Chromatin remodelling provides a key mechanism for the regulation of gene expression through dynamic alterations in nucleosome occupancy at promoters and enhancers. Haploinsufficiency for the ATP-dependent chromatin remodeller chromodomain-helicase-DNA-binding protein 7 (CHD7) causes human CHARGE syndrome. CHARGE is characterised by a distinct pattern of congenital anomalies, including cardiovascular malformations, and has traditionally been considered a neurocristopathy. We present a new perspective, by showing severe structural cardiovascular defects following ablation of Chd7 in the anterior mesoderm and other cardiac-related lineages. We identify multiple downstream pathways affected by the loss of Chd7 and disruption of excitation-contraction coupling in cardiomyocytes. Furthermore, we demonstrate CHD7 binding at the Sema3C promoter and alterations to the local chromatin structure in vivo, indicating direct transcriptional regulation. This work therefore provides novel insights into the etiology of heart defects arising in CHARGE syndrome and reveals a requirement for CHD7 activity in mesodermal cardiac progenitors.
A critical role for the chromatin remodeller CHD7 in anterior mesoderm during cardiovascular development.
Specimen part
View SamplesBecause most human stroke victims are elderly, studies of experimental stroke in the aged rather than the young rat model may be optimal for identifying clinically relevant cellular responses, as well for pinpointing beneficial interventions.
Transcriptomics of post-stroke angiogenesis in the aged brain.
Sex, Age, Specimen part
View SamplesAged humans and rodents are susceptible to infection with Streptococcus pneumoniae bacteria as a result of an inability to make antibodies to capsular polysaccharides. This is partly a result of decreased production of proinflammatory cytokines and increased production of interleukin (IL)-10 by macrophages (Mphi) from aged mice. To understand the molecular basis of cytokine dysregulation in aged mouse Mphi, a microarray analysis was performed on RNA from resting and lipopolysaccharide (LPS)-stimulated Mphi from aged and control mice using the Affymetrix Mouse Genome 430 2.0 gene chip. Two-way ANOVA analysis demonstrated that at an overall P < 0.01 level, 853 genes were regulated by LPS (169 in only the young, 184 in only the aged, and 500 in both). Expression analysis of systematic explorer revealed that immune response (proinflammatory chemokines, cytokines, and their receptors) and signal transduction genes were specifically reduced in aged mouse Mphi. Accordingly, expression of Il1 and Il6 was reduced, and Il10 was increased, confirming our previous results. There was also decreased expression of interferon-gamma. Genes in the Toll-like receptor-signaling pathway leading to nuclear factor-kappaB activation were also down-regulated but IL-1 receptor-associated kinase 3, a negative regulator of this pathway, was increased in aged mice. An increase in expression of the gene for p38 mitogen-activated protein kinase (MAPK) was observed with a corresponding increase in protein expression and enzyme activity confirmed by Western blotting. Low doses of a p38 MAPK inhibitor (SB203580) enhanced proinflammatory cytokine production by Mphi and reduced IL-10 levels, indicating that increased p38 MAPK activity has a role in cytokine dysregulation in the aged mouse Mphi.
Molecular basis of age-associated cytokine dysregulation in LPS-stimulated macrophages.
Specimen part
View SamplesVarious substances have been reported to enhance the cardiac differentiation of embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). Ascorbic Acid had a cardiogenic effect in mESC CGR8 cell line. Transcriptome of AA-treated CGR8 ESCs did not reveal any significant changes in gene expression as compared to untreated cells.
Ascorbic Acid-Induced Cardiac Differentiation of Murine Pluripotent Stem Cells: Transcriptional Profiling and Effect of a Small Molecule Synergist of Wnt/β-Catenin Signaling Pathway.
Specimen part, Cell line
View SamplesWe sequenced whole adipose tissue from control and LCMV infected mice 6dpi, in control vs T cell-specific IFNAR knockoutmice to understand the transcriptional changes in adipose tissue upon loss of type I IFN-T cell singaling axis, and how it contributes to cachexia. Overall design: inguinal fat pad (after removing iLN) was used for sequencing in control and infected mice (LCMV clone13 2x10^6PFU), this was done in two genotypes (IFNARfl/fl) as controls, vs (IFNARfl/fl-CD4cre/+) as T-cell specific IFNAR knockouts.
CD8<sup>+</sup> T cells induce cachexia during chronic viral infection.
Specimen part, Subject
View SamplesDamage to and/or loss of sensory neurons can result in debilitating neuropathies that often have a dramatic impact on quality of life. The cellular mechanisms involved in the response of neurons and glia to such pathological insults are poorly understood. Investigation has shown that peripheral glia play critical roles in both the degenerative and regenerative processes that are involved in the responses to peripheral nerve damage. The vast majority of studies have focused primarily on myelinating Schwann cells], with the result that very little is known regarding how the non-myelinating glia that ensheath axons and neuronal somas respond to nerve damage. This is a significant knowledge gap, given that over 80% of cutaneous fibers are unmyelinated, that they transduce such important modalities as itch, pain, temperature, touch and pressure, and that they are affected in many prevalent peripheral neuropathies. It is the goal of this study to shed light on the genetic programs involved in the responses of non-myelinating glia roles to nerve degeneration. We utilized RNA-seq to identify genes that were differentially expressed in the larval head during the process of sensory neuron ablation and axon degeneration in both wild-type larvae and in larvae that do not have peripheral glia (foxd3 mutants) using a selective, conditional approach. Overall, the information regarding differential gene expression in these conditions will provide a basis for further investigation into the cellular processes that underlie pathophysiological responses of neurons and glia to sensory nerve damage. Overall design: mRNA levels were determined using biological triplicate samples from five sets of samples. Three sets from wild-type: control, 2 hrs of metronidazole treatment and 5 hrs of metronidazole treatment. And two sets from foxd3 mutants: control and 5hrs of metronidazole treatment.
Transcriptome Analysis of Chemically-Induced Sensory Neuron Ablation in Zebrafish.
No sample metadata fields
View SamplesTienilic acid (TA) was withdrawn from the US market due to numerous cases of liver necrosis. Two major hypotheses currently used to understand the mechanisms of idiosyncratic reactions such as TA-induced hepatotoxicity are the hapten and danger hypotheses. Both human cytochrome (CYP) P450 2C9 and the rat ortholog CYP 2C11 metabolize TA, and it was reported that a reactive metabolite of TA binds almost exclusively to these enzymes, thus acting as a mechanism-based inhibitor. TA-induced liver toxicity is associated with antibodies against CYP 2C9, thus TA appears to act as a hapten. However, if the binding were limited to CYP 2C, it is unlikely that this would lead to significant cell stress. Thus, if TA does not cause cell stress it would suggest that a drug does not have to generate a danger signal in order to cause an idiosyncratic drug reaction and acting as a hapten is sufficient. In order to test whether TA can cause cell stress, male Sprague Dawley rats were orally dosed with TA, and hepatic gene expression was profiled at 6 and 24 h after drug administration.
Changes in gene expression induced by tienilic Acid and sulfamethoxazole: testing the danger hypothesis.
No sample metadata fields
View SamplesExpression analysis of 36 pancreatic ductal adenocarcinoma tumors and matching normal pancreatic tissue samples from pancreatic cancer patients of the Clinical Institute Fundeni (ICF) using Affymetrix U133 Plus 2.0 whole-genome chips.
Combined gene expression analysis of whole-tissue and microdissected pancreatic ductal adenocarcinoma identifies genes specifically overexpressed in tumor epithelia.
Subject
View SamplesAlzheimer's disease (AD) is a devastating neurodegenerative disorder that threatens to reach epidemic proportions as our population ages. Although much research has examined molecular pathways associated with AD, relatively few studies have focused on critical early stages. Our prior microarray study correlated gene expression in human hippocampus with AD markers. Results suggested a new model of early-stage AD in which pathology spreads along myelinated axons, orchestrated by upregulated transcription and epigenetic factors related to growth and tumor suppression (Blalock et al., 2004). However, the microarray analyses were performed on RNA from fresh frozen hippocampal tissue blocks containing both gray and white matter, potentially obscuring region-specific changes. In the present study, we used laser capture microdissection to exclude major white matter tracts and selectively collect CA1 hippocampal gray matter from formalin-fixed, paraffin-embedded (FFPE) hippoc ampal sections of the same subjects assessed in our prior study. Microarray analyses of this gray matter-enriched tissue revealed many correlations similar to those seen in our prior study, particularly for neuron-related genes. Nonetheless, in the laser-captured tissue, we found a striking paucity of the AD-associated epigenetic and transcription factor genes that had been strongly overrepresented in the prior tissue block study. In addition, we identified novel pathway alterations that may have considerable mechanistic implications, including downregulation of genes stabilizing ryanodine receptor Ca2+ release and upregulation of vascular development genes. We conclude that FFPE tissue can be a reliable resource for microarray studies, that upregulation of growth-related epigenetic/ transcription factors with incipient AD is predominantly localized to white matter, further supporting our prior findings and model, and that alterations in vascular and ryanodine receptor-relat ed pathways in gray matter are closely associated with incipient AD.
Microarray analyses of laser-captured hippocampus reveal distinct gray and white matter signatures associated with incipient Alzheimer's disease.
Sex, Age, Disease
View SamplesMacrophages play a critical role in the pathogenesis of many diseases, including rheumatoid arthritis, inflammatory bowel disease and atherosclerosis. Monocytes recruited into tissues from peripheral blood differentiate into macrophages. There is limited data concerning the global changes in the expression of genes during monocyte to macrophage, and how the patterns of change identify the mechanism contributing to differentiation or macrophage function. Employing the microarray technology, we examined the transcriptional profile of in vitro adherence-induced differentiation of primary human monocytes into macrophages. We found the significant up regulation of genes contributing to the functions of macrophage, including signature patterns defining the induction of genes contributing to immunity and defense; lipid, fatty acid and steroid metabolism; cell adhesion and; carbohydrate metabolism; amino acid metabolism and endocytosis. In contrast, a variety of transcription factors were down regulated during monocyte to macrophage differentiation, suggesting that transcriptional repression may be important for the transition from monocytes to macrophages. However, a limited number of transcription factors were up regulated, among these was C/EBPA, which may contribute to differentiation by regulating down stream genes, which a characteristic of differentiated macrophages. These observations suggest that examination of the transcriptional profile in monocytes and macrophages in patients may identify relevant therapeutic targets in diseases such as rheumatoid arthritis and atherosclerosis.
Transcriptional diversity during monocyte to macrophage differentiation.
No sample metadata fields
View Samples