Secretion of insulin by pancreatic cells in response to glucose is central for glucose homeostasis, and dysregulation of this process is a hallmark of the early stages of diabetes. We utilized a tetracycline-inducible approach to investigate the immediate impact of a pulse of Sox17 expression on the insulin secretory pathway. Sox17 gain-of-function animals (Sox17-GOF) were generated using an Ins2-rtTA mouse line and a line in which Sox17 expression is regulated by the tetracycline transactivator (tetO-Sox17). Administering doxycycline to 16-week old mice resulted in Sox17 overexpression in mature cells in the islets.
Sox17 regulates insulin secretion in the normal and pathologic mouse β cell.
Age, Specimen part
View SamplesIn order to address the progression, metastasis, and clinical heterogeneity of renal cell cancer (RCC), transcriptional profiling with oligonucleotide microarrays (22,283 genes) was done on 49 RCC tumors, 20 non-RCC renal tumors, and 23 normal kidney samples. Samples were clustered based on gene expression profiles and specific gene sets for each renal tumor type were identified. Gene expression was correlated to disease progression and a metastasis gene signature was derived. Gene signatures were identified for each tumor type with 100% accuracy. Differentially expressed genes during early tumor formation and tumor progression to metastatic RCC were found. Subsets of these genes code for secreted proteins and membrane receptors and are both potential therapeutic or diagnostic targets. A gene pattern ("metastatic signature") derived from primary tumors was very accurate in classifying tumors with and without metastases at the time of surgery. A previously described "global" metastatic signature derived by another group from various non-RCC tumors was validated in RCC. Unlike previous studies, we describe highly accurate and externally validated gene signatures for RCC subtypes and other renal tumors. Interestingly, the gene expression of primary tumors provides us information about the metastatic status in the respective patients and has the potential, if prospectively validated, to enrich the armamentarium of diagnostic tests in RCC. We validated in RCC, for the first time, a previously described metastatic signature and further showed the feasibility of applying a gene signature across different microarray platforms. Transcriptional profiling allows a better appreciation of the molecular and clinical heterogeneity in RCC.
Gene signatures of progression and metastasis in renal cell cancer.
Specimen part
View SamplesWe discovered a rare missense mutation in NR1H4 (R436H), which encodes the farnesoid X receptor (FXR), associating with lower levels of total cholesterol in the Icelandic population. To explore the effects of R436H we used CRISPR-Cas9 to generate homozygous NR1H4 R436H and NR1H4 knockout human iPSC lines which we differentiated to hepatocytes. Hepatocytes were treated with an FXR agonist for 24 hours and transcript abundance measured by RNA-seq. The global response to FXR activation in NR1H4 R436H cells was very similar to that of wild-type cells showing that it is not a loss-of-function mutation. However, we did observe subtle gene expression differences compatible with an effect on lipids when we compared R436H agonist treated hepatocytes to wild-type agonist treated hepatocytes. Overall design: RNA-seq was performed on wild-type, NR1H4 knockout and NR1H4 R436H iPSC-derived hepatocytes treated with FXR agonist GW4064.
Predicted loss and gain of function mutations in ACO1 are associated with erythropoiesis.
Specimen part, Treatment, Subject
View SamplesBackground: Survival and function of insulin-secreting pancreatic -cells are markedly altered by changes in nutrient availability. In vitro, culture in 10 rather than 2mM glucose improves rodent -cell survival and function whereas glucose concentrations above 10mM are deleterious. Aim-Method: To identify the mechanisms of such -cell plasticity, we tested the effects of a 18h culture at 2, 5, 10 and 30mM glucose on the transcriptome of rat islets precultured for 1 week at 10mM glucose (Affymetrix Rat 230.2 arrays). Results: Culture in either 2-5mM or 30mM instead of 10mM glucose markedly impaired -cell function without affecting islet cell survival. Of ~16000 probe sets reliably detected in islets, ~5000 were significantly regulated at least 1.4-fold by glucose. Analysis of these probe sets with GeneCluster software identified 10 mRNA profiles with unidirectional up- or down-regulation between 2 and 10, 2 and 30, 5 and 10, 5 and 30 or 10 and 30 mM glucose, and 8 complex V-shaped or inverse V-shaped profiles with a nadir or peak level of expression in 5 or 10mM glucose. Analysis of genes belonging to these various clusters with Onto-express and GenMapp software revealed several signaling and metabolic pathways that may contribute to the induction of -cell dysfunction and apoptosis after culture in low or high vs. intermediate glucose concentration. Conclusion: We have identified 18 distinct mRNA profiles of glucose-induced changes in islet gene mRNA levels that should help understanding the mechanisms by which glucose affects -cell survival and function under states of chronic hypo- or hyperglycemia.
Cluster analysis of rat pancreatic islet gene mRNA levels after culture in low-, intermediate- and high-glucose concentrations.
No sample metadata fields
View SamplesConsumption of diets rich in fibers has been associated with several beneficial effects on gastrointestinal health. However, detailed studies on the molecular effects of fibers in colon are limited. In this study we investigated and compared the influence of five different fibers on the mucosal transcriptome, and luminal microbiota and SCFA concentrations in murine colon. Mice were fed diets enriched with fibers that differed in carbohydrate composition, namely inulin (IN), oligofructose (FOS), arabinoxylan (AX), guar gum (GG), resistant starch (RS) or a control diet (corn starch) for 10 days. Gene expression profiling revealed the regulation of specific, but also overlapping sets of epithelial genes by each fiber, which on a functional level were mainly linked to cell cycle and various metabolic pathways including fatty acid oxidation, tricarboxylic acid cycle, and electron transport chain. In addition, the transcription factor PPAR was predicted to be a prominent upstream regulator of these processes. Microbiota profiles were distinct per dietary fiber, but the fibers IN, FOS, AX and GG induced a common change in microbial groups. All dietary fibers, except resistant starch, increased SCFA concentrations but to a different extent. Multivariate data integration revealed strong correlations between the expression of genes involved in energy metabolism and the relative abundance of bacteria belonging to the group of Clostridium cluster XIVa, that are known butyrate producers. These findings illustrate the potential of multivariate data analysis to unravel simple relationships in complex systems.
Comparison of the effects of five dietary fibers on mucosal transcriptional profiles, and luminal microbiota composition and SCFA concentrations in murine colon.
Sex, Age, Specimen part
View SamplesTo identify biological processes as well as molecular markers for drip loss, the transcriptomes of logissimus dorsi from 6 sib pair of F2 animals
Expression profiling of muscle reveals transcripts differentially expressed in muscle that affect water-holding capacity of pork.
No sample metadata fields
View SamplesIn this study, we used correlation analysis of the expression profiles and drip loss to produce a list of functional candidate genes under the assumption that genes with strong correlation between their expression values and drip belong to pathways or networks relevant for the control of the trait.
Trait correlated expression combined with expression QTL analysis reveals biological pathways and candidate genes affecting water holding capacity of muscle.
No sample metadata fields
View SamplesUsing PAXgene tubes, peripheral blood samples were collected from seven patients >18 years with documented pdm(H1N1) influenza, bilateral chest infiltrates, and in need of ventilation support. Significant co-morbidity was exclusion criterion. Expression profiles were compared with 7 age matched controls. Using a false discovery rate < 5% and an absolute fold change > 2, 370 genes were differentially expressed in case and controls.
Excessive innate immune response and mutant D222G/N in severe A (H1N1) pandemic influenza.
Sex, Age, Specimen part, Subject
View SamplesWe found that in rodents, b-cell mass expansion during pregnancy and obesity is associated with changes in the expression of a group of islet microRNAs. We were able to reproduce in isolated pancreatic islets the decrease of miR-338-3p level observed in gestation and obesity by activating the G-protein coupled estrogen receptor GPR30 and the GLP1 receptor. Blockade of miR-338-3p in b-cells using specific anti-miR molecules mimicked gene expression changes occurring during b-cell mass expansion and resulted in increased proliferation and improved survival both in vitro and in vivo. These findings point to a major role for miR-338-3p in compensatory b-cell mass expansion occurring under different insulin resistance states.
MicroRNAs contribute to compensatory β cell expansion during pregnancy and obesity.
Sex, Specimen part, Cell line
View SamplesThe bird cherry-oat aphid (Rhopalosiphum padi L.) (Homoptera: Aphididae) is an important pest on cereals causing plant growth reduction but no specific leaf symptoms. Breeding of barley (Hordeum vulgare L.) for R. padi resistance shows that there are several resistance genes involved, reducing aphid growth. In an attempt to identify candidate sequences for resistance-related genes, we performed a microarray analysis of gene expression after two days of aphid infestation in two susceptible barley lines and two genotypes with partial resistance. One of the four lines is a descendant of two of the other genotypes. The analysis revealed large differences in gene induction between the four lines, indicating substantial variation in response even between closely related genotypes. Genes induced in the aphid-infested tissue were mainly related to defence, primary metabolism and signalling. Only twenty-four genes were induced in all lines, none of them related to oxidative stress or secondary metabolism. Few genes were down-regulated and none of those was common to all four lines. There were differences in aphid-induced gene regulation between resistant and susceptible lines, and results from control plants without aphids also revealed differences in constitutive gene expression between the two types of lines. Candidate sequences for both induced and constitutive resistance factors have been identified, among them a proteinase inhibitor, a Ser/Thr kinase and several thionins.
Microarray analysis of the interaction between the aphid Rhopalosiphum padi and host plants reveals both differences and similarities between susceptible and partially resistant barley lines.
No sample metadata fields
View Samples