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GSE22291
Mus musculus
12 Downloadable Samples
Description
Wallerian degeneration (WD) involves the fragmentation of axonal segments disconnected from their cell bodies, segmentation of the myelin sheath, and removal of debris by Schwann cells and immune cells. The removal and downregulation of myelin-associated inhibitors of axonal regeneration and synthesis of growth factors by these two cell types are critical responses to successful nerve repair. Here, we analyzed the transcriptome of the sciatic nerve of mice carrying the Wallerian degeneration slow (WldS) mutant gene, a gene that confers axonal protection in the distal stump after injury, therefore causing significant delays in WD, neuroinflammation, and axonal regeneration.
Publication Title
Transcriptional profiling of the injured sciatic nerve of mice carrying the Wld(S) mutant gene: identification of genes involved in neuroprotection, neuroinflammation, and nerve regeneration.
Sample Metadata Fields
Specimen part, Time
View Samples- Mus musculus
- 10 Downloadable Samples
Description
Astrogliosis is a hallmark of the response to brain ischemia, comprised of changes in gene expression and morphology. Hsp72 protects from cerebral ischemia, and although several mechanisms of protection have been investigated, effects on astrocyte activation are unknown. To identify potential mechanisms of protection, gene expression was assessed in mice subjected to middle cerebral artery (MCAO) or sham surgery, of either wildtype (WT) or Hsp72-overexpressing (Hsp72Tg) mice. After stroke, both genotypes exhibited genes related to cell death, stress response, and immune response. Furthermore, genes indicative of astrocyte activation, including cytoskeletal proteins and cytokines, were upregulated. To measure astrocyte activation after stroke, detailed histological and morphological analyses were performed in the cortical penumbra after stroke using unbiased stereology. Consistent with other reports, we observed a marked and persistent increase in glial fibrillary acidic protein (GFAP ) as soon as 3 hours after MCAO. In contrast, vimentin immunoreactivity appeared 12-24 hours after stroke, peaked at 72 hours, and returned to baseline after 30 days. Surprisingly, no change in overall astrocyte number was observed based on glutamine synthetase (GS) immunoreactivity. To determine if Hsp72Tg mice exhibited altered astrocyte activation compared to WT controls, morphological evaluation by fractal analysis was used. Overexpression of Hsp72 reduced astrocyte cell area, arbor area, and to a lesser extent fractal dimension, 72 hours following stroke. In conclusion, in vivo overexpression of Hsp72 alters gene expression following stroke, including genes involved in astrocyte activation, and decreases astrocyte activation acutely following MCAO. Thus, modulation of astrogliosis may be a neuroprotective mechanism exerted by Hsp72 after ischemia.
Publication Title
Effects of heat shock protein 72 (Hsp72) on evolution of astrocyte activation following stroke in the mouse.
Sample Metadata Fields
Sex, Treatment
View Samples- Mus musculus
- 5 Downloadable Samples
Description
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.
Publication Title
PTEN-deficient intestinal stem cells initiate intestinal polyposis.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 11 Downloadable Samples
Description
The transcriptional control of CNS myelin gene expression is poorly understood. Here we identify gene model 98, which we have named Myelin-gene Regulatory Factor (MRF), as a transcriptional regulator required for CNS myelination. Within the CNS, MRF is specifically expressed by postmitotic oligodendrocytes. MRF is a nuclear protein containing an evolutionarily conserved DNA binding domain homologous to a yeast transcription factor. Knockdown of MRF in oligodendrocytes by RNA interference prevents expression of most CNS myelin genes; conversely, overexpression of MRF within cultured oligodendrocyte progenitors or the chick spinal cord promotes expression of myelin genes. In mice lacking MRF within the oligodendrocyte lineage, pre-myelinating oligodendrocytes are generated but display severe deficits in myelin gene expression and fail to myelinate. These mice display severe neurological abnormalities, and die due to seizures during the third postnatal week. These findings establish MRF as a critical transcriptional regulator essential for oligodendrocyte maturation and CNS myelination.
Publication Title
Myelin gene regulatory factor is a critical transcriptional regulator required for CNS myelination.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 107 Downloadable Samples
Description
In this study that was specifically designed to identify early stages of glaucoma in DBA/2J mice, we used genome-wide expression profiling and a series of computational methods. Our methods successfully subdivided eyes with no detectable glaucoma by conventional assays into molecularly defined stages of disease. These stages represent a temporally ordered sequence of glaucoma states. Using an array of tools, we then determined networks and biological processes that are altered at these early stages. Our strategy proved very sensitive, suggesting that similar approaches will be valuable for uncovering early processes in other complex, later-onset diseases. Early changes included upregulation of both the complement cascade and endothelin system, and so we tested the therapeutic value of separately inhibiting them. Mice with a mutation in the complement component 1a gene (C1qa) were robustly protected from glaucoma with the protection being among the greatest reported. Similarly, inhibition of the endothelin system was strongly protective. Since EDN2 is potently vasoconstrictive and was produced by microglial/macrophages, our data provide a novel link between these cell types and vascular dysfunction in glaucoma. Targeting early events such as the upregulation of the complement and endothelin pathways may provide effective new treatments for human glaucoma.
Publication Title
Molecular clustering identifies complement and endothelin induction as early events in a mouse model of glaucoma.
Sample Metadata Fields
Sex, Age, Specimen part
View Samples- Mus musculus
- 8 Downloadable Samples
Description
Using EphB2 or the ISC marker Lgr5, we have FACS-purified and profiled intestinal stem cells (ISCs), crypt proliferative progenitors and late transient amplifying cells to define a gene expression program specific for normal ISCs.
Publication Title
The intestinal stem cell signature identifies colorectal cancer stem cells and predicts disease relapse.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 1 Downloadable Sample
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Microcephaly gene links trithorax and REST/NRSF to control neural stem cell proliferation and differentiation.
Sample Metadata Fields
Time
View Samples- Mus musculus
- 40 Downloadable Samples
Description
Temporal changes of gene expression from 1-wk- to 4-wk and 8-wk-old mouse in heart, kidney and lung. Mammalian somatic growth is rapid in early postnatal life but then slows and eventually ceases in multiple tissues. We hypothesized that there exists a postnatal gene expression program that is common to multiple tissues and is responsible for this coordinate growth deceleration. Consistent with this hypothesis, microarray analysis identified >1600 genes that were regulated with age coordinately in kidney, lung, and heart of juvenile mice, including many genes that regulate proliferation. As examples, we focused on three growth-promoting genes, Igf2, Mest, and Peg3, that were markedly downregulated with age. We conclude that there exists an extensive genetic program occurring during postnatal life. Many of the involved genes are regulated coordinately in multiple organs, including many genes that regulate cell proliferation. At least some of these are themselves apparently regulated by growth, suggesting that, in the embryo, a gene expression pattern is established that allows for rapid somatic growth of multiple tissues but then, during postnatal life, this growth leads to negative-feedback changes in gene expression that in turn slow and eventually halt somatic growth, thus imposing a fundamental limit on adult body size.
Publication Title
An extensive genetic program occurring during postnatal growth in multiple tissues.
Sample Metadata Fields
Sex, Age, Specimen part
View Samples- Mus musculus
- 12 Downloadable Samples
- Affymetrix Mouse Gene 2.0 ST Array (mogene20st)
Description
The perinatal period and early infancy are considered critical periods for lung development, and adversities during this period are believed to impact lung health in adulthood.The main factors affecting postnatal lung development and growth include environmental exposures, cigarette smoking, (viral) infections, allergic sensitization, and asthma.Therefore, we hypothesized that concomitant exposure in the early postnatal period in mice would cause more profound alterations in lung alveolarization and growth in adult life, quantified by stereology, and differently modulate lung inflammation and gene expression than either insult alone.Five-day-old male mice were immunized intraperitoneally (i.p.) with 10 µg of ovalbumin (OVA). This procedure was repeated at the 7th day of life, animals from the control group received i.p. injection of PBS only. Mice were exposed to either ambient PM2.5 or filtered air from the 5th to the 39th day of life, using an ambient particle concentrator developed at the Harvard School of Public Health (HAPC).Total RNA of lung samples (n=3 animals per group) was extracted using RNeasy Mini Kit (Qiagen, Hilden, Germany), according to manufacturer's instructions. The microarray analysis was performed using three RNA samples for each studied group (Control, OVA, PM2.5, OVA+PM2.5), totalizing 12 samples. One hundred nanograms of total RNA was amplified with the Ambion WT Expression Kit and hybridized onto the GeneChip Mouse Gene 2.0 ST Array (Thermo Scientific, Massachusetts, USA), following manufacturer’s protocol. The comparison between the control and OVA group exhibit 32 DEGs (28 up-regulated and 4 down-regulated), between the control and PM2.5 group had 6 DEGs (4 up and 2 down) and between the control and OVA+PM2.5 group had 5 DEGs (4 up and 1 down). The comparison between OVA and PM2.5 group showed 97 DEGS (22 up and 75 down) and between OVA and OVA+PM2.5 group had 7 DEGs (4 up and 3 down). Finally, the comparison between the PM2.5 and OVA+PM2.5 group exhibit 34 DEGs (2 up and 32 down).Our experimental data provide pathological support for the hypothesis that either allergic or environmental insults in early life have permanent adverse consequences to lung growth. In addition, combined insults were associated with the development of a COPD-like phenotype in young adult mice.
Publication Title
Allergic sensitization and exposure to ambient air pollution beginning early in life lead to a COPD-like phenotype in young adult mice.
Sample Metadata Fields
Treatment
View Samples- Mus musculus, Homo sapiens
- 2 Downloadable Samples
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
STAT6 transcription factor is a facilitator of the nuclear receptor PPARγ-regulated gene expression in macrophages and dendritic cells.
Sample Metadata Fields
Specimen part, Treatment, Subject, Time
View Samples