We assessed the impact of glucose transporter Glut2 gene inactivation in adult mouse liver (LG2KO mice). This suppressed hepatic glucose uptake but not glucose output. In the fasted state, expression of carbohydrate responsive element-binding protein (ChREBP) and its glycolytic and lipogenic target genes was abnormally elevated. Feeding, energy expenditure, and insulin sensitivity were identical in LG2KO and control mice. Glucose tolerance was normal early after Glut2 inactivation but intolerance developed at later time. This was caused by progressive impairment of glucose-stimulated insulin secretion even though beta-cell mass and insulin content remained normal. Liver transcript profiling revealed a coordinate down-regulation of cholesterol biosynthesis genes in LG2KO mice. This was associated with reduced hepatic cholesterol in fasted mice and a 30 percent reduction in bile acid production. We showed that chronic bile acids or FXR agonist treatment of primary islets increases glucose-stimulated insulin secretion, an effect not seen in islets from fxr-/- mice. Collectively, our data show that glucose sensing by the liver controls beta-cell glucose competence, through a mechanism that likely depends on bile acid production and action on beta-cells.
Hepatic glucose sensing is required to preserve β cell glucose competence.
Specimen part
View SamplesWe individually examined the ability of human ARGFX, DPRX, LEUTX, and TPRX1 to regulate gene expression by ectopically expressing these proteins in fibroblasts. Overall design: Each gene along with an empty control vector were transfected individually to drive ectopic expression in human dermal fibroblasts, in triplicate.
Evolutionary origin and functional divergence of totipotent cell homeobox genes in eutherian mammals.
Specimen part, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Defective T Memory Cell Differentiation after Varicella Zoster Vaccination in Older Individuals.
Sex, Age, Specimen part
View SamplesTo identify host factors that influence the immunogenicity of the attenuated VZV pOka vaccine strain and the efficacy of VZV vaccination, we immunized 39 individuals aged 50 to 75 years, including 9 monozygotic twin pairs. We measured VZV-specific T cell frequencies by IFN-specific ELISpot, and VZV-specific antibody titers by ELISA. Whole gene expression arrays were performed on vaccinees before (n=28) and one (n=18) or three days (n=10) after vaccination. Cell-specific gene expression profiles were generated by deconvolution using previously described algorithms. Only very few neutrophil- and lymphocyte-related genes changed in expression from day 0 to 1. Significant changes for monocyte-related genes were found, but even here the number of probes with a significant change was low after adjusting for false discovery. When expression changes in monocyte-derived genes were analyzed for their correlation with T cell responses, we identified 493 probes corresponding to 479 genes that correlated with generation of VZV-specific effector T cells and 641 probes corresponding to 621 genes that correlated with the subsequent contraction phase with p<0.05. Interestingly, these two sets of genes were significantly overlapping, i.e., the same changes that were positively or negatively correlated with expansion inversely predicted contraction; their effects therefore cancelled out in determining net benefit in memory cell generation.
Defective T Memory Cell Differentiation after Varicella Zoster Vaccination in Older Individuals.
Sex, Age, Specimen part
View SamplesWhile blood transcriptional profiling has improved diagnosis and understanding of disease pathogenesis of adult tuberculosis (TB), no studies applying gene expression profiling of children with TB have been described so far. In this study, we have compared whole blood gene expression in childhood TB patients, as well as in healthy latently infected (LTBI) and uninfected (HC) children in a cohort of Warao Amerindians in the Delta Amacuro in Venezuela. We identified a 116-gene signature set by means of random forest analysis that showed an average prediction error of 11% for TB vs. LTBI and for TB vs. LTBI vs. HC in our dataset. Furthermore, a minimal set of only 9 genes showed a significant predictive value for all previously published adult studies using whole blood gene expression, with average prediction errors between 17% and 23%. Additionally, a minimal gene set of 42 genes with a comparable predictive value to the 116-gene set in both our dataset and the previously published literature cohorts for the comparsion of TB vs. LTBI vs. HC was identified. In order to identify a robust representative gene set that would hold stand among different ethnic populations, we selected ten genes that were highly discriminative between TB, LTBI and HC in all literature datasets as well as in our dataset. Functional annotation of these ten genes highlights a possible role for genes involved in calcium signaling and calcium metabolism as biomarkers for active TB. These ten genes were validated by quantitative real-time polymerase chain reaction in an additional cohort of 54 Warao Amerindian children with LTBI, HC and non-TB pneumonia. Decision tree analysis indicated that five of the ten genes were sufficient to diagnose 78% of the TB cases correctly with 100% specificity. We conclude that our data justify the further exploration of our signature set as biomarkers to diagnose childhood TB. Furthermore, as the identification of different biomarkers in ethnically distinct cohorts is apparent, it is important to cross-validate newly identified markers in all available cohorts.
A predictive signature gene set for discriminating active from latent tuberculosis in Warao Amerindian children.
Sex, Age
View SamplesLRF, which is encoded by the ZBTB7A gene and formerly known as POKEMON (POK erythroid myeloid ontogenic factor), was originally identified as a PLZF (promyelocytic leukemia zinc finger) homologue interacting with BCL6 (B-cell lymphoma 6). LRF is a transcription factor that is broadly expressed in hematopoietic lineage cells, but its expression is particularly high in erythroblasts and germinal center (GC) B-cells. The goal of this study is to assess the effect of LRF loss on the LT-HSC transcriptome. Nine days after injection of adult mice with polyinosinic polycytidylic acid (pIpc) to activate Cre, total RNAs were isolated from double-sorted LT-HSCs from LRF Flox/+ Mx1-Cre+ and LRF Flox/Flox Mx1-Cre+ mice and processed for microarray analysis.
LRF-mediated Dll4 repression in erythroblasts is necessary for hematopoietic stem cell maintenance.
Age, Specimen part, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
IFN priming is necessary but not sufficient to turn on a migratory dendritic cell program in lupus monocytes.
Specimen part, Disease, Disease stage, Treatment, Subject, Time
View SamplesWe screened SLE monocytes from 19 SLE patients and selected 4 that induced CD4+ T cell proliferation in vitro and 4 that did not. CFSE labeled CD4-T cells (105) were incubated with SLE monocytes (2 x 104). Cells were harvested at 6 hours for RNA extraction.
IFN priming is necessary but not sufficient to turn on a migratory dendritic cell program in lupus monocytes.
Specimen part, Disease, Disease stage, Treatment, Subject, Time
View SamplesTo explore the full extent of IFN-regulated transcriptional changes, we exposed monocytes from two healthy donors to recombinant type I IFN (IFN-2b) in vitro. RNA was extracted at different incubation times (1, 6, 24, 48 and 72 hrs) and the expression data was normalized to that of monocytes cultured with medium.
IFN priming is necessary but not sufficient to turn on a migratory dendritic cell program in lupus monocytes.
Specimen part, Disease, Disease stage, Treatment, Time
View SamplesTo directly compare the SLE monocyte transcriptional program with that of blood mDC precursors, we purified lineage HLA-DRhighCD11chigh mDCs and CD14+ monocytes from the blood of five healthy donors. Their gene expression profiles were then compared to those of blood SLE monocytes. An unsupervised clustering analysis of transcripts present in >20% of the samples classified healthy monocytes, SLE monocytes and healthy mDCs into three well defined groups. A supervised analysis was then performed to find genes: 1) differentially expressed in healthy mDCs compared to monocytes; 2) shared by healthy blood mDCs and SLE blood monocytes.
IFN priming is necessary but not sufficient to turn on a migratory dendritic cell program in lupus monocytes.
Specimen part, Disease, Disease stage, Subject
View Samples