Background: Progressive neurological dysfunction is a key aspect of human aging. Because of underlying differences in the aging of mice and humans, useful mouse models have been difficult to obtain and study. We have used gene-expression analysis and polymorphism screening to study molecular senescence of the retina and hippocampus in two rare inbred mouse models of accelerated neurological senescence (SAMP8 and SAMP10) that closely mimic human neurological aging, and in a related normal strain (SAMR1) and an unrelated normal strain (C57BL/6J).
Mechanisms of aging in senescence-accelerated mice.
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View SamplesWe tamoxifen treated 8-12 week old mice that had floxed alleles of the following: 1) both Apc alleles (giving rise to Apc truncation/inactivation); 2) both Cdx2 alleles (giving rise to Cdx2 inactivation; 3) one Braf allele, that upon Cre-mediated recombination gives a Braf V600E mutant allele (details below), and 4) the combination of both the Cdx2 alleles and the BrafV600E allele. All four of those groups also had a CDX2P-CreERT2 transgene that expresses Cre recombinase fused to a tamoxifen-regulated fragment of the estrogen receptor ligand binding domain. CreERT2 expression occurs only in tissues where the Cdx2 gene is expressed, which is almost exclusively in adult mouse cecum and colon epithelium. A fifth group of mice had the floxed Cdx2 alleles, but no CDX2P-CreERT2 gene. Treating the mice having CDX2P-CreERT2 with tamoxifen permits the Cre recombinase to enter the cell nucleus and recombine the Apc, Braf, and/or Cdx2 alleles containing loxP sequence elements. Mice were treated with intraperitoneal injection of tamoxifen dissolved in corn oil. Three mice per group were used. The control mice did not develop tumors or any morphological or histological changes in their epithelium, but their colons were used to create the 3 control samples. To obtain the BrafV600E allele we used a genetically engineered mouse line previously described by Dankort et al. (Genes Dev 2007, 21:379-84) that can express the BrafV600E mutant protein following Cre-mediated recombination. The Braf(CA) (Braf-Cre-activated) allele mice carry a gene-targeted allele of Braf, where Braf sequences from exons 15-18 are present in the normal mouse Braf intron 14, followed by a mutated exon 15 (carrying the V600E mutation). The exon 15-18 sequence element is flanked by loxP sites. In the absence of Cre-mediated recombination, the Braf(CA) allele expresses a wild type Braf protein. Following Cre-mediated recombination, the Braf exon 15-18 element is removed, and the Braf(CA) allele then encodes the Braf V600E protein (from the introduced mutated exon 15). RNA was purified from tumor or normal tissue, and targets for Affymetrix arrays were synthesized from the mRNAs. We used Affymetrix Mouse Gene 2.1 ST arrays, which hold 41345 probe-sets, but we largely analyzed just those 25216 probe-sets that were mapped to Entrez gene IDs. Raw data was processed with the Robust Multi-array Average algorithm (RMA). Data is log2-transformed transcript abundance estimates. We fit a one-way ANOVA model to the five groups of samples. We supply a supplementary excel workbook that holds the same data as the data matrix file, but also holds the probe-set annotation at the time we analyzed the data, and some simple statistical calculations, which selects subsets of the probe-sets as differentially expressed between pairs of groups, as well as significant Cdx2-/- by Braf V600E interactions. It also gives the homologous human gene IDs we used for enrichment testing, which were 1-to-1 best homologs according to build 68 of NCBI's Homologene. A second supplementary sheet shows the data we enrichment tested after collapsing to distinct human homologs, joins of the results of tests with GSE4045 data and of tests with TCGA data to the mouse genes, and the intersections of selected genes in those data set with our gene selections in mouse. Consumers should consider obtaining more up-to-date probe-set annotation for the array platform.
BRAF<sup>V600E</sup> cooperates with CDX2 inactivation to promote serrated colorectal tumorigenesis.
Sex, Treatment
View SamplesIn this study, we describe the impact of genetic variation on transcript abundance in an F2 population of Arabidopsis thaliana. The RNA-seq resource generated by this study is suitable for expression quantitative trait locus (eQTL) mapping. From the aligned RNA-seq reads, and available genomic data for each of the parents of the cross, we imputed the genomes of each F2 individual (to allow genetic mapping of RNA abundance traits; briefly, genetic differences in aligned RNA-seq reads were used to impute each F2 genome). Our results show that heritable differences on gene expression can be detected using F2 populations (that is, single F2 plants), and shed light on the control of expression differences among strains of this reference plant. Overall design: 183 samples consisting of single F2 plants of a cross between Arabidopsis thaliana accessions 8230 and 6195 were generated. For each sample, RNA was collected from the aerial shoot at the 9th true leaf stage, and Illumina mRNA-seq libraries were constructed. Using these libraries, 50 bp single end RNA-seq Illumina reads were generated for each sample, and used to quantify gene expresison in each individual. The resulting expression phenotypes are suitable for genetic mapping of the control of gene expression differences in the species.
Epistatic and allelic interactions control expression of ribosomal RNA gene clusters in Arabidopsis thaliana.
Specimen part, Subject
View SamplesWe have developed a microfluidics-based in vitro model of the human gut allowing co-culture of human and microbial cells and subsequent multi-omic assessment of the effect of the co-culture on the host transcriptome.
A microfluidics-based in vitro model of the gastrointestinal human-microbe interface.
Specimen part, Treatment
View SamplesInfiltrating monocyte derived macrophages (MDMs) and resident microglia dominate CNS injury sites. We show that MDMs and microglia can directly communicate to modulate each others function. Also, the presence of MDMs in CNS injury suppresses microglia-mediated phagocytosis and inflammation. We suggest that macrophages infiltrating the injured CNS provide a mechanism to control acute and chronic microglia-mediated inflammation, which could otherwise drive damage in a variety of CNS conditions.
Peripherally derived macrophages modulate microglial function to reduce inflammation after CNS injury.
Sex, Specimen part, Treatment
View SamplesCholine kinase alpha (CHKA) plays a crucial role in the regulation of membrane phospholipid synthesis and has oncogenic properties in vitro. We have analyzed the expression of CHKA in cell lines derived from pancreatic ductal adenocarcinoma (PDAC) and have found increased CHKA expression and a good correlation between protein expression and sensitivity to MN58b, a CHKA inhibitor that reduced cell growth through the induction of apoptosis. Accordingly, CHKA knockdown led to reduced drug sensitivity. In addition, we found that gemcitabine-resistant PDAC cells displayed enhanced sensitivity to CHKA inhibition and, in vitro, MN58b had synergistic effects with gemcitabine, 5-fluorouracil and oxaliplatin, three active drugs in the treatment of PDAC. Using tissue microarrays, CHKA was found to be overexpressed in 90% of pancreatic tumors. While cytoplasmic CHKA did not relate to survival, nuclear CHKA distribution was observed in 43% of samples and was associated with survival, especially among patients with well/moderately differentiated tumors. To identify the mechanisms involved in resistance to CHKA inhibitors, we cultured IMIM-PC-2 cells with continuous incremental concentrations of MN58b and isolated a subline with a 30-fold higher IC50. RNA-Seq analysis identified up-regulation of ABCB1 and ABCB4 multidrug resistance transporters and functional studies confirmed that their up-regulation is the main mechanism involved in resistance. Overall, our findings support the notion that CHKA inhibition merits further attention as a therapeutic option in patients with PDAC. Overall design: RNA profile from parental and MN58b-resistant IMIM-PC-2 were generated by deep sequencing were done in triplicates using illumina GAIIx
Choline Kinase Alpha (CHKα) as a Therapeutic Target in Pancreatic Ductal Adenocarcinoma: Expression, Predictive Value, and Sensitivity to Inhibitors.
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View SamplesCholine kinase a (CHKa) plays a crucial role in the regulation of membrane phospholipid synthesis and has oncogenic properties in vitro. We have analyzed the expression of CHKa in cell lines derived from pancreatic ductal adenocarcinoma (PDAC) and have found increased CHKa expression, associated with differentiation. CHKa protein expression was directly correlated with sensitivity to MN58b, a CHKa inhibitor that reduced cell growth through the induction of apoptosis. Accordingly, CHKa knockdown led to reduced drug sensitivity. In addition, we found that gemcitabine-resistant PDAC cells displayed enhanced sensitivity to CHKa inhibition and, in vitro, MN58b had additive or synergistic effects with gemcitabine, 5-fluorouracil, and oxaliplatin, three active drugs in the treatment of PDAC. Using tissue microarrays, CHKa was found to be overexpressed in 90% of pancreatic tumors. While cytoplasmic CHKa did not relate to survival, nuclear CHKa distribution was observed in 43% of samples and was associated with longer survival, especially among patients with well/moderately differentiated tumors. To identify the mechanisms involved in resistance to CHKa inhibitors, we cultured IMIM-PC-2 cells with increasingly higher concentrations of MN58b and isolated a subline with a 30-fold higher IC50. RNA-Seq analysis identified upregulation of ABCB1 and ABCB4 multidrug resistance transporters, and functional studies confirmed that their upregulation is the main mechanism involved in resistance. Overall, our findings support the notion that CHKa inhibition merits further attention as a therapeutic option in patients with PDAC and that expression levels may predict response. Overall design: RNAseq from parental (IMIM-PC2 cell line)) and MN58b-resistant cells by triplicate
Choline Kinase Alpha (CHKα) as a Therapeutic Target in Pancreatic Ductal Adenocarcinoma: Expression, Predictive Value, and Sensitivity to Inhibitors.
Sex, Specimen part, Cell line, Subject
View SamplesMajor roadblocks to developing effective progesterone receptor (PR)-targeted therapies in breast cancer include the lack of highly-specific PR modulators, a poor understanding of the pro- or anti-tumorigenic networks for PR isoforms and ligands, and an incomplete understanding of the cross talk between PR and estrogen receptor (ER) signaling. Through genomic analyses of xenografts treated with various clinically-relevant ER and PR-targeting drugs, we describe how the activation or inhibition of PR dictates distinct ER and PR chromatin binding and differentially reprograms estrogen signaling, resulting in the segregation of transcriptomes into separate PR agonist and antagonist-mediated groups. These findings address an ongoing controversy regarding the clinical utility of PR agonists and antagonists, alone or in combination with tamoxifen, for breast cancer management. Genomic analyses of the two PR isoforms, PRA and PRB, indicate that these isoforms bind distinct genomic sites and interact with different sets of co-regulators to differentially modulate gene expression as well as pro- or anti-tumorigenic phenotypes. Of the two isoforms, PRA inhibited gene expression and ER chromatin binding significantly more than PRB. Of note, the two isoforms reprogrammed estrogen activity to be either pro or anti-tumorigenic. In concordance to the in-vitro observations, differential gene expression was observed in PRA and PRB-rich patient tumors and importantly, PRA-rich gene signatures had poorer survival outcomes. In support of antiprogestin responsiveness of PRA-rich tumors, gene signatures associated with PR antagonists, but not PR agonists, predicted better survival outcomes. This differential of better patient survival associated with PR antagonists versus PR agonists treatments was further reflected in the higher anti-tumor activity of combination therapies of tamoxifen with PR antagonists and modulators. Knowledge of various determinants of PR action and their interactions with estrogen signaling to differentially modulate breast cancer biology should serve as a guide to the development of biomarkers for patient selection and translation of PR-targeted therapies to the clinic. Overall design: For in-vitro experiments, cells were grown in steroid-deprived RPMI for 48 hours to 80% confluence, before being treated for with the hormones of interest (vehicle, 10 nM estrogen, 10 nM R5020 or both estrogen +R5020). Cells were then fixed with 1% formaldehyde for 10 minutes and the crosslinking was quenched with 0.125 M glycine for 5 minutes. Fixed cells were suspended in ChIP lysis buffer (1 ml 1M Tris pH 8.0; 200 µl 5M NaCl; 1 ml 0.5M EDTA; 1 ml NP-40; 1 g SDS, 0.5 g deoxycholate) and sheared in the Diagenode Biorupter for 20 minutes (30 second cycles). 100 µl of sheared chromatin was removed as input control. A 1:10 dilution of sheared chromatin in ChIP dilution buffer (1.7 ml 1M Tris pH 8.0; 3.3 ml 5M NaCl; 5 ml 10% NP-40; 200 µl 10% SDS; to 100 ml with H2O), 4 µg antibody and 30 µl magnetic DynaBeads were incubated in a rotator at 4oC overnight. Chromatin was immunoprecipitated overnight using anti-ER (Santa Cruz Biotechnology HC-20), anti-PR (in-house made KD68) or rabbit IgG (Santa Cruz Biotechnology SC-2027). Next, the immunoprecipitated chromatin was washed with ChIP wash buffer I (2 ml 1M Tris pH 8.0; 3 ml 5M NaCl; 400 µl 0.5M EDTA; 10 ml 10% NP-40; 1 ml 10% SDS; to 100 ml with H2O), ChIP wash buffer II (2 ml 1M Tris pH 8.0; 10 ml 5M NaCl; 400 µl 0.5M EDTA; 10 ml 10% NP-40; 1 ml 10% SDS; to 100 ml with H2O), ChIP wash buffer III (1 ml 1M Tris pH 8.0; 5 ml of 5M LiCl; 200 µl 0.5M EDTA; 10 ml 10% NP-40; 10 ml 10% deoxycholate; to 100 ml with H2O) and TE (pH 8.0). Elution was performed twice from beads by incubating them with 100 µl ChIP-elution buffer (1% SDS, 0.1 M NaHCO3) at 65oC for 15 minutes each. The eluted protein-DNA complexes were de-crosslinked overnight at 65oC in 200 µM NaCl. After de-crosslinking, the mixture was treated with proteinase K for 45 minutes followed by incubation with RNase A for 30 minutes. Finally, DNA fragments were purified using Qiagen PCR purification kit and reconstituted in 50 µl nuclear-free water. Real time PCR was performed using SYBR green. For ChIP-seq library preparations, libraries were prepared using KapaBiosystems LTP library preparation kit (#KK8232) according to the manufacturer's protocol.
Progesterone receptor isoforms, agonists and antagonists differentially reprogram estrogen signaling.
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View SamplesAnalysis of MCF7 cells transfected with ER mutants (S463P, Y537S and D538G) in phenol-red free, charcoal stripped FBS media and regular DMEM/F12 media. Results provide insight on the gene expression profiles induced by the various ER mutants.
ESR1 ligand-binding domain mutations in hormone-resistant breast cancer.
Cell line
View SamplesImmune cell infiltration in myositis were by examining microarray expression profiles in muscle biopsies from 31 myositis patients and 5 normal controls.
Genomic signatures characterize leukocyte infiltration in myositis muscles.
Sex, Specimen part, Disease, Disease stage
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