10 ml of media every 2 to 3 days. After reaching 80% confluence cells were treated with 1 mM PBA. A T75 flask of confluent IB3-1 cells was rinsed twice with ice cold Hanks buffer then scraped into 3ml of ice cold TRIzol (Gibco BRL) then rinsed with 3 ml ice cold TRIzol and the mRNA was isolated according to the TRIzol protocol. A total of 5 control cultures, 3 cultures with 12 hr BPA application and 3 cultures with 24 hr PBA application were processed
Gene expression profile analysis of 4-phenylbutyrate treatment of IB3-1 bronchial epithelial cell line demonstrates a major influence on heat-shock proteins.
No sample metadata fields
View SamplesThroughout Metazoa, developmental processes are controlled by a surprisingly limited number of conserved signaling pathways. Precisely how these signaling cassettes were assembled in early animal evolution remains poorly understood, as do the molecular transitions that potentiated the acquisition of their myriad developmental functions. Here we analyze the molecular evolution of the proto-oncogene YAP/Yorkie, a key effector of the Hippo signaling pathway that controls organ size in both Drosophila and mammals. Based on heterologous functional analysis of evolutionarily distant Yap/Yorkie orthologs, we demonstrate that a structurally distinct interaction interface between Yap/Yorkie and its partner TEAD/Scalloped became fixed in the eumetazoan common ancestor. We then combine transcriptional profiling of tissues expressing phylogenetically diverse forms of Yap/Yorkie with ChIP-seq validation in order to identify a common downstream gene expression program underlying the control of tissue growth in Drosophila. Intriguingly, a subset of the newly-identified Yorkie target genes are also induced by Yap in mammalian tissues, thus revealing a conserved Yap-dependent gene expression signature likely to mediate organ size control throughout bilaterian animals. Combined, these experiments provide new mechanistic insights while revealing the ancient evolutionary history of Hippo signaling. We sought to define the downstream target genes of selected Yap variants by performing RNA sequencing analysis (RNA-seq) on total RNA isolated from GMR-Gal4>Yap eye discs. Overall design: Transcriptional profiles were generated in triplicate from eye imaginal disks with either endogenous Yki, or GMR-Gal4 over-expressed Yki, Trichoplax Yap, Monosiga Yap, or Monisiga Yap+TEAD domain, using deep sequencing via Illumina Hi Seq.
Molecular evolution of the Yap/Yorkie proto-oncogene and elucidation of its core transcriptional program.
Treatment, Subject
View SamplesSummary: CF patients homozygous for the DF08 DF08 genotype present a full range of phenotypic manifestations that exist within the pulmonary system. This project aims to identify candidate genes that influence the severity of pulmonary disease
Respiratory epithelial gene expression in patients with mild and severe cystic fibrosis lung disease.
No sample metadata fields
View SamplesCystic Fibrosis lung disease progresses by a combination of accelerated airways inflammation and bacterial colonization and infection. Airways inflammation in CF is predominantly neutrophilic and complicates airway clearance therapies through cellular debris, excessive DNA, excessive and viscous mucous, and high concentrations of neutrophils,Il-8 and related cytokines liberated along the NFkB signaling pathway. We conducted a single site, randomized, double blind, placebo-controlled, proof-of-concept trial in which we evaluated the effects of 28 days of two dose levels (0.05 mg and 0.10 mg daily) of an older cardiac glycoside, digitoxin, as compared with placebo, on inflammatory markers in induced sputum obtained from 24 subjects with mild to moderate CF lung disease. Nasal epithelial cells from 23 subjects were analyzed for microarray analysis. CF patients 18 to 45 years old, any genotype combination, were eligible.
Digitoxin for Airway Inflammation in Cystic Fibrosis: Preliminary Assessment of Safety, Pharmacokinetics, and Dose Finding.
Specimen part, Disease, Disease stage, Treatment, Subject, Time
View SamplesRegulation of gene expression is integral to the development and survival of all organisms. Transcription begins with the assembly of a pre-initiation complex at the gene promoter, followed by initiation of RNA synthesis and the transition to productive elongation. In many cases, recruitment of RNA polymerase II (Pol II) to a promoter is necessary and sufficient for activation of gene. However, there are a few notable exceptions to this paradigm, including heat shock genes and several proto-oncogenes, whose expression is attenuated by regulated stalling of polymerase elongation within the promoter-proximal region. To determine the importance of polymerase stalling for transcription regulation, we performed a genome-wide search for Drosophila genes with promoter-proximally stalled Pol II. Our data reveal that stalling is widespread, occurring at hundreds of genes that respond to stimuli and developmental signals, indicating a role for regulation of polymerase elongation in the transcriptional responses to dynamic environmental and developmental cues.
RNA polymerase is poised for activation across the genome.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
VEGF-B signaling impairs endothelial glucose transcytosis by decreasing membrane cholesterol content.
Age, Specimen part, Cell line, Treatment
View SamplesRegulation of endothelial nutrient transport is poorly understood. Vascular endothelial growth factor (VEGF)-B signaling in endothelial cells promotes uptake and transcytosis of fatty acids (FA) from the bloodstream to the underlying tissue, advancing pathological lipid accumulation and lipotoxicity in diabetic complications. Here we demonstrate a VEGF-B dependent obstruction of endothelial glucose transport attributed to plasma membrane lipid alterations affecting glucose transporter 1 function, which was independent of FA uptake. Specifically, VEGF-B signaling impaired recycling of low-density lipoprotein receptor to the plasma membrane, leading to reduced cholesterol uptake and membrane cholesterol loading, decreasing endothelial glucose uptake capacity. Inhibiting VEGF-B in vivo was accordingly linked to reconstitution of membrane cholesterol and induction of glucose uptake, of particular relevance for conditions inferring insulin resistance and diabetic complications. In summary, our study reveals a novel mechanism of action for VEGF-B in endothelial nutrient uptake and highlights the impact of membrane cholesterol for the regulation of endothelial glucose transport.
VEGF-B signaling impairs endothelial glucose transcytosis by decreasing membrane cholesterol content.
Specimen part, Cell line, Treatment
View SamplesRegulation of endothelial nutrient transport is poorly understood. Vascular endothelial growth factor (VEGF)-B signaling in endothelial cells promotes uptake and transcytosis of fatty acids (FA) from the bloodstream to the underlying tissue, advancing pathological lipid accumulation and lipotoxicity in diabetic complications. Here we demonstrate a VEGF-B dependent obstruction of endothelial glucose transport attributed to plasma membrane lipid alterations affecting glucose transporter 1 function, which was independent of FA uptake. Specifically, VEGF-B signaling impaired recycling of low-density lipoprotein receptor to the plasma membrane, leading to reduced cholesterol uptake and membrane cholesterol loading, decreasing endothelial glucose uptake capacity. Inhibiting VEGF-B in vivo was accordingly linked to reconstitution of membrane cholesterol and induction of glucose uptake, of particular relevance for conditions inferring insulin resistance and diabetic complications. In summary, our study reveals a novel mechanism of action for VEGF-B in endothelial nutrient uptake and highlights the impact of membrane cholesterol for the regulation of endothelial glucose transport.
VEGF-B signaling impairs endothelial glucose transcytosis by decreasing membrane cholesterol content.
Age, Specimen part
View Samples