A fundamental challenge in genomics is to map DNA sequence variants onto changes in gene expression. Gene expression is regulated by cis-regulatory elements (CREs, i.e., enhancers, promoters, and silencers) and the trans factors (e.g., transcription factors) that act upon them. A powerful approach to dissecting cis and trans effects is to compare F1 hybrids with F0 homozygotes. Using this approach and taking advantage of the high frequency of polymorphisms in wild-derived inbred Cast/EiJ mice relative to the reference strain C57BL/6J, we conducted allele-specific mRNA-seq analysis in the adult mouse retina, a disease-relevant neural tissue. We found that cis effects account for the bulk of gene regulatory divergence in the retina. Many CREs contained functional (i.e., activating or silencing) cis-regulatory variants mapping onto altered expression of genes, including genes associated with retinal disease. By comparing our retinal data with previously published liver data, we found that most of the cis effects identified were tissue-specific. Lastly, by comparing reciprocal F1 hybrids, we identified evidence of imprinting in the retina for the first time. Our study provides a framework and resource for mapping cis-regulatory variants onto changes in gene expression, and underscores the importance of studying cis-regulatory variants in the context of retinal disease. Overall design: Retinas from four classes of 8 week old male mice were collected: F0 C57BL/6J (B6), F0 Cast/EiJ (Cast), F1 B6xCast, and F1 CastxB6. Three replicates per class were generated. Each replicate consisted of a pool of 6-8 retinas. The mRNA-seq was conducted with paired-end 2x101 sequencing on the Illumina HiSeq 2000 platform. One lane of sequencing was run for all twelve samples. An additional lane of sequencing was run for the six F1 samples.
Hybrid mice reveal parent-of-origin and Cis- and trans-regulatory effects in the retina.
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View SamplesBacterial genotoxins, produced by several Gram-negative bacteria, induce DNA damage in the target cells. While the responses induced in the host cells have been extensively studied in vitro, the role of the genotoxins as effectors during the course of acute and chronic infections remains poorly characterized.To address this issue, we assessed the effects of the Salmonella enterica genotoxin, known as typhoid toxin, in in vivo models of murine chronic infections. Immunocompetent mice were chronically infected with isogenic S. enterica, serovar Typhimurium (S. Typhimurium) strains, encoding either a functional (MC71-TT) or an inactive (MC71-DcdtB) typhoid toxin.
The Typhoid Toxin Promotes Host Survival and the Establishment of a Persistent Asymptomatic Infection.
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View SamplesThe rapid development in septic patients of features of marked immunosuppression associated with increased risk of nosocomial infections and mortality represents the rational for the initiation of immune targeted treatments in sepsis. However, as there is no clinical sign of immune dysfunctions, the current challenge is to develop biomarkers that will help clinicians identify the patients that would benefit from immunotherapy and monitor its efficacy. Using an in vitro model of endotoxin tolerance (ET), a pivotal feature of sepsis-induced immunosuppression in monocytes, we identified using gene expression profiling by microarray a panel of transcripts associated with the development of ET which expression was restored after immunostimulation with interferon-gamma (IFN-). These results were confirmed by qRT-PCR. Importantly, this short-list of markers was further evaluated in patients. Of these transcripts, six (TNFAIP6, FCN1, CXCL10, GBP1, CXCL5 and PID1) were differentially expressed in septic shock patients blood compared to healthy blood upon ex vivo LPS stimulation and were restored by IFN-. In this study, by combining a microarray approach in an in vitro model and a validation in clinical samples, we identified a panel of six transcripts that could be used for the identification of septic patients eligible for IFNg therapy. The potential value of these markers should now be evaluated in a larger cohort of patients. Upon favorable results, they could serve as stratification tools prior to immunostimulatory treatment and to monitor drug efficacy.
Identification of biomarkers of response to IFNg during endotoxin tolerance: application to septic shock.
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View SamplesCancer cachexia syndrome is observed in 80% of patients with advanced-stage cancer, and it is one of the most frequent causes of death. Severe wasting accounts for more than 80% in patients with advanced pancreatic cancer. Here we wanted to define, by using an microarray approach and the Pdx1-cre;LSL-KrasG12D;INK4a/arffl/fl, the pathways involved in muscle, liver and white adipose tissue wasting.
Pancreatic cancer-induced cachexia is Jak2-dependent in mice.
Age, Specimen part, Disease, Disease stage
View SamplesMost hepatocellular carcinomas in younger patients from Peru arise from non-cirrhotic livers. Histological examination of the non-tumor liver tissues highlights the presence of clear cell foci in a significant fraction of Peruvian patients with hepatocellular carcinoma.
Liver clear cell foci and viral infection are associated with non-cirrhotic, non-fibrolamellar hepatocellular carcinoma in young patients from South America.
Specimen part, Disease stage, Subject
View SamplesDespite widespread use of sunscreens that minimize erythema by blocking ultraviolet B (UVB) radiation, incidence rates of melanoma continue to rise. In considering this disparity between intervention and disease prevalence, we investigated the in vivo transcriptome of human skin treated with sunscreen and solar-simulated radiation (ssR). A focal skin area of healthy participants was exposed to ssR at 1 minimal erythema dose (MED), 0.1 MED or 100 J/m2 with or without prior application of sunscreen, or to non-UVB-spectrum of ssR (solar-simulated UVA/visible/infrared radiation: ssA). Skin biopsies were analyzed using expression microarrays.
Transcriptional signatures of full-spectrum and non-UVB-spectrum solar irradiation in human skin.
Sex, Specimen part
View SamplesHigh expression of the ETS family transcription factor ERG is associated with poor clinical outcome in acute myeloid leukemia (AML) and acute T-cell lymphoblastic leukemia (T-ALL). In murine models, high ERG expression induces both T-ALL and AML. However, no study to date has defined the effect of high ERG expression on primary human hematopoietic cells. In the present study, human CD34+ cells were transduced with retroviral vectors to elevate ERG gene expression to levels detected in high ERG AML. RNA sequencing was performed on purified populations of transduced cells to define the effects of high ERG on gene expression in human CD34+ cells. Integration of the genome-wide expression data with other data sets revealed that high ERG drives an expression signature that shares features of normal hematopoietic stem cells, high ERG AMLs, early T-cell precursor-ALLs and leukemic stem cell signatures associated with poor clinical outcome. Functional assays linked this gene expression profile to enhanced progenitor cell expansion. These results support a model whereby a stem cell gene expression network driven by high ERG in human cells enhances the expansion of the progenitor pool, providing opportunity for the acquisition and propagation of mutations and the development of leukemia. Overall design: RNA sequencing in ERG overexpressing human CD34+ cells
Overexpression of ERG in cord blood progenitors promotes expansion and recapitulates molecular signatures of high ERG leukemias.
No sample metadata fields
View SamplesA major impediment to the effective treatment of patients with PDAC (Pancreatic Ductal Adenocarcinoma) is the molecular heterogeneity of the disease, which is reflected in an equally diverse pattern of clinical responses to therapy. We developed an efficient strategy in which PDAC samples from 17 consecutively patients were obtained by EUS-FNA or surgery, their cells maintained as a primary culture and tumors as breathing tumors by xenografting in immunosuppressed mice. For these patients a clinical follow up was obtained. On the breathing tumors we studied the RNA expression profile by an Affymetrix approach. We observed a significant heterogeneity in their RNA expression profile, however, the transcriptome was able to discriminate patients with long- or short-time survival which correspond to moderately- or poorly-differentiated PDAC tumors respectively. Cells allowed us the possibility to analyze their relative sensitivity to several anticancer drugs in vitro by developing a chimiogram, like an antibiogram for microorganisms, with several anticancer drugs for obtaining an individual profile of drug sensitivity and as expected, the response was patient-dependent. Interestingly, using this approach, we also found that the transcriptome analysis could predict the sensitivity to some anticancer drugs of patients with a PDAC. In conclusion, using this approach, we found that the transcriptome analysis could predict the sensitivity to some anticancer drugs and the clinical outcome of patients with a PDAC.
Transcriptomic analysis predicts survival and sensitivity to anticancer drugs of patients with a pancreatic adenocarcinoma.
Sex, Age, Specimen part
View SamplesEfferent inhibition of cochlear outer hair cells is mediated by nicotinic cholinergic receptors containing alpha9 (a9) and alpha10 subunits. Mice lacking a9 nicotinic subunits fail to exhibit classic olivocochlear responses and are characterized by abnormal synaptic morphology at the base of outer hair cells. To detail molecular changes induced upon the loss of a9 subunit, we sampled cochlear RNA from wild type and a9 null mice at postnatal (P) days spanning periods of synapse formation and maturation (P3, P7, P13 and P60). Our findings point to a delay in cochlear maturation starting at the onset of hearing (P13), as well as an up-regulation of various GABA receptor subunits in adult mice lacking the a9 nicotinic subunit.
Lack of nAChR activity depresses cochlear maturation and up-regulates GABA system components: temporal profiling of gene expression in alpha9 null mice.
Specimen part
View SamplesThe goals of this study is to test whether NICD presence protects the RBPjk-null Hair Follicles by altering gene expression via association with other DNA binding proteins at P3, just before the conversion to TSLP-producing keratin cysts. Overall design: Methods: Skin samples were embedded in OCT. Sectioned at 20µm thickness. Dehydrated in EtOH, and equilibrated to Xylene before the LCM procedure. Laser capture was performed with Arcturus Veritas. Methods: ~100 hair follicles from Notch-null, PS-null, RBPjk-null and wild-type samples were pooled into 3 biological replicates for each genotype and subjected to RNA isolation followed by RNA-Seq. Conclusions: A total of 2047 genes were differentially expressed (=1.5 fold) in three or more biological replicates of Notch mutant hair follicles compared to wild-type controls (p-value<0.05). Unsupervised hierarchical clustering analysis failed to distinguish between the mutants.
The Notch Intracellular Domain Has an RBPj-Independent Role during Mouse Hair Follicular Development.
Cell line, Subject
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