Comparatative gene expression analysis for CD4 T cell subsets isolated from peripheral blood and palatine tonsils
A methodology for global validation of microarray experiments.
Specimen part
View SamplesDNA microarrays are popular tools for measuring gene expression of biological samples. This ever increasing popularity is ensuring that a large number of microarray studies are conducted, many of which with data publicly available for mining by other investigators. Under most circumstances, validation of differential expression of genes is performed on a gene to gene basis. Thus, it is not possible to generalize validation results to the remaining majority of non-validated genes or to evaluate the overall quality of these studies. <br></br> We have devised an approach for the global validation of DNA microarray experiments that will allow researchers to evaluate the general quality of their experiment and to extrapolate validation results of a subset of genes to the remaining non-validated genes. We applied this method to a microarray experiment validated with quantitative real time polymerase chain reaction. The experiment consists of three biological replicate treatments of mouse 3T3-L1 preadipocytes with the steroid hormone dexamethasone for 3 hours. Total RNA was extracted from each of our three treatment and three control samples, and we labeled and hybridized five aliquots of each sample to Affymetrix MGU74Av2 microarrays, for a total of 30 microarrays.<br></br> We illustrate why the popular strategy of selecting only the most differentially expressed genes for validation generally fails as a global validation strategy and propose random-stratified sampling as a better gene selection method. We also illustrate shortcomings of often-used validation indices such as overlap of significant effects and the correlation coefficient and recommend the concordance correlation coefficient (CCC) as an alternative.
A methodology for global validation of microarray experiments.
Cell line, Subject, Compound
View SamplesResiquimod is a nucleoside analog belonging to the imidazoquinoline family of compounds which is known to signal through Toll-like receptor 7. Resiquimod treatment has been demonstrated to inhibit the development of allergen induced asthma in experimental models. Despite this demonstrated effectiveness, little is known about the molecular events responsible for this effect. The aim of the present study was to elucidate the molecular processes which were altered following resiquimod treatment and antigen challenge in a mouse model of allergic asthma. Employing microarray analysis, we have characterized the asthmatic transcriptome of the murine lung and determined that it includes genes involved in: the control of cell cycle progression, airway remodelling, the complement and coagulation cascades, and chemokine signalling. We have demonstrated that systemic resiquimod administration resulted in the recruitment of NK cells to the lungs of the mice, although no causal relationship between NK cell recruitment and treatment efficacy was found. Furthermore, results of our studies demonstrated that resiquimod treatment resulted in the normalization of the expression of genes involved with airway remodelling and chemokine signalling, and in the modulation of the expression of genes including cytokines and chemokines, adhesion molecules, and B-cell related genes, involved in several aspects of immune function and antigen presentation. Overall, our findings identified several genes, important in the development of asthma pathology, that were normalized following resiquimod treatment thus improving our understanding of the molecular consequences of resiquimod treatment in the lung milieu.
Modulation of the allergic asthma transcriptome following resiquimod treatment.
No sample metadata fields
View SamplesAsthma pathogenesis and susceptibility involves a complex interplay between genetic and environmental factors.
Functional classes of bronchial mucosa genes that are differentially expressed in asthma.
Sex, Specimen part
View SamplesBackground and Aims: HNF4a is a nuclear hormone receptor transcription factor that has been shown to be required for hepatocyte differentiation and development of the liver. It has also been implicated in regulating expression of genes that act in the epithelium of the lower gastrointestinal tract. This implied that HNF4a might be required for development of the gut. Methods: We generated mouse embryos in which HNF4a was ablated in the epithelial cells of the fetal colon using Cre-loxP technology. Embryos were examined using a combination of histology, immunohistochemistry, gene array and RT-PCR, and chromatin immunoprecipitation analyses to define the consequence of loss of HNF4a on colon development. Results: Embryos could be generated until E18.5 that lacked HNF4a in their colon. Although, early stages of colonic development occurred, HNF4a null colons failed to form normal crypts. In addition, goblet cell maturation was perturbed and expression of an array of genes that encode proteins with diverse roles in colon function was disrupted. Several genes whose expression in the colon was dependent on HNF4a contained HNF4abinding sites sequences within putative transcriptional regulatory regions and a subset of these sites were occupied by HNF4a in vivo. Conclusion: HNF4a is a transcription factor that is essential for development of the mammalian colon, regulates goblet cell maturation and is required for expression of genes that control normal colon function and epithelial cell differentiation.
Hepatocyte nuclear factor 4alpha is essential for embryonic development of the mouse colon.
Specimen part
View SamplesPKR is an interferon induced serine/threonine protein kinase, that is activated by double stranded RNA. PKR plays an important role in the antiviral defense by interferon. In addition to its role in translation, PKR participates in several signaling pathways to transcription. The goal of this experiment is to study the role of PKR in regulating gene expression in our NIH 3T3 inducible cell line, which could overexpress PKR wt protein after the removal of tetracycline (Donze O, Dostie J, Sonenberg N. (1999) Virology 256: 322-9).
The protein kinase PKR: a molecular clock that sequentially activates survival and death programs.
Cell line
View SamplesSeasonal influenza outbreaks and recurrent influenza pandemics present major challenges to public health. By studying immunological responses to influenza in different host species, it may be possible to discover common mechanisms of susceptibility in response to various influenza strains. This could lead to novel therapeutic targets with wide clinical application. Using a mouse-adapted strain of influenza (A/HK/1/68-MA20 [H3N2]), we produced a mouse model of severe influenza (p-flu) that reproduces the hallmark high viral load and overexpression of cytokines associated with susceptibility to p-flu in humans. We mapped genetic determinants of the host response using a panel of 29 closely related mouse strains (AcB/BcA panel of recombinant congenic strains) created from influenza-susceptible A/J and influenza-resistant C57BL/6J (B6) mice. Combined clinical quantitative trait loci (cQTL) and lung expression QTL (eQTL) mapping identified candidate genes for two sex-specific QTLs on chromosomes 2 and 17. The former includes the previously described Hc gene, a deficit of which is associated with the susceptibility phenotype in females. The latter includes the phospholipase gene Pla2g7 and Tnfrsf21, a member of the tumor necrosis factor receptor superfamily. Confirmation of the gene underlying the chromosome 17 QTL may reveal new strategies for influenza treatment.
Mapping of clinical and expression quantitative trait loci in a sex-dependent effect of host susceptibility to mouse-adapted influenza H3N2/HK/1/68.
Age, Specimen part
View SamplesPurpose: Aim of the study is to identify changes in hepatic gene expression induced by either a 40kcal% coconut oil rich high fat diet (HFD), a 40kcal% soybean oil plus coconut oil high fat diet (SO-HFD) or a low fat vivarium chow diet (Viv). Methods: Livers from mice that had been fed one of the above mentioned diets for 35 weeks, were used to make cDNA libraries that were then sent for deep sequencing, using the Illumina TruSeq RNA. Result: Many genes involved in metabolism, lipid binding, transport and storage and many Cyp genes are dysregulated in the two high fat diets as compared to Viv HFDs in SO-HFD mice. Comparing the two HFDs shows more metabolism and disease related genes dysregulated in SO-HFD vs HFD. Conclusion: A diet high in soybean oil may be more detrimental to metabolic health than a diet high in saturated fats. Overall design: cDNA isolated from livers from mice fed HFD, SO-HFD or Viv for 35 weeks, were 50bp pair-ended sequenced in triplicate using Illumina TruSeq RNA Sample Prep v2 Kit.
Soybean Oil Is More Obesogenic and Diabetogenic than Coconut Oil and Fructose in Mouse: Potential Role for the Liver.
No sample metadata fields
View SamplesTo study the role of hepatic nuclear factor alpha (HNF4a in hepatogenesis, we used loxP-Cre technology to eliminate it from developing mouse livers.
Hepatocyte nuclear factor 4alpha orchestrates expression of cell adhesion proteins during the epithelial transformation of the developing liver.
Specimen part
View SamplesHNF4a is an important liver transcription factor that regulates at least a thousand genes in the liver. Here we used expression profiling in HepG2 cells, a hepatocellular carcinoma cell line, in which HNF4a was knocked down by RNAi to identify some of those target genes. This dataset accompanies the article in Hepatology 2010 Feb;51(2):642-53. Integrated approach for the identification of human hepatocyte nuclear factor 4alpha target genes using protein binding microarrays by Bolotin E, Liao H, Ta TC, Yang C, Hwang-Verslues W, Evans JR, Jiang T, Sladek FM.
Integrated approach for the identification of human hepatocyte nuclear factor 4alpha target genes using protein binding microarrays.
Cell line
View Samples