The eukaryotic cytoplasmic chaperonin-containing TCP-1 (CCT) is a complex formed by two back-to-back stacked hetero-octameric rings that assists the folding of actins, tubulins and other proteins in an ATP-dependent manner. Here, we decided to test the significance of the hetero-oligomeric nature of CCT for its function by introducing, in each of the eight subunits in turn, an identical mutation at a position involved in ATP binding and conserved in all the subunits, in order to establish the extent of individuality of the various subunits. Our results show that these identical mutations lead to dramatically different phenotypes. For example, cells with the mutation in CCT2 have an excess of actin patches and are the only pseudo-diploid strain. By contrast, cells with the mutation in CCT7 are the only ones to accumulate juxta-nuclear protein aggregates that may reflect the absence of stress response in this strain. System-level analysis of the strains using RNA microarrays reveals connections between CCT and several cellular networks including ribosome biogenesis and TOR2 that help to explain the phenotypic variability observed
Equivalent mutations in the eight subunits of the chaperonin CCT produce dramatically different cellular and gene expression phenotypes.
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View SamplesThe expression of adipogenic genes is decreased in obesity and diabetes mellitus
The expression of adipogenic genes is decreased in obesity and diabetes mellitus.
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View SamplesAccurate and reproducible quantitation of target genes depends on correct normalization. Historically, genes with variable tissue transcription e.g. GAPDH, have been used as normalization factors which is problematic, particularly in clinical samples which often are derived from different tissue sources. Using a large-scale gene database (GeneChip (Affymetrix U133A) dataset of 36 gastrointestinal tumors and normal tissues), we identified 8 candidate reference genes that were highly expressed with low variability and established expression levels by real-time RT-PCR in an independent set of GI tissue samples (n=42).
GeneChip, geNorm, and gastrointestinal tumors: novel reference genes for real-time PCR.
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View SamplesObesity is a strong risk factor for the development of type 2 diabetes. We have previously reported that in adipose tissue of obese (ob/ob) mice, the expression of adipogenic genes is decreased. When made genetically obese, the BTBR mouse strain is diabetes susceptible and the C57BL/6J (B6) strain is diabetes resistant. We used DNA microarrays and RT-PCR to compare the gene expression in BTBR-ob/ob versus B6-ob/ob mice in adipose tissue, liver, skeletal muscle, and pancreatic islets. Our results show: 1) there is an increased expression of genes involved in inflammation in adipose tissue of diabetic mice; 2) lipogenic gene expression was lower in adipose tissue of diabetes-susceptible mice, and it continued to decrease with the development of diabetes, compared with diabetes-resistant obese mice; 3) hepatic expression of lipogenic enzymes was increased and the hepatic triglyceride content was greatly elevated in diabetes-resistant obese mice; 4) hepatic expression of gluconeogenic genes was suppressed at the prediabetic stage but not at the onset of diabetes; and 5) genes normally not expressed in skeletal muscle and pancreatic islets were expressed in these tissues in the diabetic mice. We propose that increased hepatic lipogenic capacity protects the B6-ob/ob mice from the development of type 2 diabetes. Diabetes 52:688700, 2003
Gene expression profiles of nondiabetic and diabetic obese mice suggest a role of hepatic lipogenic capacity in diabetes susceptibility.
Sex, Age
View SamplesIgE antibodies mediate the symptoms of allergic reactions, yet these antibodies and the cells that produce them remain enigmatic due to their scarcity in humans. To address this, we have isolated single B cells of all isotypes, including rare IgE producing B cells, from the peripheral blood of food allergic individuals. Using single cell RNA sequencing (scRNA-seq) we have characterized the gene expression, splicing, and heavy and light chain antibody sequences of these cells.
High-affinity allergen-specific human antibodies cloned from single IgE B cell transcriptomes.
Sex, Age, Specimen part, Disease
View SamplesTranscriptome analysis of Casz1 was performed using litters of postnatal day 2 retinas from crosses between Casz1Flox/Flox; R26-Stop-EYFP and Casz1Flox/Flox; IKCre-A; R26-Stop-EYFP. The IK-A Cre driver is described in Tarchini et al., Dev Dyn 241(12):1973-85. EYFP marks Cre expressing (and therefore cKO) cells. Cells were incubated for 30 min in RGM serum-free medium described in Cayouette et al., Neuron 40(5):897, supplemented with Hoechst 33342 (Invitrogen), and 4N cells were sorted using a MOFLO cytometer (Beckman) based on Hoechst, GFP expression, and propidium iodide exclusion. Overall design: Cells were sorted directly into lysis buffer on ice and RNA was immediately extracted using RNeasy mini columns (Qiagen). Two independent experiments were performed, and the RNA samples were processed in parallel. RNA amplification was performed using Truseq PE Cluster kit v3 PE50 (Illumina). Deep sequencing was performed using Truseq stranded mRNA (Illumina) with mRNA enrichment and strand-specific parameters, using a Hiseq 2000 instrument (Illumina).
Casz1 controls higher-order nuclear organization in rod photoreceptors.
Specimen part, Cell line, Subject
View SamplesGLUCOCORTICOIDS are steroid hormones that strongly influence intermediary carbohydrate metabolism by increasing the transcription rate of glucose-6-phosphatase (G6Pase) a key enzyme of gluconeogenesis, and suppress the immune system which makes them one of the most important therapeutic agents in the treatment of allergic, autoimmune and inflammatory diseases. The biologic actions of circulating glucocorticoids are transmitted to the cells nucleus by the glucocorticoid receptor (GR). The nuclear liver X receptors (LXRs) bind to cholesterol metabolites, heterodimerize with the retinoid X receptor (RXR), and regulate the cholesterol turnover, the hepatic glucose metabolism by decreasing the expression of G6Pase, and repress a set of inflammatory genes in immune cells. The aim of this study is to evaluate the crosstalk between the GR- and LXR-mediated signaling systems. Transient transfection-based reporter assays and gene silencing methods using siRNAs for LXRs showed that overexpression/ligand (GW3965) activation of LXRs/RXRs repressed GR-stimulated transactivation of certain glucocorticoid response element (GRE)-driven promoters in a gene-specific fashion. Activation of LXRs by GW3965 attenuated dexamethasone-stimulated elevation of circulating glucose in rats and suppressed dexamethasone-induced mRNA expression of hepatic glucose-6-phosphatase (G6Pase) in rats, mice and human hepatoma HepG2 cells. In microarray transcriptomic analysis of rat liver, GW3965 differentially regulated glucocorticoid-induced transcriptional activity of about 15% of endogenous glucocorticoid-responsive genes. Mechanistically, and in vitro chromatin immunoprecipitation assay, we found that LXR/RXR bound GREs and inhibited GR binding to these DNA sequences in a gene-specific fashion. These novel results were further confirmed in in vivo binding assays, and in gel mobility shift assays, where recombinant LXR/RXR proteins were used to examine their interaction with classic or G6Pase GREs. We propose that administration of LXR agonists may be beneficial in glucocorticoid treatment- or stress-associated dysmetabolic states by directly attenuating the transcriptional activity of the GR on glucose and/or lipid metabolism.
Liver x receptors regulate the transcriptional activity of the glucocorticoid receptor: implications for the carbohydrate metabolism.
Specimen part
View SamplesAnalysis of rice leaves (V2 stage) in response to a short treatment with very high CO2 concentration in the dark, using standard atmosphere as control.
High CO2 concentration as an inductor agent to drive production of recombinant phytotoxic antimicrobial peptides in plant biofactories.
Specimen part, Treatment
View SamplesThere are currently no biological tests that differentiate patients with bipolar disorder (BPD) from healthy controls. While there is evidence that peripheral gene expression differences between patients and controls can be utilized as biomarkers for psychiatric illness, it is unclear whether current use or residual effects of antipsychotic and mood stabilizer medication drives much of the differential transcription. We therefore tested whether expression changes in first-episode, never-medicated bipolar patients, can contribute to a biological classifier that is less influenced by medication and could potentially form a practicable biomarker assay for BPD.
Utilization of never-medicated bipolar disorder patients towards development and validation of a peripheral biomarker profile.
Sex, Age, Specimen part
View SamplesComparatative gene expression analysis for CD4 T cell subsets isolated from peripheral blood and palatine tonsils
A methodology for global validation of microarray experiments.
Specimen part
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