Identification of the role of retinoic acid on the activation of the dHSCs
Vitamin A-Retinoic Acid Signaling Regulates Hematopoietic Stem Cell Dormancy.
Specimen part
View SamplesEwing sarcoma family of tumors (ESFT) are aggressive bone and soft tissue tumors of unknown cellular origin. Most ESFT express EWS-FLI1, a chimeric protein which functions as a growth-promoting oncogene in ESFT but is toxic to most normal cells. A major difficulty in understanding EWS-FLI1 function has been the lack of an adequate model in which to study EWS-FLI1-induced transformation. Although the cell of origin of ESFT remains elusive, both mesenchymal (MSC) and neural crest (NCSC) have been implicated. We recently developed the tools to generate NCSC from human embryonic stem cells (hNCSC). In the current study we used this model to test the hypothesis that neural crest-derived stem cells are the cells of origin of ESFT and to evaluate the consequences of EWS-FLI1 expression on human neural crest biology.
Modeling initiation of Ewing sarcoma in human neural crest cells.
Specimen part
View SamplesThe full complement of molecular pathways contributing to Parkinsons disease (PD) pathogenesis remains unknown. Here, to address this issue, we began by using a high-resolution variant of functional magnetic resonance imaging (fMRI) to pinpoint brainstem regions differentially affected by, and resistant to, the disease. Then, relying on the imaging information as a guide, we profiled gene expression levels of postmortem brain samples and used a factorial statistical model to identify a disease related decrease in the expression of the polyamine enzyme spermidine/spermine N1-acetyltransferase 1 (SAT1). Next, a series of studies were performed to confirm the pathogenic relevance of this finding. First, to test for a causal link between polyamines and -synuclein toxicity, we investigated a yeast model expressing -synuclein. Polyamines were found to enhance the toxicity of -synuclein, and an unbiased genome-wide screen for modifiers of -synuclein toxicity identified Tpo4, a member of a family of proteins responsible for polyamine transport. Second, to test for a causal link between SAT1 activity and PD histopathology we investigated a mouse model expressing -synuclein. DENSPM (N1, N11-diethylnorspermine), a polyamine analog that increases SAT1 activity, was found to reduce PD histopathology, while Berenil (diminazene aceturate), a pharmacological agent that reduces SAT1 activity, worsened the histopathology. Third, we genotyped PD patients and controls and isolated a rare but novel variant in the SAT1 gene, although the functional significance of this genetic variant was not identified. Taken together, the results suggest that the polyamine pathway contributes to PD pathogenesis.
Polyamine pathway contributes to the pathogenesis of Parkinson disease.
Sex, Age, Subject
View SamplesTranscriptome analysis may provide means to investigate the underlying genetic causes of shared and divergent phenotypes in different populations and help to identify potential targets of adaptive evolution. Applying RNA sequencing to whole male Drosophila melanogaster from the ancestral tropical African environment and a very recently colonized cold-temperate European environment at both standard laboratory conditions and following a cold shock, we seek to uncover the transcriptional basis of cold adaptation. In both the ancestral and the derived populations, the predominant characteristic of the cold shock response is the swift and massive upregulation of heat shock proteins and other chaperones. Although we find ~30% of the genome to be differentially expressed following a cold shock, only relatively few genes (n=26) are up- or down-regulated in a population-specific way. Intriguingly, 24 of these 26 genes show a greater degree of differential expression in the African population. Likewise, there is an excess of genes with particularly strong cold-induced changes in expression in Africa on a genome-wide scale. The analysis of the transcriptional cold shock response most prominently reveals an upregulation of components of a general stress response, which is conserved over many taxa and triggered by a plethora of stressors. Despite the overall response being fairly similar in both populations, there is a definite excess of genes with a strong cold-induced fold-change in Africa. This is consistent with a detrimental deregulation or an overshooting stress response. Thus, the canalization of European gene expression might be responsible for the increased cold tolerance of European flies. Overall design: mRNA profiles of whole Drosophila melanogaster adult males from a Africa (4 lines) and Europe (4 lines) during a 7h cold shock experiment. Samples include room temperature controls, 3.5h into the cold shock, 15 minutes after recovery and 90 minutes after recovery. 2 biological replicates each.
Canalization of gene expression is a major signature of regulatory cold adaptation in temperate Drosophila melanogaster.
Sex, Subject
View SamplesAdaptively evolved mutants of yeast on galactose were characterized by feremtation physiology and tools from systems biology.
Unravelling evolutionary strategies of yeast for improving galactose utilization through integrated systems level analysis.
Time
View SamplesNatural killer (NKT) T cells exhibit tissue distribution, surface phenotype, and functional responses that are strikingly different from those of conventional T cells. The transcription factor PLZF is responsible for most of these properties, as its ectopic expression in conventional T cells is sufficient to confer to them an NKT-like phenotype. The molecular program downstream of PLZF, however, is largely unexplored.
PLZF Controls the Expression of a Limited Number of Genes Essential for NKT Cell Function.
Sex, Specimen part
View SamplesWe have determined the consequences of ICN1 overexpression from retroviral vectors introduced into bone marrow cells.
Oncogenesis of T-ALL and nonmalignant consequences of overexpressing intracellular NOTCH1.
No sample metadata fields
View SamplesMicroarray comparisons of polysome loading in wild-type Arabidopsis and eif3h mutant
On the functions of the h subunit of eukaryotic initiation factor 3 in late stages of translation initiation.
No sample metadata fields
View SamplesMicroarray comparisons of transcript level in wild-type Arabidopsis and eif3h mutant plants.
On the functions of the h subunit of eukaryotic initiation factor 3 in late stages of translation initiation.
No sample metadata fields
View SamplesAsthma is caused by a combination of poorly understood genetic and environmental factors. We found multiple markers on chromosome 17q21 to be strongly and reproducibly associated with childhood onset asthma in family and case-referent panels with a combined P < 10-12. In independent replication studies the 17q21 locus showed strong association with diagnosis of childhood asthma in 2,320 subjects from a cohort of German children (P = 0.0003) and in 3,301 subjects from the British 1958 Birth Cohort (P = 0.0005). We systematically evaluated the relationships between markers of the 17q21 locus and transcript levels of genes in EBV-transformed lymphoblastoid cell lines from children in the asthma family panel used in our association study. The SNPs associated with childhood asthma were consistently and strongly associated (P <10-22) in cis with transcript levels of ORMDL3, a member of a gene family that encode transmembrane proteins anchored in the endoplasmic reticulum. The results indicate that genetic variants regulating ORMDL3 expression are determinants of susceptibility to childhood asthma.
Genetic variants regulating ORMDL3 expression contribute to the risk of childhood asthma.
Sex
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