Spinocerebellar ataxia type 2 (SCA2) is a neurodegenerative disorder, which is caused by an unstable CAG-repeat expansion in the SCA2 gene, that encodes a polyglutamine tract (polyQ-tract) expansion in ataxin-2 protein (ATXN2). The RNA-binding protein ATXN2 interacts with the poly(A)-binding protein PABPC1, localizing to ribosomes at the rough endoplasmic reticulum or to polysomes. Under cell stress ATXN2 and PABPC1 show redistribution to stress granules where mRNAs are kept away from translation and from degradation. It is unknown whether ATXN2 associates preferentially with specific mRNAs or how it modulates their processing. Here, we investigated Atxn2 knock-out (Atxn2-/-) mouse liver, cerebellum and midbrain regarding their RNA profile, employing oligonucleotide microarrays for screening and RNA deep sequencing for validation. Modest ~1.4-fold upregulations were observed for the level of many mRNAs encoding ribosomal proteins and other translation pathway factors. Quantitative reverse transcriptase PCR and immunoblots in liver tissue confirmed these effects and demonstrated an inverse correlation also with PABPC1 mRNA and protein. ATXN2 deficiency also enhanced phosphorylation of the ribosomal protein S6, while impairing the global protein synthesis rate, suggesting a block between the enhanced translation drive and the impaired execution. Furthermore, ATXN2 overexpression and deficiency retarded cell cycle progression. ATXN2 mRNA levels showed a delayed phasic twofold increase under amino acid and serum starvation, similar to ATXN3, but different from motor neuron disease genes MAPT and SQSTM1. ATXN2 mRNA levels depended particularly on mTOR signalling. Altogether the data implicate ATXN2 in the adaptation of mRNA translation and cell growth to nutrient availability and stress.
Genetic ablation of ataxin-2 increases several global translation factors in their transcript abundance but decreases translation rate.
Age, Specimen part
View SamplesAnaplasma phagocytophilum infects a wide variety of host species and causes the diseases granulocytic anaplasmosis in humans, horses and dogs and tick-borne fever in ruminants. The objective of this research was to characterize differential gene expression in wild boar naturally infected with A. phagocytophilum by microarray hybridization using the GeneChip Porcine Genome Array
Gene expression profile suggests that pigs (Sus scrofa) are susceptible to Anaplasma phagocytophilum but control infection.
Specimen part, Disease, Disease stage
View SamplesHigh grade serous carcinoma (HGSC) arising from either the fallopian tube or ovary has a poor prognosis primarily due to its early dissemination throughout the abdominal cavity. Genomic and proteomic approaches have provided snapshots of the proteogenomics of ovarian cancer (OvCa)1,2, but a systematic examination of both the tumor and stromal compartments is critical to understanding OvCa metastasis. We developed a label-free proteomic workflow to analyze as few as 5,000 formalin-fixed, paraffin embedded cells microdissected from each compartment. The tumor proteome was comparatively stable during progression from in situ lesions to metastatic disease; however, the metastasis-associated stroma was characterized by a highly conserved proteomic signature, prominently including the methyltransferase nicotinamide N-methyltransferase (NNMT) and the proteins it regulates. Stromal NNMT expression was necessary and sufficient for several functional aspects of the cancer associated fibroblast (CAF) phenotype, including the expression of CAF markers and the secretion of cytokines and oncogenic extracellular matrix. Stromal NNMT supported OvCa migration, proliferation, and in vivo growth and metastasis. Expression of NNMT in CAFs led to a depletion of S-adenosyl methionine (SAM) and a reduction in histone methylation associated with extensive gene expression changes in the tumor stroma. This work supports the use of ultra-low input proteomics to identify candidate drivers of disease phenotypes and reveals that NNMT is a central, metabolic regulator of CAF differentiation and cancer progression in the stroma and a novel treatment target. Overall design: Three biological replicates of normal murine 3T3 fibroblasts expressing either control or NNMT overexpression construct were grown for 48 hours in physiological levels of methionine before RNA was collected and sequenced to identify genes differentially regulated in response to NNMT.
Proteomics reveals NNMT as a master metabolic regulator of cancer-associated fibroblasts.
Cell line, Subject
View SamplesNitrogen mustard (NM) is a vesicant known to target the lung, causing acute injury which progresses to fibrosis. Evidence suggests that activated macrophages contribute to the pathologic response to NM. In these studies, we analyzed the role of lung lipids generated following NM exposure on macrophage activation and phenotype. Treatment of rats with NM (0.125 mg/kg, i.t.) resulted in a time-related increase in enlarged vacuolated macrophages in the lung. At 28 d post exposure, macrophages stained positively for Oil Red O, a marker of neutral lipids. This was correlated with an accumulation of oxidized phospholipids in lung macrophages and epithelial cells, and an increase in bronchoalveolar lavage fluid (BAL) phospholipids. RNA-sequencing analysis revealed that lipid handling pathways under control of the transcription factors LXR, FXR and PPAR-? were significantly altered following NM exposure. Whereas at 1-3 d post NM, FXR and the downstream oxidized low density lipoprotein receptor, Cd36, were increased, Lxr and the lipid extrusion pump targets, Abca1 and Abcg1 were reduced. Treatment of naïve lung macrophages with lipid enriched fractions of BAL collected 3 d after NM resulted in upregulation of Nos2, Apoe and Ptgs2, markers of pro-inflammatory activation, while lipid-enriched BAL collected 28 d post NM upregulated expression of the anti-inflammatory markers, Il10, Cd163, and Cx3cr1, and induced the formation of lipid-laden foamy macrophages. These data suggest that NM-induced alterations in lipid handling and metabolism drive macrophage foam cell formation, potentially contributing to the development of pulmonary fibrosis. Overall design: Alveolar macrophages were collected by gentile message from male wistar rats 1 d or 28 d after intratracheal exposure to NM and from rats intratracheally exposed to PBS. There were three biological replicates per exposure group.
Regulation of Macrophage Foam Cell Formation During Nitrogen Mustard (NM)-Induced Pulmonary Fibrosis by Lung Lipids.
Sex, Specimen part, Cell line, Subject
View SamplesRNA prepared from specialized replum cells within siliques provided targets for profiling the Arabidopsis genome during replum cell development.
Laser capture microdissection of plant cells from tape-transferred paraffin sections promotes recovery of structurally intact RNA for global gene profiling.
Specimen part
View SamplesRett syndrome (RTT) is an X-linked dominant neurodevelopmental disorder caused by mutations in MECP2, encoding methyl-CpG binding protein 2. MeCP2 is a transcriptional repressor elevated in mature neurons and is predicted to be required for neuronal maturation by regulating multiple target genes. Identifying primary gene targets in either Mecp2-deficient mice or human RTT brain has proven to be difficult, perhaps because of the transient requirement for MeCP2 during neuronal maturation. In order to experimentally control the timing of MeCP2 expression and deficiency during neuronal maturation, human SH-SY5Y cells undergoing mature neuronal differentiation were transfected with methylated MeCP2 oligonucleotide decoy to disrupt the binding of MeCP2 to endogenous targets. Genome-wide expression microarray analysis identified all four known members of the inhibitors of differentiation or inhibitors of DNA binding (ID1, ID2, ID3 and ID4) subfamily of helix-loop-helix (HLH) genes as novel neuronal targets of MeCP2. Chromatin immunoprecipitation analysis confirmed binding of MeCP2 near or within the promoters of ID1, ID2 and ID3, and quantitative RT-PCR confirmed increased expression of all four Id genes in Mecp2-deficient mouse brain. All four ID proteins were significantly increased in Mecp2-deficient mouse and human RTT brain using immunofluorescence and laser scanning cytometric analyses. Because of their involvement in cell differentiation and neural development, ID genes are ideal primary targets for MeCP2 regulation of neuronal maturation that may explain the molecular pathogenesis of RTT.
Inhibitors of differentiation (ID1, ID2, ID3 and ID4) genes are neuronal targets of MeCP2 that are elevated in Rett syndrome.
No sample metadata fields
View SamplesWe have applied a new software to analyse a human naive single-chain antibody (scFv) library, comprehensively revealing the diversity of antibody variable complementarity-determining regions (CDRs) and their families.
A novel DNAseq program for enhanced analysis of Illumina GAII data: a case study on antibody complementarity-determining regions.
No sample metadata fields
View SamplesThe zinc finger transcription factor growth-factor-independent-1 (Gfi1) has been involved in various cellular differentiation processes. Gfi1 acts as a transcriptional repressor and splicing control factor upon binding to cognate binding sites in regulatory elements of its target genes. Here, we report that Gfi1-deficient mice develop autoimmunity. Gfi1-deficient peripheral B-cells show a hyperproliferative phenotype, leading to expansion of plasma cells, increased levels of nuclear autoantibodies, and immunoglobulin deposition in brain and kidneys. Dysregulation of multiple transcription factors and cell-cycle control elements may contribute to B-cell dependent autoimmunity. Gfi1 thus emerges as a novel master-regulator restricting autoimmunity.
Transcription factor Gfi1 restricts B cell-mediated autoimmunity.
Specimen part
View SamplesBackground: We hypothesize that important genomic differences between breast cancer subtypes occur early in carcinogenesis. Therefore, gene expression might distinguish histologically normal breast epithelium (NlEpi) from breasts containing estrogen receptor positive (ER+) compared with estrogen receptor negative (ER-) cancers.
Gene expression profiles of estrogen receptor-positive and estrogen receptor-negative breast cancers are detectable in histologically normal breast epithelium.
Specimen part, Disease, Disease stage
View SamplesThe liver is one of most important organs in our bodies. It performs many essential functions including metabolism, synthesis, secretion, detoxification, and storage. Hepatocytes are the principal cell type in the liver and are involved in multiple liver-specific functions. There have been several efforts to develop in vitro culture systems capable of maintaining hepatocyte-specific phenotype over long time periods. In hepatic tissue engineering, two commonly used culture systems are the collagen sandwich and monolayers of cells. In this study, genome-wide gene expression profiles of primary hepatocytes were measured over an 8-day period for each cell culture system using Affymetrix GeneChips and analyzed via Gene Set Enrichment Analysis (GSEA), which is a powerful method to elicit biologically meaningful information from microarray data at the level of gene sets. Results indicate that the gene expression in hepatocytes in collagen sandwich cultures gradually diverges from that in monolayer cultures. Gene sets up-regulated in collagen sandwich cultures include those associated with liver metabolic and synthetic functions. These functions are associated with lipid, amino acid, carbohydrate, and alcohol metabolism and bile acid synthesis. Nuclear receptors are up-regulated in collagen sandwiches 24 hours after seeding. Signals transmitted from these receptors may cause the up-regulation of other processes in subsequent days. Cytochrome-P450 monooxygenase expression was initially down-regulated but exhibited up-regulation after 72 hours. Our results provide a baseline for further explorations into the systems biology of engineered liver mimics as well as 2D and 3D co-cultures of primary hepatocytes and non-parenchymal cells.
A comparative study of genome-wide transcriptional profiles of primary hepatocytes in collagen sandwich and monolayer cultures.
Specimen part
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