The use of tubulin binders (TBs) in oncology indications often is associated with cardiotoxicity, the mechanism of which has not been elucidated. We observed that a single administration of TBs to rats caused an increase in the number of mitotic figures in the myocardial interstitium after 24 hours. We therefore hypothesized that interstitial cells are the primary target of TBs. To test this hypothesis, we evaluated the acute effects of a single intravenous administration of 3 reference TBs, colchicine (0.2 and 2 mg/kg), vinblastine (0.5 and 3 mg/kg), and vincristine (0.1 and 1 mg/kg) 6 and 24 hours after dosing. Mitotic arrest was identified at 24 hours in all high-dose groups based on an increase in the number of mitotic figures in the interstitium coupled with a dramatic decrease in the number of Ki67-positive interstitial cells. Analysis of the myocardial transcriptomic data further supported G2/M cell cycle arrest 6 hours after dosing with the high-dose groups of all 3 compounds. Apoptotic figures and an increase in the number of cleaved caspase 3-positive cells were identified at 6 and 24 hours at the highest dose of each compound almost exclusively in interstitial cells; a few cardiomyocytes were affected as well. Transcriptomic data further suggested that some of the affected interstitial cells were endothelial cells based on the up-regulation of genes typically associated with vascular damage and down-regulation of Endothelial Cell-Specific Molecule 1 and Apelin. Taken together, these data identify endothelial cells of the myocardium as the primary target of the cardiotoxicity of TBs and identify cell cycle arrest as the mechanism of this toxicity.
No associated publication
Sex, Specimen part, Treatment
View SamplesGene expression was evaluated in the myocardium of male Wistar rats after a single sc administration of 0.5 mg of isoproterenol, a -adrenergic agonist that causes acute tachycardia with subsequent myocardial necrosis. Histology of the heart, clinical chemistry and hematology were evaluated at 9 time-points (0.5 hr to 14 d post-injection). Myocardial gene expression was evaluated at 4 time-points (1 hr to 3 d). Contraction bands and loss of cross striation were identified on phosphotungstic acid-hematoxylin-stained sections 0.5 hr post-dosing. Plasma troponin I elevation was detected at 0.5 hr, peaked at 3 hr, and returned to baseline values at 3 d post-dosing. Interleukin 6 (Il6) expression spiked at 1-3 hr and was followed by a short-lived time-dependant dysregulation of its downstream targets. Concurrently and consistent with the kinetics of the histologic findings, many pathways indicative of necrosis/apoptosis (p38 MAPK signaling, NF-kB signaling) and adaptation to hypertension (PPAR signaling) were over-represented at 3 hr. The 1 d and 3 d time-points indicated an adaptative response, with down-regulation of the fatty acid metabolism pathway, up-regulation of the fetal gene program, and superimposed inflammation and repair at 3 d. These results suggest early involvement of Il6 in isoproterenol-induced myocardial necrosis and emphasize the value of early time-points in transcriptomic studies
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View SamplesPlasmacytoid dendritic cells (pDCs) can be activated by the endosomal TLRs, and contribute to the pathogenesis of systemic lupus erythematosus (SLE) by producing type I IFNs. Thus, blocking TLR-mediated pDC activation may represent a useful approach for the treatment of SLE. In an attempt to identify a therapeutic target for blocking TLR signaling in pDCs, we investigated the contribution of Bruton's tyrosine kinase (Btk) to the activation of pDCs by TLR7 and TLR9 stimulation by using a selective Btk inhibitor RN486. Stimulation of TLR7 and 9 with their respective agonist, namely, gardiquimod and type A CpG ODN2216, resulted in the activation of human pDCs, as demonstrated by the expression of activation markers (CD69, CD40, and CD86), elevated production of IFN-alpha and other inflammatory cytokines, as well as up-regulation of numerous genes including IFN-alpha-inducible genes and activation of interferon regulatory factor 7 (IRF7) and NF-kB. RN486 inhibited all of these events induced by TLR9, but not TLR7 stimulation, with a nanomolar potency for inhibiting type A CpG ODN2216-mediated production of cytokines (e.g., IC50=386 nM for inhibiting IFN-alpha). Our data reveal Btk as an important regulatory enzyme in the TLR9 pathway, and a potential therapeutic target for SLE and other TLR-driven diseases.
No associated publication
Specimen part, Treatment, Subject, Time
View SamplesStore operated calcium entry (SOCE) downstream of T cell receptor (TCR) activation in T lymphocytes has been shown to be mediated mainly through the Calcium Release Activated Calcium (CRAC) channel. Here, we compared the effects of a novel, potent and selective CRAC inhibitor, 2,6-Difluoro-N-{5-[4-methyl-1-(5-methyl-thiazol-2-yl)-1,2,5,6-tetrahydro-pyridin-3-yl]-pyrazin-2-yl}-benzamide (RO2959), on T cell effector functions with that of a previously reported CRAC channel inhibitor, YM-58483, and a calcineurin inhibitor Cyclosporin A (CsA). Using both electrophysiological and calcium-based fluorescence measurements, we showed that RO2959 is a potent SOCE inhibitor that blocked an IP3-dependent current in CRAC-expressing RBL-2H3 cells and CHO cells stably expressing human Orai1 and Stim1, as well as SOCE in human primary CD4+ T cells triggered by either TCR stimulation or thapsigargin treatment. Furthermore, we demonstrated that RO2959 completely inhibited cytokine production as well as T cell proliferation mediated by TCR stimulation or MLR (Mixed Lymphocyte Reaction). Lastly, we showed by gene expression array analysis that RO2959 potently blocked TCR triggered gene expression and T cell functional pathways similar to CsA and FK506. Thus, both from a functional and transcriptional level, our data provide evidence that RO2959 is a novel and selective CRAC inhibitor that potently inhibits human T cell functions.
Characterization of a novel CRAC inhibitor that potently blocks human T cell activation and effector functions.
Specimen part, Treatment, Subject
View SamplesThe gene expression profile of blood drawn from healthy individuals was studied over a period of six months, at five time points. The gene expression profiles appeared to be constant over one month and to slightly vary over three months. A small proportion of genes were found to be differentially regulated according to gender. Differential gene regulation by age (in subjects 2555 years of age versus subjects > 55 years of age) was not observed.
A longitudinal study of gene expression in healthy individuals.
Sex, Age, Specimen part, Subject
View SamplesA total of 40 female mice 129/SV aged 3-6 months and weighting 18-25 g were used (Janvier, Le Genest-St-Isle, France). NTS was injected in mice (10 l/gBW/day) during three consecutive days. The total number of mice was divided to five treatment groups as followed: 8 mice were injected with PBS and fed with vehicle, 8 mice were injected with NTS and fed with vehicle, 8 mice were injected with NTS and fed with low dose DDR1i, 8 mice were injected with NTS and fed with high dose DDR1i and 8 mice were injected with NTS and fed with Imatinib. All treatments were provided by oral gavage. Treatment was started one day [PM{1}] prior first injection of NTS or PBS. The average food intake was controlled by weighing the food every three days. Mice were found to consume about 4g/day/mouse [PM{2}] which was similar to all groups.
No associated publication
Sex, Specimen part, Treatment
View SamplesGene expression analysis followed by gene onthology pathway analysis revealed that cell cycle and growth and proliferation pathways were significantly affected in the high dose group at the 24h time point.
No associated publication
Specimen part
View SamplesAnalysis of human iPS-derived cardiomyocytes exposed to glucose, endothelin-1 and cortisol in vitro. Treatment produces a surrogate diabetic cardiomyopathic phenotype. Results provide insight into the pathways regulated by the treatment in the cardiomyocyte.
Disease modeling and phenotypic drug screening for diabetic cardiomyopathy using human induced pluripotent stem cells.
Specimen part, Treatment, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Oncogenic pathway combinations predict clinical prognosis in gastric cancer.
Specimen part, Cell line
View SamplesGenome-wide mRNA expression profiles of 200 primary gastric tumors from the Singapore patient cohort. Gastric cancer (GC) is the second leading cause of global cancer mortality, with individual gastric tumors displaying significant heterogeneity in their deregulation of various oncogenic pathways. We aim to identify major oncogenic pathways in GC that robustly impact patient survival and treatment response. We used an in silico strategy based on gene expression signatures and connectivity analytics to map patterns of oncogenic pathway activation in 25 unique GC cell lines, and in 301 primary gastric cancers from three independent patient cohorts. Of 11 oncogenic pathways previously implicated in GC, we identified three predominant pathways (proliferation/stem cell, NF-kB, and Wnt/b-catenin) deregulated in the majority (>70%) of gastric tumors. Using a variety of proliferative, Wnt, and NF-kB-related assays, we experimentally validated the pathway predictions in multiple GC cell lines showing similar pathway activation patterns in vitro. Patients stratified at the level of individual pathways did not exhibit consistent differences in clinical outcome. However, patients grouped by oncogenic pathway combinations demonstrated robust and significant survival differences (e.g., high proliferation/high NF-kB vs. low proliferation/low NF-kB), suggesting that tumor behavior in GC is likely influenced by the combined effects of multiple oncogenic pathways. Our results demonstrate that GCs can be successfully taxonomized by oncogenic pathway activity into biologically and clinically relevant subgroups.
Oncogenic pathway combinations predict clinical prognosis in gastric cancer.
Specimen part
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