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GSE81023
Gallus gallus
6 Downloadable Samples
Affymetrix Chicken Genome Array (chicken)
Description
Cranial placodes contribute to all sense organs and sensory ganglia in the vertebrate head. Despite their diversity they originate from a common pool of Six1/Eya2+ progenitors. In a molecular screen we identify new factors upstream of the Six1/Eya2 cassette and use these to dissect the transcriptional hierarchy that controls progenitor specification. We find that although two different tissues, the lateral head mesoderm and the prechordal mesendoderm, induce placode progenitors, both initiate a common transcriptional state, but over time gradually impart regional character.
Publication Title
Cell interactions, signals and transcriptional hierarchy governing placode progenitor induction.
Sample Metadata Fields
Specimen part
View Samples- Rattus norvegicus
- 8 Downloadable Samples
- Affymetrix Rat Genome 230 2.0 Array (rat2302)
Description
GLUCOCORTICOIDS are steroid hormones that strongly influence intermediary carbohydrate metabolism by increasing the transcription rate of glucose-6-phosphatase (G6Pase) a key enzyme of gluconeogenesis, and suppress the immune system which makes them one of the most important therapeutic agents in the treatment of allergic, autoimmune and inflammatory diseases. The biologic actions of circulating glucocorticoids are transmitted to the cells nucleus by the glucocorticoid receptor (GR). The nuclear liver X receptors (LXRs) bind to cholesterol metabolites, heterodimerize with the retinoid X receptor (RXR), and regulate the cholesterol turnover, the hepatic glucose metabolism by decreasing the expression of G6Pase, and repress a set of inflammatory genes in immune cells. The aim of this study is to evaluate the crosstalk between the GR- and LXR-mediated signaling systems. Transient transfection-based reporter assays and gene silencing methods using siRNAs for LXRs showed that overexpression/ligand (GW3965) activation of LXRs/RXRs repressed GR-stimulated transactivation of certain glucocorticoid response element (GRE)-driven promoters in a gene-specific fashion. Activation of LXRs by GW3965 attenuated dexamethasone-stimulated elevation of circulating glucose in rats and suppressed dexamethasone-induced mRNA expression of hepatic glucose-6-phosphatase (G6Pase) in rats, mice and human hepatoma HepG2 cells. In microarray transcriptomic analysis of rat liver, GW3965 differentially regulated glucocorticoid-induced transcriptional activity of about 15% of endogenous glucocorticoid-responsive genes. Mechanistically, and in vitro chromatin immunoprecipitation assay, we found that LXR/RXR bound GREs and inhibited GR binding to these DNA sequences in a gene-specific fashion. These novel results were further confirmed in in vivo binding assays, and in gel mobility shift assays, where recombinant LXR/RXR proteins were used to examine their interaction with classic or G6Pase GREs. We propose that administration of LXR agonists may be beneficial in glucocorticoid treatment- or stress-associated dysmetabolic states by directly attenuating the transcriptional activity of the GR on glucose and/or lipid metabolism.
Publication Title
Liver x receptors regulate the transcriptional activity of the glucocorticoid receptor: implications for the carbohydrate metabolism.
Sample Metadata Fields
Specimen part
View Samples- Rattus norvegicus
- 8 Downloadable Samples
- Affymetrix Rat Genome 230 2.0 Array (rat2302)
Description
Glucocorticoids play central roles in the regulation of energy metabolism by shifting it toward catabolism, while AMPK is the master regulator of energy homeostasis, sensing energy depletion and stimulating pathways of increasing fuel uptake and saving on peripheral supplies. We showed here that AMPK regulates glucocorticoid actions on carbohydrate metabolism by targeting the glucocorticoid receptor (GR) and modifying transcription of glucocorticoid-responsive genes in a tissue- and promoter-specific fashion. Activation of AMPK in rats reversed glucocorticoid-induced hepatic steatosis and suppressed glucocorticoid-mediated stimulation of glucose metabolism. Transcriptomic analysis in the liver suggested marked overlaps between the AMPK and glucocorticoid signaling pathways directed mostly from AMPK to glucocorticoid actions. AMPK accomplishes this by phosphorylating serine 211 of the human GR indirectly through phosphorylation and consequent activation of p38 MAPK and by altering attraction of transcriptional coregulators to DNA-bound GR. In human peripheral mononuclear cells, AMPK mRNA expression positively correlated with that of glucocorticoid-responsive GILZ, which correlated also positively with the body mass index of subjects. These results indicate that the AMPK-mediated energy control system modulates glucocorticoid action at target tissues. Since increased action of glucocorticoids is associated with development of metabolic disorders, activation of AMPK could be a promising target for developing pharmacologic interventions to these pathologies.
Publication Title
AMPK regulates metabolic actions of glucocorticoids by phosphorylating the glucocorticoid receptor through p38 MAPK.
Sample Metadata Fields
Sex
View Samples- Pseudomonas aeruginosa pao1, Pseudomonas aeruginosa
- 10 Downloadable Samples
- Affymetrix Pseudomonas aeruginosa Array (paeg1a)
Description
In the present in vitro study, interactions between P. aeruginosa (sessile biofilms as well as planktonic cells) and PMNs were analyzed by means of DNA microarray based transcriptomics. We found that the P. aeruginosa wild type biofilms, in contrast to planktonic cultures and quorum sensing (QS) deficient strains, respond to PMN exposure in a rather aggressive manner. The response does not involve protective mechanisms such as those involved in oxidative stress. Rather it is dominated by QS controlled virulence determinants such as those encoded by pqs, phz, rhlAB, all of which are designed to cripple Eukaryotic cells including PMNs and macrophages. Our comparative analysis supports the view that QS plays a major role in mechanisms by which P. aeruginosa evades host defense systems.
Publication Title
Pseudomonas aeruginosa recognizes and responds aggressively to the presence of polymorphonuclear leukocytes.
Sample Metadata Fields
No sample metadata fields
View Samples- Gallus gallus
- 10 Downloadable Samples
- Affymetrix Chicken Genome Array (chicken)
Description
Few families of signaling factors have been implicated in the control of development. Here we identify the neuropeptides nociceptin and somatostatin, a neurotransmitter and neuroendocrine hormone, as a class of developmental signals in chick and zebrafish. We show that signals from the anterior mesendoderm are required for the formation of anterior placode progenitors with one of the signals being somatostatin. Somatostatin controls ectodermal expression of nociceptin and both peptides regulate Pax6 in lens and olfactory progenitors. Consequently, loss of somatostatin and nociceptin signaling leads to severe reduction of lens formation. Our findings not only uncover these neuropeptides as developmental signals, but also identify a long-sought-after mechanism that initiates Pax6 in placode progenitors and may explain the ancient evolutionary origin of neuropeptides, pre-dating a complex nervous system.
Publication Title
Neuropeptides: developmental signals in placode progenitor formation.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 3 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
Case story. A patient with massive infiltration of the visceral adipose tissue depot by BAT in a patient with a catecholamine secreting paraganglioma. BAT tissue was identified by protein expression of UCP1 (western blotting and immunostaining)
Publication Title
Chronic adrenergic stimulation induces brown adipose tissue differentiation in visceral adipose tissue.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 3 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
Hematopoietic stem cells (HSCs) primarily reside in the bone marrow where signals generated by stromal cells regulate their self-renewal, proliferation, and trafficking. Endosteal osteoblasts and perivascular stromal cells including endothelial cells3, CXCL12-abundant reticular (CAR) cells, leptin-receptor positive stromal cells, and nestin-GFP positive mesenchymal progenitors have all been implicated in HSC maintenance. However, it is unclear if specific hematopoietic progenitor cell (HPC) subsets reside in distinct niches defined by the surrounding stromal cells and the regulatory molecules they produce. CXCL12 (stromal-derived factor-1, SDF-1) regulates both HSCs and lymphoid progenitors and is expressed by all of these stromal cell populations.
Publication Title
CXCL12 in early mesenchymal progenitors is required for haematopoietic stem-cell maintenance.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 14 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
G-CSF regulates hematopoietic stem cell activity, in part, through activation of Toll-like receptor signaling.
Sample Metadata Fields
Specimen part, Treatment
View Samples- Mus musculus
- 8 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
Recent studies demonstrate that inflammatory signals regulate hematopoietic stem cells (HSCs). Granulocyte-colony stimulating factor (G-CSF) is often induced with infection and plays a key role in the stress granulopoiesis response. However, its effects on HSCs are less clear. Herein, we show that treatment with G-CSF induces expansion and increased quiescence of phenotypic HSCs, but causes a marked, cell-autonomous HSC repopulating defect associated with induction of toll-like receptor (TLR) expression and signaling. The G-CSF-mediated expansion of HSCs is reduced in mice lacking TLR2, TLR4 or the TLR signaling adaptor MyD88. Induction of HSC quiescence is abrogated in mice lacking MyD88 or in mice treated with antibiotics to suppress intestinal flora. Finally, loss of TLR4 or germ free conditions mitigates the G-CSF-mediated HSC repopulating defect. These data suggest that low level TLR agonist production by commensal flora contributes to the regulation of HSC function and that G-CSF negatively regulates HSCs, in part, by enhancing TLR signaling.
Publication Title
G-CSF regulates hematopoietic stem cell activity, in part, through activation of Toll-like receptor signaling.
Sample Metadata Fields
Specimen part, Treatment
View Samples- Mus musculus
- 6 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
Recent studies demonstratethat inflammatory signals regulate hematopoietic stem cells (HSCs). Granulocyte-colony stimulating factor (G-CSF) is often induced with infection and plays a key role in the stress granulopoiesis response. However, its effects on HSCs are less clear. Herein, we show that treatment with G-CSF induces expansion and increased quiescence of phenotypic HSCs, but causes a marked, cell-autonomous HSC repopulating defect associated with induction of toll-like receptor (TLR) expression and signaling. The G-CSF-mediated expansion of HSCs is reduced in mice lacking TLR2, TLR4 or the TLR signaling adaptor MyD88. Induction of HSC quiescence is abrogated in mice lacking MyD88 or in mice treated with antibiotics to suppress intestinal flora. Finally, loss of TLR4 or germ free conditions mitigates the G-CSF-mediated HSC repopulating defect. These data suggest that low level TLR agonist production by commensal flora contributes to the regulation of HSC function and that G-CSF negatively regulates HSCs, in part, by enhancing TLR signaling.
Publication Title
G-CSF regulates hematopoietic stem cell activity, in part, through activation of Toll-like receptor signaling.
Sample Metadata Fields
Specimen part, Treatment
View Samples