Primordial germ cells (PGCs), the embryonic precursors of eggs and sperm, are a unique model for identifying and studying regulatory mechanisms in singly migrating cells. From their time of specification to eventual colonization of the gonad, mouse PGCs traverse through and interact with many different cell types, including epithelial cells and mesenchymal tissues. Work in drosophila and zebrafish have identified many genes and signaling pathways involved in PGC migration, but little is known about this process in mammals.
Discrete somatic niches coordinate proliferation and migration of primordial germ cells via Wnt signaling.
Specimen part
View SamplesMounting evidence points to a link between a cancer possessing stem-like properties and a worse prognosis. To understand the biology, a common approach is to integrate network biology with signal processing mechanics. That said, even with the right tools, predicting the risk for a highly susceptible target using only a handful of gene signatures remains very difficult. By compiling the expression profiles of a panel of tumor stem-like cells (TSLCs) originating in different tissues, comparing these to their parental tumor cells (PTCs) and the human embryonic stem cells (hESCs), and integrating network analysis with signaling mechanics, we propose that network topologically-weighted signaling processing measurements under tissue-specific conditions can provide scalable and predicable target identification.
Network biology of tumor stem-like cells identified a regulatory role of CBX5 in lung cancer.
Specimen part
View SamplesPostnatal handling in rodents leads to decreased anxiety-like behavior in adulthood. We used microarrays to look at gene expression differences in the CA1 region of the hippocampus in female mice subjected to postnatal handling compared to controls.
Variation in the large-scale organization of gene expression levels in the hippocampus relates to stable epigenetic variability in behavior.
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View SamplesGenetically identical inbred mice exhibit substantial stable individual variability in exploratory behavior. We used microarrays to look at gene expression differences in the hippocampus in female mice separated by stable differences in exploratory behavior
Variation in the large-scale organization of gene expression levels in the hippocampus relates to stable epigenetic variability in behavior.
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View SamplesCD24 is a potential oncogene reported to be overexpressed in a large variety of human malignancies. We have shown that CD24 is overexpressed in 90% of colorectal tumors at a fairly early stage in the multistep process of carcinogenesis. Anti-CD24 monoclonal antibodies (mAb) induce a significant growth inhibition in colorectal and pancreatic cancer cell lines that express the protein. This study is designed to investigate further the effects of CD24 down-regulation using mAb or small interfering RNA in vitro and in vivo. Western blot analysis showed that anti-CD24 mAb induced CD24 protein down-regulation through lysosomal degradation. mAb augmented growth inhibition in combination with five classic chemotherapies. Xenograft models in vivo showed that tumor growth was significantly reduced in mAb-treated mice. Similarly, stable growth inhibition of cancer cell lines was achieved by down-regulation of CD24 expression using short hairpin RNA (shRNA). The produced clones proliferated more slowly, reached lower saturation densities, and showed impaired motility. Most importantly, down-regulation of CD24 retarded tumorigenicity of human cancer cell lines in nude mice. Microarray analysis revealed a similar pattern of gene expression alterations when cells were subjected to anti-CD24 mAb or shRNA. Genes in the Ras pathway, mitogenactivated protein kinase, or BCL-2 family and others of oncogenic association were frequently down-regulated. As a putative new oncogene that is overexpressed in gastrointestinal malignancies early in the carcinogenesis process, CD24 is a potential target for early intervention in the prevention and treatment of cancer.
Targeting CD24 for treatment of colorectal and pancreatic cancer by monoclonal antibodies or small interfering RNA.
Specimen part, Cell line
View SamplesAsthma is a heterogeneous disease. Exercise-induced bronchoconstriction (EIB) is a distinct syndrome that occurs in 30-50% of asthmatics and is characterized by high levels of pro-inflammatory eicosanoids. We identified genes differentially expressed in the airways of asthmatics with EIB relative to asthmatics without EIB. Genes related to epithelial repair and mast cell infiltration including beta-tryptase and carboxypeptidase A3 were upregulated by exercise challenge in the asthma group with EIB. We confirmed that two novel mediators trefoil factor 3 (TFF3) and transglutaminase 2 (TGM2) have increased expression in airways cells and secreted product in the airways. In vitro studies indicate that 1) TFF3 induces nitric oxide synthase in airway epithelial cells from asthmatics and 2) TGM2 augments the enzymatic activity of secreted phospholipase A2 (sPLA2) group X, an enzyme recently been implicated in asthma pathogenesis. Since PLA2 serves as the first rate-limiting step leading to eicosanoid generation, these results suggest that TGM2 may be a key initiator of the airway inflammatory cascade in asthma.
Transglutaminase 2, a novel regulator of eicosanoid production in asthma revealed by genome-wide expression profiling of distinct asthma phenotypes.
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View SamplesMyocardial infarction (MI) leads to activation of cardiac fibroblasts (aCFs) and at the same time induces the formation of epicardium-derived cells at the heart surface. To discriminate between the two cell populations, we elaborated a fast and efficient protocol for the simultaneous isolation and characterization of aCFs and epicardial stromal cells (EpiSCs) from the infarcted mouse heart. For the isolation of aCFs and EpiSCs, infarcted hearts (50 min ischaemia/reperfusion) were digested by perfusion with a collagenase-containing medium for only 8 min, while EpiSCs were enzymatically removed from the outside by applying mild shear forces via a motor driven device.
Novel technique for the simultaneous isolation of cardiac fibroblasts and epicardial stromal cells from the infarcted murine heart.
Specimen part
View SamplesThe discovery of fetal mRNA transcripts in maternal circulation holds great promise for noninvasive prenatal diagnosis. To identify potential fetal biomarkers, we studied whole blood and plasma transcripts common to term pregnant women and their newborns but reduced or absent in the postpartum mothers.
Gene expression analysis in pregnant women and their infants identifies unique fetal biomarkers that circulate in maternal blood.
Specimen part
View SamplesSelective serotonin reuptake inhibitors (SSRIs) such as fluoxetine are the most common treatment for major depression. However, approximately 50% of depressed patients fail to achieve an effective treatment response. Understanding how gene expression systems relate to treatment responses may be critical for understanding antidepressant resistance. Transcriptome profiling allows for the simultaneous measurement of expression levels for thousands of genes and the opportunity to utilize this information to determine mechanisms underlying antidepressant treatment responses. However, the best way to relate this immense amount of information to treatment resistance remains unclear. We take a novel approach to this question by examining dentate gyrus transcriptomes from the perspective of a stereotyped fluoxetine-induced gene expression program. Expression programs usually represent stereotyped changes in expression levels that occur as cells transition phenotypes. Fluoxetine will shift transcriptomes so they lie somewhere between a baseline state and a full-response at the end of the program. The position along this fluoxetine-induced gene expression program (program status) was measured using principal components analysis (PCA). The same expression program was initiated in treatment-responsive and resistant mice but treatment response was associated with further progression along the fluoxetine-induced gene expression program. The study of treatment-related differences in gene expression program status represents a novel way to conceptualize differences in treatment responses at a transcriptome level. Understanding how antidepressant-induced gene expression program progression is modulated represents an important area for future research and could guide efforts to develop novel augmentation strategies for antidepressant treatment resistant individuals.
Global state measures of the dentate gyrus gene expression system predict antidepressant-sensitive behaviors.
Sex, Specimen part, Treatment
View SamplesShort sleep duration is associated with adverse metabolic, cardiovascular, and inflammatory effects. Co-twin study methodologies account for familial (e.g., genetics and shared environmental) confounding, allowing assessment of subtle environmental effects, such as the effect of short habitual sleep duration on gene expression. Therefore, we sought to investigate gene expression in monozygotic twins discordant for actigraphically phenotyped habitual sleep duration. Eleven healthy monozygotic twin pairs (82% female; mean age 42.7 years; SD=18.1), selected based on subjective sleep duration discordance, were objectively phenotyped for habitual sleep duration with two-weeks of wrist actigraphy. Peripheral blood leukocyte (PBL) RNA from fasting blood samples was obtained on the final day of actigraphic measurement and hybridized to Illumina humanHT-12 microarrays. Differential gene expression was determined between paired samples and mapped to functional categories using Gene Ontology. Next, a more comprehensive gene set enrichment analysis was performed based on the entire PBL transcriptome. The mean 24 hour sleep duration of the total sample was 439.2 minutes (SD=46.8 minutes; range 325.4 to 521.6 minutes). Mean within-pair sleep duration difference per 24 hours was 64.4 minutes (SD=21.2; range 45.9 to 114.6 minutes). The twin cohort displayed distinctive pathway enrichment based on sleep duration differences. Short sleep was associated with up-regulation of genes involved in transcription, ribosome, translation and oxidative phosphorylation. Unexpectedly, genes down-regulated in short sleep twins were highly enriched in immuno-inflammatory pathways such interleukin signaling and leukocyte activation, as well as developmental programs, coagulation cascade, and cell adhesion. Objectively assessed habitual sleep duration in monozygotic twin pairs appears to be associated with distinct patterns of differential gene expression and pathway enrichment. By accounting for familial confounding and measuring real life sleep duration, our study shows the transcriptomic effects of short sleep on dysregulated immune response and provides a potential link between sleep deprivation and adverse metabolic, cardiovascular and inflammatory outcomes.
Transcriptional Signatures of Sleep Duration Discordance in Monozygotic Twins.
Specimen part
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