RhoB null mice show decreases in pathological angiogenesis in the ischemic retina and reduces angiogenesis in response to cutaneous wounding, but enhances lymphangiogenesis following both dermal wounding and inflammatory challenge.
RhoB controls coordination of adult angiogenesis and lymphangiogenesis following injury by regulating VEZF1-mediated transcription.
Sex, Specimen part
View SamplesInduction of the Arf tumor suppressor in response to hyperproliferative stress following oncogene activation activates a p53-dependent transcriptional program that limits the expansion of incipient cancer cells. Although Arf is not expressed in most tissues of fetal or young adult mice, it is physiologically expressed in the fetal yolk sac, a tissue derived from the extraembryonic endoderm. We demonstrate that expression of the mouse p19Arf protein marks late stages of extraembryonic endoderm differentiation in cultured embryoid bodies derived from either embryonic stem cells or induced pluripotent stem cells, and that Arf inactivation specifically delays the differentiation of the extraembryonic endoderm lineage, but not the formation of other germ cell lineages from pluripotent progenitors. Arf is required for the timely induction of extraembryonic endodermal cells in response to Ras/Erk signaling and, in turn, acts through p53 to ensure extraembryonic endoderm lineage development, but not maintenance. Remarkably, a significant temporal delay in extraembryonic endoderm differentiation detected during the maturation of Arf-null embryoid bodies is rescued by enforced expression of miR-205, a micro-RNA up-regulated by p19Arf and p53. Introduction of miR-205 into Arf-null embryonic stem cells rescues defective ExEn formation and elicits a program of gene expression that controls the migration and adhesion of embryonic endodermal cells. This occurs, at least in part, through atypical regulation of genes that control the epithelial-to-mesenchymal transition in cancer cells. Our findings suggest that noncanonical and canonical roles of Arf in extraembryonic endoderm development and tumor suppression, respectively, may be conceptually linked through mechanisms that govern cell-to-cell attachment and migration.
Arf tumor suppressor and miR-205 regulate cell adhesion and formation of extraembryonic endoderm from pluripotent stem cells.
Specimen part, Treatment
View SamplesSkin is the largest organ in the body and serves important barrier, regulatory, and sensory functions. Like other tissues, skin is subject to temporal fluctuations in physiological responses under both homeostatic and stressed states. To gain insight into these fluctuations, we investigated the role of the circadian clock in the transcriptional regulation of human epidermal samples collected in a time-ordered fashion. We also determined whether this circadian patterning could be applied to unordered (i.e., randomly collected) human epidermal samples. The purpose of this study was to gain insight into the evolutionarily-conserved rhythmic patterns of the circadian transcriptome in human skin and how it relates to published transcriptomes from other human tissues.
Population-level rhythms in human skin with implications for circadian medicine.
Sex, Specimen part
View SamplesIntroduction: Though heavy alcohol drinking has been well characterized as causing a variety of injuries, recent epidemiological evidence in humans suggests moderate consumption may provide beneficial effects. For example, there exists a J- or U-shaped relationship between the level of alcohol intake and cardiovascular disease risk. We investigated the underlying mechanisms of these positive consequences by identifying which genes are responsive to moderate alcohol intake in the liver, the primary site for alcohol metabolism. Methods: Twelve female, inbred, alcohol-preferring (iP10a) rats were split equally between chronic water exposure and voluntary chronic ethanol exposure. Hepatic cholesterol and triglyceride levels were analyzed both histologically and biochemically. Hepatic transcriptomes were paired-end sequenced on the Illumina HiScanSQ system. Reads were analyzed and mapped using CLCbio Genomics Workbench 4.9. We confirmed altered expression of a subset of genes using TaqMan-based qRT-PCR. To quantify DNA methylation, we first digested DNA with methylation sensitive restriction enzymes and then performed qPCR using TaqMan assays surrounding the digest sites. Calculating ?Ct between a mock digest and digest determines the percent methylation in that locus. Results: Voluntary alcohol consumption in iP10a rats modeled moderate consumption in humans. These levels did not result in intrahepatic fat accumulation. Sequencing produced ~1.2 Gb of sequence per sample, and 65% of reads mapped uniquely. Using a FDR corrected p value of 0.05 we found 250 altered transcripts. Ontology analysis of genes with a fold change =1.3 identified many cholesterol synthesis genes and cytoskeleton subunit genes, all of which were down-regulated. Of the 28 genes reanalyzed by qRT-PCR, altered expression was confirmed in 24 genes including the majority of the cholesterol synthesis and cytoskeleton subunit genes. Lastly, we profiled methylation throughout the promoter and gene body of four genes elicited in the RNA-Seq experiment. We found that alcohol caused demethylation at all loci; however this loss happened in a site-specific, tightly regulated manner. Conclusion: Voluntary consumption in the iP10a animals models moderate consumption in humans, does not produce intrahepatic fat accumulation, and causes down-regulation of a majority of cholesterol synthesis genes. Moderate alcohol also results in a tightly-regulated demethylation effect. Our results explain, at least in part, the J- or U-shaped relationship between level of alcohol intake and cardiovascular disease risk. Overall design: We sequenced 12 female iP10a rat hepatic transcriptomes providing 6 biological replicates for water control and 6 for ethanol treatment.
A snapshot of the hepatic transcriptome: ad libitum alcohol intake suppresses expression of cholesterol synthesis genes in alcohol-preferring (P) rats.
No sample metadata fields
View SamplesThe morphogen and mitogen, Sonic Hedgehog, activates a Gli1-dependent transcription program that drives proliferation of granule neuron progenitors (GNPs) within the external germinal layer of the postnatally developing cerebellum. Medulloblastomas with mutations activating the Sonic Hedgehog signaling pathway preferentially arise within the external germinal layer, and the tumor cells closely resemble GNPs. Atoh1/Math1, a basic helix-loop-helix transcription factor essential for GNP histogenesis, does not induce medulloblastomas when expressed in primary mouse GNPs that are explanted from the early postnatal cerebellum and transplanted back into the brains of nave mice. However, enforced expression of Atoh1 in primary GNPs enhances the oncogenicity of cells overexpressing Gli1 by almost three orders of magnitude. Unlike Gli1, Atoh1 cannot support GNP proliferation in the absence of Sonic Hedgehog signaling and does not govern expression of canonical cell cycle genes. Instead, Atoh1 maintains GNPs in a Sonic Hedgehog-responsive state by regulating genes that trigger neuronal differentiation, including many expressed in response to bone morphogenic protein-4. Therefore, by targeting multiple genes regulating the differentiation state of GNPs, Atoh1 collaborates with the pro-proliferative Gli1-dependent transcriptional program to influence medulloblastoma development.
Atoh1 inhibits neuronal differentiation and collaborates with Gli1 to generate medulloblastoma-initiating cells.
Age, Specimen part, Treatment
View SamplesMyc-driven Group 3 medulloblastoma (MB) is the most aggressive tumor among the four subgroups classified by transcriptome, genomic landscape and clinical outcomes. So far in all available mouse Group 3 models, the constitutive ectopic Myc expression was under control of LTR element or other exogenous promoters within the vectors, which were randomly inserted into the genome with multiple copies. Here we are deploying nuclease deficient CRISPR/dCas9-based transactivator that is targeted to promoter DNA sequences by specific guide RNA to force the transcriptional activation of endogenous Myc in p53-/-;cdkn2c-/- neurospheres cells. A combination of three sgRNAs together with dCas9-VP64 induced the highest expression of endogenous Myc. When the targeted cells were transplanted to the cortex of recipients, tumors arose fully recapitulate the Group 3 MB in human. This novel mouse model should significantly strengthen our understanding and treatment of the Myc-driven Group 3 medulloblastoma.
Mouse medulloblastoma driven by CRISPR activation of cellular Myc.
Specimen part
View SamplesSystemic Juvenile Idiopathic Arthritis (sJIA) has been strongly associated with macrophage activation syndrome (MAS). To better understand the pathogenesid of sJIA and to facilitate the search for MAS biomarkers, we examine gene expression profiles in untreated new onset sJIA.
Gene expression profiling of peripheral blood from patients with untreated new-onset systemic juvenile idiopathic arthritis reveals molecular heterogeneity that may predict macrophage activation syndrome.
No sample metadata fields
View SamplesDrugMatrix is a comprehensive rat toxicogenomics database and analysis tool developed to facilitate the integration of toxicogenomics into hazard assessment. Using the whole genome and a diverse set of compounds allows a comprehensive view of most pharmacological and toxicological questions and is applicable to other situations such as disease and development.
Genomic models of short-term exposure accurately predict long-term chemical carcinogenicity and identify putative mechanisms of action.
Sex, Specimen part, Compound, Time
View SamplesDrugMatrix is a comprehensive rat toxicogenomics database and analysis tool developed to facilitate the integration of toxicogenomics into hazard assessment. Using the whole genome and a diverse set of compounds allows a comprehensive view of most pharmacological and toxicological questions and is applicable to other situations such as disease and development.
Genomic models of short-term exposure accurately predict long-term chemical carcinogenicity and identify putative mechanisms of action.
Specimen part, Compound, Time
View SamplesDrugMatrix is a comprehensive rat toxicogenomics database and analysis tool developed to facilitate the integration of toxicogenomics into hazard assessment. Using the whole genome and a diverse set of compounds allows a comprehensive view of most pharmacological and toxicological questions and is applicable to other situations such as disease and development.
Genomic models of short-term exposure accurately predict long-term chemical carcinogenicity and identify putative mechanisms of action.
Sex, Specimen part, Compound, Time
View Samples