Intestinal polyposis, a precancerous neoplasia, results primarily from an abnormal increase in the number of crypts. Crypts contain intestinal stem cells (ISCs). Thus intestinal polyposis provides an ideal condition for studying stem cell involvement in polyp/tumor formation. Using a conditional knock-out mouse model, we found that the tumor suppressor Phosphatase of Tension homolog (PTEN) governs the proliferation rate and number of ISCs and loss of PTEN results in an excess of ISCs. In PTEN mutants, excess ISCs initiate de-novo crypt formation and crypt fission, recapitulating crypt production in fetal/neonatal intestine. Microarray studies were used to profile the changes in gene expression that occurred when PTEN was knocked out in the intestine.
PTEN-deficient intestinal stem cells initiate intestinal polyposis.
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View SamplesLoss and heterozygosity for NDR1 predisposes mice to T-cell lymphoma development. To analyze mechanisms of tumor development in these mice chemically (ENU)-induced tumors were collected and RNA was extracted.
Ablation of the kinase NDR1 predisposes mice to the development of T cell lymphoma.
Sex, Specimen part, Disease, Treatment
View SamplesAlthough the induction of C-FOS in the brain has been extensively studied for several decades to date there has been no attempt to identify the targets of C-FOS at a genome wide level, and it was not known how many genes C-FOS activates in a given cell. To identify potential C-FOS target genes, we performed microarray analysis on RNA obtained from mouse cortical (mCTX) neurons infected with lentivirus containing either a control shRNA (targeting firefly luciferase) or c-Fos shRNA that were subsequently depolarized with 0, 1, 3, or 6 hours of KCl.
Genome-wide identification and characterization of functional neuronal activity-dependent enhancers.
Specimen part
View SamplesFast-spiking (FS) interneurons are important elements of neocortical circuitry that constitute the primary source of synaptic inhibition in adult cortex and impart temporal organization on ongoing cortical activity. The highly specialized intrinsic membrane and firing properties that allow cortical FS interneurons to perform these functions are attributable to equally specialized gene expression, which is ultimately coordinated by cell-type-specific transcriptional regulation. Although embryonic transcriptional events govern the initial steps of cell-type specification in most cortical interneurons, including FS cells, the electrophysiological properties that distinguish adult cortical cell types emerge relatively late in postnatal development, and the transcriptional events that drive this maturational process are not known. To address this, we used mouse whole-genome microarrays and whole-cell patch clamp to characterize the transcriptional and electrophysiological maturation of cortical FS interneurons between postnatal day 7 (P7) and P40. We found that the intrinsic and synaptic physiology of FS cells undergoes profound regulation over the first 4 postnatal weeks and that these changes are correlated with primarily monotonic but bidirectional transcriptional regulation of thousands of genes belonging to multiple functional classes. Using our microarray screen as a guide, we discovered that upregulation of two-pore K leak channels between P10 and P25 contributes to one of the major differences between the intrinsic membrane properties of immature and adult FS cells and found a number of other candidate genes that likely confer cell-type specificity on mature FS cells.
Transcriptional and electrophysiological maturation of neocortical fast-spiking GABAergic interneurons.
Specimen part
View SamplesBMPR2 mutation causes pulmonary arterial hypertension (PAH); ACE2 treatment can resolve established BMPR2-mediated PAH. The purpose of this study was to uncover the molecular mechanism behind this.
Cytoskeletal defects in Bmpr2-associated pulmonary arterial hypertension.
Sex, Specimen part, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Redeployment of Myc and E2f1-3 drives Rb-deficient cell cycles.
Specimen part
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