The growth of neural stem cells is strongly enhanced on myelin in vitro and in vivo. To identify the mechanisms associated with this phenome, we compared RNA expression from mouse E12 derived spinal cord cells on stimulation substrates (laminin and myelin) to permissive substrates (PDL). We identified Negr1 as mediator of the stimulatory effects of myelin. Overall design: Examination of transcripts in embryonic spinal cord cells stimulated by laminin and myelin substrates in vitro.
Adult rat myelin enhances axonal outgrowth from neural stem cells.
Specimen part, Subject
View SamplesWe sought to determine the genes regulated by the Drosophila Hox protein AbdA in a homogenous cell system. S2-DRSC cells that have no Hox expression were stably transfected with HA-tagged AbdA under the control of a metallothionein promoter. Overall design: S2-DRSC cells are stably transfected with HA-tagged AbdA (S2-DRSC:AbdA). S2 and S2-AbdA cells are analysed for gene expression in the absence (S2-DRSC) and presence (S2-DRSC-HA::AbdA) of AbdA
Human ZKSCAN3 and Drosophila M1BP are functionally homologous transcription factors in autophagy regulation.
Cell line, Treatment, Subject
View SamplesPatients with metastatic colorectal cancer were enrolled for treatment with cetuximab monotherapy. Transcriptional profiling was conducted on RNA from pre-treatment metastatic site biopsies to identify genes whose expression correlates with best clinical responses.
Expression of epiregulin and amphiregulin and K-ras mutation status predict disease control in metastatic colorectal cancer patients treated with cetuximab.
Specimen part
View SamplesDamage to and/or loss of sensory neurons can result in debilitating neuropathies that often have a dramatic impact on quality of life. The cellular mechanisms involved in the response of neurons and glia to such pathological insults are poorly understood. Investigation has shown that peripheral glia play critical roles in both the degenerative and regenerative processes that are involved in the responses to peripheral nerve damage. The vast majority of studies have focused primarily on myelinating Schwann cells], with the result that very little is known regarding how the non-myelinating glia that ensheath axons and neuronal somas respond to nerve damage. This is a significant knowledge gap, given that over 80% of cutaneous fibers are unmyelinated, that they transduce such important modalities as itch, pain, temperature, touch and pressure, and that they are affected in many prevalent peripheral neuropathies. It is the goal of this study to shed light on the genetic programs involved in the responses of non-myelinating glia roles to nerve degeneration. We utilized RNA-seq to identify genes that were differentially expressed in the larval head during the process of sensory neuron ablation and axon degeneration in both wild-type larvae and in larvae that do not have peripheral glia (foxd3 mutants) using a selective, conditional approach. Overall, the information regarding differential gene expression in these conditions will provide a basis for further investigation into the cellular processes that underlie pathophysiological responses of neurons and glia to sensory nerve damage. Overall design: mRNA levels were determined using biological triplicate samples from five sets of samples. Three sets from wild-type: control, 2 hrs of metronidazole treatment and 5 hrs of metronidazole treatment. And two sets from foxd3 mutants: control and 5hrs of metronidazole treatment.
Transcriptome Analysis of Chemically-Induced Sensory Neuron Ablation in Zebrafish.
No sample metadata fields
View SamplesTienilic acid (TA) was withdrawn from the US market due to numerous cases of liver necrosis. Two major hypotheses currently used to understand the mechanisms of idiosyncratic reactions such as TA-induced hepatotoxicity are the hapten and danger hypotheses. Both human cytochrome (CYP) P450 2C9 and the rat ortholog CYP 2C11 metabolize TA, and it was reported that a reactive metabolite of TA binds almost exclusively to these enzymes, thus acting as a mechanism-based inhibitor. TA-induced liver toxicity is associated with antibodies against CYP 2C9, thus TA appears to act as a hapten. However, if the binding were limited to CYP 2C, it is unlikely that this would lead to significant cell stress. Thus, if TA does not cause cell stress it would suggest that a drug does not have to generate a danger signal in order to cause an idiosyncratic drug reaction and acting as a hapten is sufficient. In order to test whether TA can cause cell stress, male Sprague Dawley rats were orally dosed with TA, and hepatic gene expression was profiled at 6 and 24 h after drug administration.
Changes in gene expression induced by tienilic Acid and sulfamethoxazole: testing the danger hypothesis.
No sample metadata fields
View SamplesExpression analysis of 36 pancreatic ductal adenocarcinoma tumors and matching normal pancreatic tissue samples from pancreatic cancer patients of the Clinical Institute Fundeni (ICF) using Affymetrix U133 Plus 2.0 whole-genome chips.
Combined gene expression analysis of whole-tissue and microdissected pancreatic ductal adenocarcinoma identifies genes specifically overexpressed in tumor epithelia.
Subject
View SamplesAlzheimer's disease (AD) is a devastating neurodegenerative disorder that threatens to reach epidemic proportions as our population ages. Although much research has examined molecular pathways associated with AD, relatively few studies have focused on critical early stages. Our prior microarray study correlated gene expression in human hippocampus with AD markers. Results suggested a new model of early-stage AD in which pathology spreads along myelinated axons, orchestrated by upregulated transcription and epigenetic factors related to growth and tumor suppression (Blalock et al., 2004). However, the microarray analyses were performed on RNA from fresh frozen hippocampal tissue blocks containing both gray and white matter, potentially obscuring region-specific changes. In the present study, we used laser capture microdissection to exclude major white matter tracts and selectively collect CA1 hippocampal gray matter from formalin-fixed, paraffin-embedded (FFPE) hippoc ampal sections of the same subjects assessed in our prior study. Microarray analyses of this gray matter-enriched tissue revealed many correlations similar to those seen in our prior study, particularly for neuron-related genes. Nonetheless, in the laser-captured tissue, we found a striking paucity of the AD-associated epigenetic and transcription factor genes that had been strongly overrepresented in the prior tissue block study. In addition, we identified novel pathway alterations that may have considerable mechanistic implications, including downregulation of genes stabilizing ryanodine receptor Ca2+ release and upregulation of vascular development genes. We conclude that FFPE tissue can be a reliable resource for microarray studies, that upregulation of growth-related epigenetic/ transcription factors with incipient AD is predominantly localized to white matter, further supporting our prior findings and model, and that alterations in vascular and ryanodine receptor-relat ed pathways in gray matter are closely associated with incipient AD.
Microarray analyses of laser-captured hippocampus reveal distinct gray and white matter signatures associated with incipient Alzheimer's disease.
Sex, Age, Disease
View SamplesMacrophages play a critical role in the pathogenesis of many diseases, including rheumatoid arthritis, inflammatory bowel disease and atherosclerosis. Monocytes recruited into tissues from peripheral blood differentiate into macrophages. There is limited data concerning the global changes in the expression of genes during monocyte to macrophage, and how the patterns of change identify the mechanism contributing to differentiation or macrophage function. Employing the microarray technology, we examined the transcriptional profile of in vitro adherence-induced differentiation of primary human monocytes into macrophages. We found the significant up regulation of genes contributing to the functions of macrophage, including signature patterns defining the induction of genes contributing to immunity and defense; lipid, fatty acid and steroid metabolism; cell adhesion and; carbohydrate metabolism; amino acid metabolism and endocytosis. In contrast, a variety of transcription factors were down regulated during monocyte to macrophage differentiation, suggesting that transcriptional repression may be important for the transition from monocytes to macrophages. However, a limited number of transcription factors were up regulated, among these was C/EBPA, which may contribute to differentiation by regulating down stream genes, which a characteristic of differentiated macrophages. These observations suggest that examination of the transcriptional profile in monocytes and macrophages in patients may identify relevant therapeutic targets in diseases such as rheumatoid arthritis and atherosclerosis.
Transcriptional diversity during monocyte to macrophage differentiation.
No sample metadata fields
View SamplesALTERED MERISTEM PROGRAM1 (AMP1) is a member of the M28 family of carboxypeptidases with a pivotal role in cell fate maintenance in the embryo and shoot meristem. A defect in AMP1 function results in suspensor to embryo conversion and a hypertrophic shoot meristem forming ectopic stem cell pools. However, so far the role of AMP1 in shoot development could not be assigned to a specific molecular pathway nor is its biochemical function resolved. Double mutants in CYP78A5 and CYP78A7 develop a similar set of cell fate defects. To further assess whether this phenotypic overlap is also depicted in a congruency at the global gene expression level, we analyzed the transcriptomic responses of both genotypes
AMP1 and CYP78A5/7 act through a common pathway to govern cell fate maintenance in Arabidopsis thaliana.
Age, Specimen part
View SamplesClassically activated (M1) macrophages protect from infection but can cause inflammatory disease and tissue damage while alternatively activated (M2) macrophages reduce inflammation and promote tissue repair. Modulation of macrophage phenotype may be therapeutically beneficial and requires further understanding of the molecular programs that control macrophage differentiation. A potential mechanism by which macrophages differentiate may be through microRNA (miRNA), which bind to messenger RNA and post-transcriptionally modify gene expression, cell phenotype and function. The inflammation-associated miRNA, miR-155, was rapidly up-regulated over 100-fold in M1, but not M2, macrophages. Inflammatory M1 genes and proteins iNOS, IL-1b and TNF-a were reduced up to 72% in miR-155 knockout mouse macrophages, but miR-155 deficiency did not affect expression of genes associated with M2 macrophages (e.g., Arginase-1). Additionally, a miR-155 oligonucleotide inhibitor efficiently suppressed iNOS and TNF-a gene expression in wild-type M1 macrophages. Comparative transcriptional profiling of unactivated (M0) and M1 macrophages derived from wild-type and miR-155 knockout (KO) mice revealed an M1 signature of approximately 1300 genes, half of which were dependent on miR-155. Real-Time PCR of independent datasets validated miR-155's contribution to induction of iNOS, IL-1b, TNF-a, IL-6 and IL-12, as well as suppression of miR-155 targets Inpp5d, Tspan14, Ptprj and Mafb. Overall, these data indicate that miR-155 plays an essential role in driving the differentiation and effector potential of inflammatory M1 macrophages.
Control of the Inflammatory Macrophage Transcriptional Signature by miR-155.
Specimen part, Treatment
View Samples