The tryptophan degrading enzyme TDO2 is downregulated upon HIF1alpha stabilization by exposure to both hypoxia as well as chemical hypoxia mimetics such as DMOG in glioblastoma cell line A172.
Hypoxia Inducible Factor 1α Inhibits the Expression of Immunosuppressive Tryptophan-2,3-Dioxygenase in Glioblastoma.
Cell line
View SamplesEngineering of genetically encoded calcium indicators predominantly focused on optimizing fluorescence changes, but effects of indicator expression on host organisms have largely not been addressed. Here, we report biocompatibility and wide-spread functional expression of the genetically encoded calcium indicator TN-XXL in a transgenic mouse model. To validate the model and to characterize potential effects of indicator expression we assessed both indicator function and a variety of host parameters such as anatomy, physiology, behavior and gene expression profiles in these mice. We also demonstrate the usefulness of primary cell types and organ explants prepared from these mice for imaging applications. While we do find mild signatures of indicator expression that may guide further indicator development the green indicator mice generated provide a well characterized resource of primary cells and tissues for in vitro and in vivo calcium imaging applications.
Biocompatibility of a genetically encoded calcium indicator in a transgenic mouse model.
Specimen part
View SamplesTo analyze the impact of photosynthetic redox signals, light sources with spectral qualities that preferentially excite either Photosystem I (PSI light) or Photosystem II (PSII light) were used. The light sources have been described in (Wagner et al, Planta 2008). Strong reduction signals were induced by light shifts from PSI to PSII light (PSI-II). In order to find primary regulated genes the acclimation responses were monitored at 30 min and 60 min after a light shift. The control was continuous Psi light at the same time. We used stn7 (a thylakoid redox regulated kinase) to specifically block transduction of photosynthetic redox signal in order to compare real redox regulated with that of other light acclimation pathways.
Identification of Early Nuclear Target Genes of Plastidial Redox Signals that Trigger the Long-Term Response of Arabidopsis to Light Quality Shifts.
Specimen part, Treatment, Time
View SamplesActivating Transcription Factor 4 (ATF4) is a transcription factor induced by the integrated stress response (ISR). This experiment is a genome-wide profiling of ATF4-dependent RNA expression in human HAP-1 cells. HAP-1 is a near-haploid human cell line that was derived from KBM-7 cells isolated from a patient with Chronic Myelogenous Leukemia. We analyzed WT and ATF4 KO cells. We induced ATF4 expression by mimicking amino acid starvation with the drug histidinol. Overall design: RNA expression profiles were generated for WT and ATF4 KO HAP1 cells. ATF4 genes were mutated using Cas9 genome editing technology. Amino acid starvation was mimicked by treating WT and ATF4 KO cells with 2 mM histidinol for 24 hours, which increases ATF4 expression.
A forward genetic screen reveals novel independent regulators of ULBP1, an activating ligand for natural killer cells.
No sample metadata fields
View SamplesHeLa cells were treated with siRNA directed against Luciferase or RENT1 in duplicate (as described in Mendell et al., Science, 2002; PubMed ID:12228722). Transcripts that are differentially expressed between the two experimental conditions are putatively regulated by RENT1.
Nonsense surveillance regulates expression of diverse classes of mammalian transcripts and mutes genomic noise.
No sample metadata fields
View SamplesDiffuse large B-cell lymphoma (DLBCL) represents a heterogeneous diagnostic category with distinct molecular subtypes that can be defined by gene expression profiling. However, even within these defined subtypes, heterogeneity prevails. To further elucidate the pathogenesis of these entities, we determined the expression of the tumor suppressor phosphatase and tensin homolog (PTEN) in 248 primary DLBCL patient samples. These analyses revealed that loss of PTEN was detectable in 55% of germinal center B-cell-like (GCB) DLBCLs, whereas this abnormality was found in only 14% of non-GCB DLBCL patient samples. In GCB DLBCL, the PTEN status was inversely correlated with activation of the oncogenic PI3K/ protein kinase B (AKT) pathway in both DLBCL cell lines and primary patient samples. Re-expression of PTEN induced cytotoxicity in PTEN-deficient GCB DLBCL cell line models by inhibiting PI3K/AKT signaling, indicating an addiction to this pathway in this subset of GCB DLBCLs. PI3K/AKT inhibition induced down-regulation of the transcription factor MYC. Re-expression of MYC rescued GCB DLBCL cells from PTEN-induced toxicity, identifying a regulatory mechanism of MYC expression in DLBCL. Finally, pharmacologic PI3K inhibition resulted in toxicity selectively in PTEN-deficient GCB DLBCL lines. Collectively, our results indicate that PTEN loss defines a PI3K/ AKT-dependent GCB DLBCL subtype that is addicted to PI3K and MYC signaling and suggest that pharmacologic inhibition of PI3K might represent a promising therapeutic approach in these lymphomas.
PTEN loss defines a PI3K/AKT pathway-dependent germinal center subtype of diffuse large B-cell lymphoma.
Sex, Disease, Cell line, Treatment
View SamplesNatalizumab is a recombinant monoclonal antibody raised against integrin alpha-4 (CD49d). It is approved for the treatment of patients with multiple sclerosis (MS), a chronic inflammatory autoimmune disease of the CNS. Natalizumab blocks leukocyte extravasation across the blood-brain barrier by inhibiting the molecular interaction between integrin alpha-4/beta-1 heterodimers expressed on leukocytes and VCAM-1 on inflammatory-activated CNS endothelium. Here we investigated whether binding of this adhesion-blocking antibody to T lymphocytes modulated their phenotype by direct induction of intracellular signaling events. Natalizumab induced a mild upregulation of IL-2, IFN-gamma and IL-17 expression in activated primary human CD4+ T cells propagated ex vivo from healthy donors, consistent with a pro-inflammatory costimulatory effect on lymphokine expression. Overall, the relative effect of natalizumab was more pronounced in less than in fully activated T cells. Along with this, natalizumab binding triggered rapid MAPK/ERK phosphorylation. Furthermore, it decreased CD49d surface expression on effector cells within a few hours. Sustained CD49d downregulation could be attributed to integrin internalization and degradation. Importantly, also CD4+ T cells from some MS patients receiving their very first dose of natalizumab produced more IL-2, IFN-gamma and IL-17 already 24 h after infusion. Together these data indicate that in addition to its adhesion-blocking mode of action, natalizumab possesses mild direct signaling capacities, which may support a pro-inflammatory phenotype of peripheral blood T lymphocytes. This might explain why a rebound of disease activity is observed in some MS patients after natalizumab cessation.
Natalizumab exerts direct signaling capacity and supports a pro-inflammatory phenotype in some patients with multiple sclerosis.
Specimen part, Disease, Disease stage, Treatment
View SamplesILLUMINATE (Investigation of Lipid Level Management to Understand its Impact in Atherosclerotic Events), the phase 3 morbidity and mortality trial of torcetrapib, a cholesteryl ester transfer protein (CETP) inhibitor, identified previously undescribed changes in plasma levels of potassium, sodium, bicarbonate, and aldosterone. A key question after this trial is whether the failure of torcetrapib was a result of CETP inhibition or of some other pharmacology of the molecule. The direct effects of torcetrapib and related molecules on adrenal steroid production were assessed in cell culture using the H295R as well as the newly developed HAC15 human adrenal carcinoma cell lines. Torcetrapib induced the synthesis of both aldosterone and cortisol in these two in vitro cell systems. Analysis of steroidogenic gene expression indicated that torcetrapib significantly induced the expression of CYP11B2 and CYP11B1, two enzymes in the last step of aldosterone and cortisol biosynthesis pathway, respectively. Transcription profiling indicated that torcetrapib and angiotensin II share overlapping pathways in regulating adrenal steroid biosynthesis. Hormone-induced steroid production is mainly mediated by two messengers, calcium and cAMP. An increase of intracellular calcium was observed after torcetrapib treatment, whereas cAMP was unchanged. Consistent with intracellular calcium being the key mediator of torcetrapibs effect in adrenal cells, calcium channel blockers completely blocked torcetrapib-induced corticoid release and calcium increase. A series of compounds structurally related to torcetrapib as well as structurally distinct compounds were profiled. The results indicate that the pressor and adrenal effects observed with torcetrapib and related molecules are independent of CETP inhibition.
Torcetrapib induces aldosterone and cortisol production by an intracellular calcium-mediated mechanism independently of cholesteryl ester transfer protein inhibition.
Specimen part, Cell line, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
IκB-ζ controls the constitutive NF-κB target gene network and survival of ABC DLBCL.
Cell line, Treatment
View SamplesConstitutive activation of the nuclear factor-kappa B (NF-kB) pathway is a hallmark of the activated B-cell-like (ABC) subtype of diffuse large B-cell lymphoma (DLBCL). Recurrent mutations of NF-kB regulators that cause constitutive activity of this oncogenic pathway have been identified. However, it remains unclear how specific target genes are regulated. We identified the IkB-like protein NFKBIZ that binds NF-kB subunits and enhances transactivation of some NF-kB target genes while repressing others, to be upregulated in ACB compared to GCB DLBCL primary patient samples (p=5.1 x 10^-37). Knockdown of NFKBIZ by RNA interference was toxic to ABC but not GCB DLBCL cell lines. Gene expression profiling following NFKBIZ knockdown significantly downregulated a large number of NF-kB target genes, suggesting a central role in regulating NF-kB signaling. To further investigate the molecular mechanisms of how NFKBIZ mediates NF-kB signaling in ABC DLBCL, we performed immunoprecipitations and detected an interaction of NFKBIZ with both p50 and p52 NF-kB subunits, indicating that both the canonical and non-canonical NF-kB pathways are regulated by NFKBIZ. Collectively, our data imply that NFKBIZ is required for NF-kB signaling in ABC DLBCL and thus might represent a promising molecular target for future therapies.
IκB-ζ controls the constitutive NF-κB target gene network and survival of ABC DLBCL.
Cell line
View Samples