It has been reported that repeated intra-tracheal instillation of S. chartarum spores induced significant pulmonary arterial remodeling in mice, which resulted in pathological changes like human pulmonary arterial hypertension (PAH) and elevation right ventricle systolic pressure.
Gene expression analysis of a murine model with pulmonary vascular remodeling compared to end-stage IPAH lungs.
Sex, Specimen part, Disease, Disease stage
View SamplesOur previous investigation indicated that high-virulence C. gattii (C. gattii TIMM 4097) tend to reside in the alveoli, whereas low-virulence C. gattii (C. gattii TIMM 4903) tend to be washed out from the alveoli and move into the central side of the respiratory system. To test this hypothesis, we performed microarray assay.
How histopathology can contribute to an understanding of defense mechanisms against cryptococci.
Sex, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Intestinal master transcription factor CDX2 controls chromatin access for partner transcription factor binding.
Specimen part
View SamplesA congenic mouse line was constructed by introgressing a C3H chromosome 9 region harboring Ath29 into the C57BL/6 apoE-deficient background. RNA was extracted from aorta using a QIAGEN kit . Total RNA was pooled in an equal amount from 3 mice for each group. Standard Affymetrix procedures were performed using 8ug of total RNA.
Characterization of Ath29, a major mouse atherosclerosis susceptibility locus, and identification of Rcn2 as a novel regulator of cytokine expression.
Disease, Disease stage
View SamplesCardiac hypertrophy can lead to heart failure, and is induced either by physiological stimuli eg postnatal development, chronic exercise training or pathological stimuli eg pressure or volume overload. Majority of new therapies for heart failure has mixed outcomes. A combined mouse model and oligo-array approach are used to examine whether phosphoinositide 3-kinase (p110-alpha isoform) activity is critical for maintenance of cardiac function and long-term survival in a setting of heart failure. The significance and expected outcome are to recognise genes involved in models of heart failure ie pathological- vs physiology-hypertrophy, and examine the molecular mechanisms responsible for such activity.
PI3K(p110 alpha) protects against myocardial infarction-induced heart failure: identification of PI3K-regulated miRNA and mRNA.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Aberrant silencing of imprinted genes on chromosome 12qF1 in mouse induced pluripotent stem cells.
Specimen part
View SamplesHuntingtons disease (HD) involves marked early neurodegeneration in the striatum whereas the cerebellum is relatively spared despite the ubiquitous expression of full-length mutant huntingtin, implying that inherent tissue-specific differences determine susceptibility to the HD CAG mutation. To understand this tissue specificity, we compared early mutant huntingtin-induced gene expression changes in striatum to those in cerebellum in young Hdh CAG knock-in mice, prior to onset of evident pathological alterations. Endogenous levels of full-length mutant huntingtin caused qualitatively similar, but quantitatively different gene expression changes in the two brain regions. Importantly, the quantitatively different responses in striatum and cerebellum in mutant mice were well accounted for by the intrinsic molecular differences in gene expression between striatum and cerebellum in wild-type animals. Tissue-specific gene expression changes in response to the HD mutation, therefore, appear to reflect the different inherent capacities of these tissues to buffer qualitatively similar effects of mutant huntingtin. These findings highlight a role for intrinsic quantitative tissue differences in contributing to HD pathogenesis, and likely to other neurodegenerative disorders exhibiting tissue-specificity, thereby guiding the search for effective therapeutic interventions.
Differential effects of the Huntington's disease CAG mutation in striatum and cerebellum are quantitative not qualitative.
Specimen part
View SamplesCell differentiation requires epigenetic modulation of tissue-specific genes and activities of master transcriptional regulators, which are recognized for their dominant control over cellular programs. Using novel epigenomic methods, we characterized enhancer elements specifically modified in differentiating intestinal epithelial cells and found enrichment of transcription factor-binding motifs corresponding to CDX2, a master regulator of the intestine. Directed investigation revealed surprising lability in CDX2 occupancy of the genome, with redistribution from hundreds of sites occupied only in progenitors to thousands of new sites in mature cells. Knockout mice confirmed distinct Cdx2 requirements in dividing and differentiated adult intestinal cells, including responsibility for the active enhancer configuration associated with maturity. Dynamic CDX2 occupancy corresponds with condition-specific gene expression and, importantly, to differential co-occupancy with other tissue-restricted transcription factors: HNF4A in mature cells and GATA6 in progenitors. These results reveal dynamic, context-specific functions and mechanisms of a master transcription factor within a cell lineage.
Differentiation-specific histone modifications reveal dynamic chromatin interactions and partners for the intestinal transcription factor CDX2.
Specimen part, Cell line
View SamplesHuntington's disease (HD) features a unique disease-initiating mechanism hypothesized to entail an impact of the CAG repeat encoded polyglutamine region on the full-length huntingtin protein, with dominant effects that are continuous with CAG size, in a simple gain of function. To evaluate these predictions, we generated a series of heterozygous Hdh CAG knock-in mouse embryonic stem (ES) cell lines, with 18, 48, 89, 109 CAGs, and found that a continuous analytic strategy efficiently identified, from genome-wide datasets, 73 genes and 172 pathways whose expression varied continuously with CAG length. The CAG-correlated genes were distinct from the set of 754 genes that distinguished huntingtin null ES cells from wild-type controls, and CAG-correlated pathways did not display a one-to-one correspondence with the 238 pathways altered in huntingtin null ES cells. Rather, the genes that varied with CAG size were either members of the same pathways as altered genes in huntingtin null cells or were members of unique pathways related to these pathways. These findings falsified a gain of function/loss of function proposal but were consistent with the simple gain of novel function mechanism hypothesis. The dominant CAG correlated gene expression changes conformed to the genetic features of the HD initiating mechanism and were system-wide and inter-related with pathways perturbed by lack of full-length huntingtin function, urging system-wide approaches for the discovery and validation of potential modulating factors, in the search for effective HD therapeutics.
HD CAG-correlated gene expression changes support a simple dominant gain of function.
Cell line
View SamplesHistone H3 lysine 9 (H3K9) methylation is an epigenetic mark of transcriptionally repressed chromatin. During mammalian development, H3K9 methylation levels seem to be spatiotemporally regulated by the opposing activities of methyltransferases and demethylases to govern correct gene expression. However, the combination(s) of H3K9 methyltransferase(s) and demethylase(s) that contribute to this regulation and the genes regulated by them remain unclear. Herein, we demonstrate the essential roles of H3K9 demethylases Jmjd1a and Jmjd1b in the embryogenesis and viability control of embryonic stem (ES) cells. Mouse embryos lacking Jmjd1a/Jmjd1b died after implantation. Depletion of Jmjd1a/Jmjd1b in mouse ES cells induced rapid cell death accompanied with a massive increase in H3K9 methylation. Jmjd1a/Jmjd1b depletion induced an increase in H3K9 methylation in the gene-rich regions of the chromosomes, indicating that Jmjd1a/Jmjd1b removes H3K9 methylation marks in the euchromatin. Importantly, the additional disruption of the H3K9 methyltransferase G9a in a Jmjd1a/Jmjd1b-deficient background rescued not only the H3K9 hypermethylation phenotype but also the cell death phenotype. We also found that Jmjd1a/Jmjd1b removes H3K9 methylation marks deposited by G9a in the Oct4 and Ccnd1 loci to activate transcription. In conclusion, Jmjd1a/Jmjd1b ensures ES cell viability by antagonizing G9a-mediated H3K9 hypermethylation in the gene-rich euchromatin.
Combined Loss of JMJD1A and JMJD1B Reveals Critical Roles for H3K9 Demethylation in the Maintenance of Embryonic Stem Cells and Early Embryogenesis.
Specimen part
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