Identifying the genes underlying quantitative trait loci (QTL) for disease has proven difficult, mainly due to the low resolution of the approach and the complex genetics involved. However, recent advances in bioinformatics and the availability of genetic resources now make it possible to narrow the genetic intervals and test candidate genes. In addition to identifying the causative genes, defining the pathways that are affected by these QTL is of major importance as it can give us insight into the disease process and provide evidence to support candidate genes. In this study we mapped three significant and one suggestive QTL on Chromosomes (Chrs) 1, 4, 15, and 17, respectively, for increased albumin excretion (measured as albumin-to-creatinine ratio) in a cross between the MRL/MpJ and SM/J mouse inbred strains. By combining data from several sources and by utilizing gene expression data, we identified Tlr12 as a likely candidate for the Chr 4 QTL. Through the mapping of 33,881 transcripts measured by microarray on kidney RNA from each of the 173 male F2 animals, we identified several downstream pathways associated with these QTL. Among these were the glycan degradation, leukocyte migration, and antigen presenting pathways. We demonstrate that by combining data from multiple sources, we can identify not only genes that are likely to be causal candidates for QTL, but also the pathways through which these genes act to alter phenotypes. This combined approach provides valuable insights into the causes and consequences of renal disease.
Uncovering genes and regulatory pathways related to urinary albumin excretion.
Sex, Age
View SamplesPurpose: The goal of this study was to map the pathway of mRNA decay by human RNase L Methods: Total RNA was extracted (RNeasy kit, Qiagen). RNA integrity was verified by an RNA 6000 Nano Chip, using BioAnalyzer and 2100 Expert software (Agilent Technologies). The mRNA was enriched by oligo-dT pulldown from total RNA, followed by fragmentation, adapter ligation, PCR amplification, and finally sequencing on Illumina HiSeq 2000 platform. For sequencing introns, the oligo-dT pulldown step was replaced with Ribo-Zero rRNA removal (Illumina). Sequencing reads were mapped to the human genome hg19 using TopHat 2 set to map stranded reads with default parameters. Mapped read counts were obtained using HTseq-count run in union mode. Results: We developed an approach for transcriptome-wide profiling of RNase L activity in human cells and identified hundreds of direct RNA targets and non-targets. We show that this RNase L-dependent decay (RLDD) selectively affects transcripts regulated by miR-17/miR-29/miR-200 and other microRNAs that function as suppressors of mammalian cell adhesion and proliferation. RNase L mimics the effects of these microRNAs and acts as a suppressor of proliferation and adhesion in mammalian cells. Conclusions: Our data suggest that RLDD serves to establish an anti-proliferative state via destabilization of the microRNA-regulated transcriptome. Overall design: Human mRNA profiles from HeLa, T47D and HAP1 cells were generated by deep sequencing using Illumina Illumina HiSeq 2000.
Human RNase L tunes gene expression by selectively destabilizing the microRNA-regulated transcriptome.
No sample metadata fields
View SamplesThe germinal center (GC) is a microanatomical compartment wherein high-affinity antibody-producing B cells are selectively expanded. B cells proliferate and mutate their antibody genes in the dark zone (DZ) of the GC and are then selected by T cells in the light zone (LZ) on the basis of affinity. Here, we show that T cell help regulates the speed of cell cycle phase transitions and DNA replication of GC B cells. Genome sequencing and single-molecule analyses revealed that T cell help shortens S phase by regulating replication fork progression while preserving the relative order of replication origin activation. Thus, high-affinity GC B cells are selected by a mechanism that involves prolonged dwell time in the DZ where selected cells undergo accelerated cell cycles. Overall design: To determine whether GC B cells receiving high levels of T cell help show a specific change in gene expression, we compared DZ cells in the G1 phase of the cell cycle from aDEC-OVA and control aDEC-CS treated GCs using a fluorescent ubiquitination-based cell cycle indicator (Fucci-tg). RNA sequencing revealed that T cell-mediated selection produced an increase in gene expression programs associated with the cell cycle, metabolism, including the metabolism of nucleotides, and genes downstream of c-Myc and the E2F transcription factors.
HUMORAL IMMUNITY. T cell help controls the speed of the cell cycle in germinal center B cells.
No sample metadata fields
View SamplesBulk RNA-seq to profile of c-kit+ cardiac interstitial cells, comparing the transcriptomes of Pim-1 enhanced cardiac progenitor cells and transfection control Overall design: Transcriptional profiling of Pim-1 enhanced human derived cardiac interstitial cells by bulk RNA-Seq
Safety profiling of genetically engineered Pim-1 kinase overexpression for oncogenicity risk in human c-kit+ cardiac interstitial cells.
Specimen part, Subject
View SamplesNearly all colorectal cancers have dysregulated Wnt signalling, predominantly through the mutation of the Apc (Adenomatous Polyposis Coli) gene. Therefore it is of vital importance to elucidate the key Wnt target genes in intestinal cells in vivo. We have used a novel inducible cre-lox based murine system (designated ApcFlox) to investigate the consequences of perturbation of Wnt signalling following inactivation of Apc in vivo within 100% of the intestinal epithelium. We have employed microarray analysis at 3 time points within our ApcFlox system (Day 3 prior to the onset of phenotype, day 4 the establishment of the phenotype and day 5 gross phenotype of altered proliferation, differentiation and migration) and from adenomas arising in the ApcMin/+ background allowing us characterise Wnt/beta-catenin target genes based on their expression profiles during different stages of intestinal tumourigenesis. Furthermore, we have employed microarray analysis using livers from our ApcFlox system and have demonstrated that there is very little overlap in the Wnt target genes induced by Apc loss in the liver and the intestine. More importantly, we have been able to determine a novel set of putative Wnt/beta-catenin target genes which are upregulated at both early and late stages of tumourigenesis in the intestine and may represent novel therapeutic targets in colon cancer.
Hunk/Mak-v is a negative regulator of intestinal cell proliferation.
Specimen part
View SamplesWhole-transcriptome survey of gene expression differences between germ-free (GF) and conventionally raised (CONV-R) mice.
Analysis of gut microbial regulation of host gene expression along the length of the gut and regulation of gut microbial ecology through MyD88.
Specimen part
View SamplesThe intermediate filament protein Nestin serves as a biomarker for stem cells and has been used to identify subsets of cancer stem-like cells. However, the mechanistic contributions of Nestin to cancer pathogenesis are not understood. Here we report that Nestin binds the hedgehog pathway transcription factor Gli3 to mediate the development of medulloblastomas of the hedgehog subtype. In a mouse model system, Nestin levels increased progressively during medulloblastoma formation resulting in enhanced tumor growth. Conversely, loss of Nestin dramatically inhibited proliferation and promoted differentiation. Mechanistic investigations revealed that the tumor-promoting effects of Nestin were mediated by binding to Gli3, a zinc finger transcription factor that negatively regulates hedgehog signaling. Nestin binding to Gli3 blocked Gli3 phosphorylation and its subsequent proteolytic processing, thereby abrogating its ability to negatively regulate the hedgehog pathway. Our findings show how Nestin drives hedgehog pathway-driven cancers and uncover in Gli3 a therapeutic target to treat these malignancies.
Nestin Mediates Hedgehog Pathway Tumorigenesis.
Specimen part
View SamplesmRNA regulation by the circadian protein Nocturnin in A549 cells. Overall design: Total RNA from WT and NOCT KO A549 cells were subject to poly-A pulldown and RNA-seq.
The metabolites NADP<sup>+</sup> and NADPH are the targets of the circadian protein Nocturnin (Curled).
Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Identification of TDRD1 as a direct target gene of ERG in primary prostate cancer.
Cell line
View SamplesERG overexpression is the most frequent molecular alteration in prostate cancer. We analyzed different stages of prostate cancer to identify genes that were coexpressed with ERG overexpression. In primary prostate tumors, it was shown that TDRD1 expression was the strongest correlated gene with ERG overexpression and we suggest TDRD1 as a direct ERG target gene.
Identification of TDRD1 as a direct target gene of ERG in primary prostate cancer.
No sample metadata fields
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