This study was undertaken to test the hypothesis that short term exposure (4 hours) to physiologic hyperinsulinemia in normal, healthy subjects without a family history of diabetes would induce a low grade inflammatory response, independently of glycemic status. We performed euglycemic hyperinsulinemic (80 mU/m2/min) clamps in 12 healthy, insulin sensitive subjects with no family history of diabetes followed by biopsies of the vastus lateralis muscle taken basally and after 30 and 240 minutes of insulin infusion. Gene expression profiles were generated using Affymetrix HG-U133A arrays. No probe sets had significantly altered expression at 30 minutes of the insulin clamp, but 121 probe sets (117 upregulated and 4 downregulated) were significantly altered after 240 minutes. Hyperinsulinemia in normal, healthy human subjects increased the mRNAs for a number of inflammatory genes and transcription factors. Microarray and quantitative RT-PCR revealed the upregulation of chemokine, cc motif, ligand 2 (CCL2), CCL8, thrombomodulin (THBD), ras-related associated with diabetes (RRAD), metallothionein (MT), and serum/glucocorticoid regulated kinase (SGK), and downregulation of CITED2 (a CREB-binding protein-interacting transactivator), a known coactivator of PPAR-alpha. Interestingly, SGK and CITED2 are located at chromosome 6q23, where we previously detected strong linkage to hyperinsulinemia. A control saline infusion performed on 3 normal, healthy subjects without a family history of diabetes demonstrated that the genes altered following the euglycemic-hyperinsulinemic clamp were due to insulin and independent of biopsy removal. This study demonstrates that insulin acutely regulates the expression of genes involved in inflammation and transcription, and identifies several candidate genes/pathways for further investigation.
Effect of acute physiological hyperinsulinemia on gene expression in human skeletal muscle in vivo.
Sex, Race
View SamplesInappropriate activation of developmental pathways is a well-recognized tumor-promoting mechanism. Here we show that overexpression of the homeoprotein Six1, normally a developmentally restricted transcriptional regulator, increases Transforming Growth Factor-beta (TGF-beta) signaling in mammary carcinoma cells and induces an epithelial to mesenchymal transition (EMT) that is in part dependent on its ability to increase TGF-beta signaling. TGF-beta signaling and EMT have been implicated in metastatic dissemination of carcinoma. Using spontaneous and experimental metastasis mouse models, we demonstrate that Six1 overexpression promotes breast cancer metastasis. In addition, we show that, like its induction of EMT, Six1-induced experimental metastasis is dependent on its ability to activate TGF-beta signaling. Importantly, in human breast cancers Six1 significantly correlates with nuclear Smad3, and thus increased TGF-beta signaling. Further, breast cancer patients whose tumors overexpress Six1 have a shortened time to relapse and metastasis, and an overall decrease in survival. Finally, we show that the effects of Six1 on tumor progression likely extend beyond breast cancer, since its overexpression correlates with adverse outcomes in numerous other cancers, including brain, cervical, prostate, colon, kidney, and liver, amongst others. Our findings argue that Six1, acting through TGF-beta signaling and EMT, is a powerful and global promoter of cancer metastasis.
The Six1 homeoprotein induces human mammary carcinoma cells to undergo epithelial-mesenchymal transition and metastasis in mice through increasing TGF-beta signaling.
Cell line
View SamplesThe study aimed to resolve the mechanisms of protective actions of MMP-8 in oral tongue squamous cell carcinoma.
The interplay of matrix metalloproteinase-8, transforming growth factor-β1 and vascular endothelial growth factor-C cooperatively contributes to the aggressiveness of oral tongue squamous cell carcinoma.
No sample metadata fields
View SamplesThe composition of the matrix molecules is important in in vitro cell culture experiments of e.g. human cancer invasion and vessel formation. Currently, the mouse Engelbreth-Holm-Swarm (EHS) sarcoma -derived products, such as Matrigel, are the most commonly used tumor microenvironment mimicking (TMEM) matrices for experimental studies. However, since Matrigel is non-human in origin, its molecular composition does not accurately simulate human TMEM and we expect myogel to be more natural environment for human cancer cells. The environment may have crucial impact on cell behavior and gene expression.
A novel human leiomyoma tissue derived matrix for cell culture studies.
Cell line
View SamplesRight ventricular samples were serially acquired during surgical repair of ventricular septal defect. Expression profiling revealed three patterns of gene expression: (1) increased expression above control levels within one hour of cardioplegic arrest, with further amplification during early reperfusion; (2) increased expression limited to the reperfusion phase; and (3) reduced expression during reperfusion.
Early gene expression profiles during intraoperative myocardial ischemia-reperfusion in cardiac surgery.
No sample metadata fields
View SamplesNon-nutritive sweeteners like sucralose are consumed by billions of people. While animal and human studies have demonstrated a link between synthetic sweetener consumption and metabolic dysregulation, the mechanisms responsible remain unknown. Here we use a diet supplemented with sucralose to investigate the long-term effects of sweet/energy imbalance. In flies, chronic sweet/energy imbalance promoted hyperactivity, insomnia, glucose intolerance, enhanced sweet taste perception and a sustained increase in food and calories consumed, effects that are reversed upon sucralose removal. Mechanistically, this response was mapped to the ancient insulin, catecholamine, and NPF/NPY systems and the energy sensor AMPK, which together comprise a novel neuronal starvation response pathway. Interestingly, chronic sweet/energy imbalance promoted increased food intake in mammals as well, and this also occurs through an NPY-dependent mechanism. Together our data show that chronic consumption of a sweet/energy imbalanced diet triggers a conserved neuronal fasting response and increases the motivation to eat. Overall design: RNA-seq on Drosophila head samples fed control and sucralose diet
Sucralose Promotes Food Intake through NPY and a Neuronal Fasting Response.
Specimen part, Cell line, Subject
View SamplesThe project had 2 goals:
Pooling samples within microarray studies: a comparative analysis of rat liver transcription response to prototypical toxicants.
No sample metadata fields
View SamplesThe 6-hydroxydopamine (6OHDA) rat model of parkinsonism is among the first, and most commonly used, animal models of Parkinsons disease. It provides insight into the compensatory changes that occur in the brain after dopamine (DA) neuron degeneration. In order to better define the consequences of substantia nigra DA neuron loss on the neural and glial populations during and following nigrostriatal degeneration, tissue was collected and evaluated from the substantia nigra of 6OHDA or vehicle treated, or nave rats at 1, 2, 4, 6 & 16 weeks.
The longitudinal transcriptomic response of the substantia nigra to intrastriatal 6-hydroxydopamine reveals significant upregulation of regeneration-associated genes.
Sex, Specimen part
View SamplesThe restoration of catalytic activity to mutant enzymes by small molecules is well-established for in vitro systems. Here we show that the protein tyrosine kinase Src R388A mutant can be rescued in live cells using the small molecule imidazole. Cellular rescue of a v-Src homolog was rapid and reversible and conferred predicted oncogenic properties. Using chemical rescue in combination with mass spectrometry, six known Src kinase substrates were confirmed, and several new protein targets identified. Chemical rescue data suggests that c-Src is active under basal conditions. Rescue of R388A c-Src also allowed contributions of Src to the MAP kinase pathway to be clarified. This chemical rescue approach is likely to be of broad utility in cell signaling.
Chemical rescue of a mutant enzyme in living cells.
No sample metadata fields
View SamplesmRNA expression in the spinal cords of the G93A-SOD1 familial ALS transgenic mouse model was compared to that in nontransgenic (Normal mouse) and transgenic mice expressing wild-type (WT)SOD1. Gene Ontology (GO)analysis was used to characterize differences in expression between G93A-SOD1 mouse and nontransgenic mouse spinal cord. Changes in multiple GO categories were found. Many of these were associated with subsystems involving cell-cell communication and intracellular signal transduction. Expression profiles of mice expressing WT-SOD1 did not differ from nontransgenic mice. In contrast, protein profiling using proteomics technology indicated changes in mitochondrial protein expression in the G93A-SOD1 mouse spinal cord that were not found in the mRNA expression analysis.
Informatics-assisted protein profiling in a transgenic mouse model of amyotrophic lateral sclerosis.
Age
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