Choroid plexuses (CP) develop early during development. They form a barrier between the blood and the cerebrospinal fluid, and fulfill important protective and nutritive functions. We used Affymetrix microarrays to assess whether CP of the lateral ventricles (LVCP) have similar functions in developing and adult brain. We identified distinct families of protective and transport genes and found that most of these genes were already well expressed during development.
Developmental changes in the transcriptome of the rat choroid plexus in relation to neuroprotection.
Specimen part
View SamplesCholecystokinin (CCK) is a satiety hormone produced by discrete enteroendocrine cells scattered among absorptive cells of the small intestine. CCK is released into blood following a meal; however, the mechanisms inducing hormone secretion are largely unknown. Ingested fat is the major stimulant of CCK secretion. We recently identified a novel member of the lipoprotein remnant receptor family known as immunoglobulin-like domain containing receptor 1 (ILDR1) in intestinal CCK cells and postulated that this receptor conveyed the signal for fat-stimulated CCK secretion. In the intestine, ILDR1 is expressed exclusively in CCK cells. Orogastric administration of fatty acids elevated blood levels of CCK in wild type but not ILDR1-deficient mice, although the CCK secretory response to trypsin inhibitor was retained. The uptake of fluorescently labeled lipoproteins in ILDR1-transfected CHO cells and release of CCK from isolated intestinal cells required a unique combination of fatty acid plus HDL. CCK secretion secondary to ILDR1 activation is associated with increased [Ca2+]i consistent with regulated hormone release. These findings demonstrate that ILDR1 regulates CCK release through a mechanism dependent on fatty acids and lipoproteins and that absorbed fatty acids regulate gastrointestinal hormone secretion.
Immunoglobulin-like domain containing receptor 1 mediates fat-stimulated cholecystokinin secretion.
Specimen part
View SamplesPurpose: RNA editing by ADAR1 is essential for hematopoietic development. The goals of this study were firstly, to identify ADAR1-specific RNA-editing sites by indentifying A-to-I (G) mismatches in RNA-seq data compared to mm9 reference genome in wild type mice that were not edited or reduced in editing frequency in ADAR1E861A editing deficient mice. Secondly, to determine the transcriptional consequence of an absence of ADAR1-mediated A-to-I editing. Methods: Fetal liver mRNA profiles of embryonic day 12.5 wild-type (WT) and ADAR1 editing-deficient (ADAR1E861A) mice were generated by RNA sequencing, in triplicate (biological replicates), using Illumina HiSeq2000. The sequence reads that passed quality filters were analyzed at the transcript level with TopHat followed by Cufflinks. qRT–PCR validation was performed using SYBR Green assays. A-to-I (G) RNA editing sites were identified as previously described by Ramaswami G. et al., Nature Methods, 2012 using Burrows–Wheeler Aligner (BWA) followed by ANOVA (ANOVA). RNA editing sites were confirmed by Sanger sequencing. Results: Using an optimized data analysis workflow, we mapped about 30 million sequence reads per sample to the mouse genome (build mm9) and identified 14,484 transcripts in the fetal livers of WT and ADAR1E861A mice with BWA. RNA-seq data had a goodness of fit (R2) of >0.94 between biological triplicates per genotype. Approximately 4.4% of the transcripts showed differential expression between the WT and ADAR1E861A fetal liver, with a LogFC=1.5 and p value <0.05. A profound upregulation of interferon stimulated genes were found to be massively upregulated (up to 11 logFC) in ADAR1E861A fetal liver compared to WT. 6,012 A-to-I RNA editing sites were identified when assessing mismatches in RNA-seq data of WT and ADAR1E861A fetal liver. Conclusions: Our study represents the first detailed analysis of fetal liver transcriptomes and A-to-I RNA editing sites, with biologic replicates, generated by RNA-seq technology. A-to-I RNA editing is the essential function of ADAR1 and is required to suppress interferon signaling to endogenous RNA. Overall design: Fetal liver mRNA profiles of E12.5 wild type (WT) and ADAR E861A mutant mice were generated by deep sequencing, in triplicate, using Illumina HiSeq 200.
RNA editing by ADAR1 prevents MDA5 sensing of endogenous dsRNA as nonself.
No sample metadata fields
View SamplesAdenosine-to-Inosine (A-to-I) editing of dsRNA by ADAR proteins is a pervasive feature of the epitranscriptome. There are estimated to be over 100 million potential A-to-I editing sites in humans and A-to-I editing can have varying consequences for gene expression. Whilst editing resulting in protein recoding defines the role of ADAR2, ADAR1 has been proposed to have both editing-dependent and -independent functions. The relative contribution of these putative functions to ADAR1 biology is unclear. We demonstrate that the absence of ADAR1-mediated editing is well tolerated when the cytosolic dsRNA sensor MDA5 is deleted. These mice have normal hematopoiesis, tissue patterning and life span. A direct comparison of the complete deletion of ADAR1 and the specific loss of A-to-I editing activity demonstrates that RNA editing is the only essential function of ADAR1 in adult mice. Therefore, preventing MDA5 substrate formation by endogenous RNA is the essential in vivo function of ADAR1-mediated editing. Overall design: Microfluidics-based multiplex PCR and deep sequencing (mmPCR-seq) identification of A-to-I editing sites in 8 tissues from 12 week old mice in a E861A point mutant of ADAR on a MDA5 knockout background
Protein recoding by ADAR1-mediated RNA editing is not essential for normal development and homeostasis.
Sex, Age, Specimen part, Cell line, Subject
View SamplesAdenosine-to-Inosine (A-to-I) editing of dsRNA by ADAR proteins is a pervasive feature of the epitranscriptome. There are estimated to be over 100 million potential A-to-I editing sites in humans and A-to-I editing can have varying consequences for gene expression. Whilst editing resulting in protein recoding defines the role of ADAR2, ADAR1 has been proposed to have both editing-dependent and -independent functions. The relative contribution of these putative functions to ADAR1 biology is unclear. We demonstrate that the absence of ADAR1-mediated editing is well tolerated when the cytosolic dsRNA sensor MDA5 is deleted. These mice have normal hematopoiesis, tissue patterning and life span. A direct comparison of the complete deletion of ADAR1 and the specific loss of A-to-I editing activity demonstrates that RNA editing is the only essential function of ADAR1 in adult mice. Therefore, preventing MDA5 substrate formation by endogenous RNA is the essential in vivo function of ADAR1-mediated editing. Overall design: RNAseq of Feotal Brain in a E861A point mutant of ADAR on a MDA5 knockout background generated by deep sequencing, in triplicate using Illumina NextSeq500
Protein recoding by ADAR1-mediated RNA editing is not essential for normal development and homeostasis.
Sex, Age, Specimen part, Cell line, Subject
View SamplesThe canonical Wnt signaling pathway is critical for myogenesis and can induce muscle progenitors to switch from proliferation to differentiation; how Wnt signals integrate with muscle specific regulatory factors in this process is poorly understood. We previously demonstrated that the Barx2 homeobox protein promotes differentiation in cooperation with the muscle regulatory factor (MRF) MyoD. Pax7, another important muscle homeobox factor represses differentiation. We now identify Barx2,MyoD,and Pax7 as novel components of the Wnt effector complex, providing a new molecular pathway for regulation of muscle progenitor differentiation. Canonical Wnt signaling induces Barx2 expression in muscle progenitors and perturbation of Barx2 leads to misregulation of Wnt target genes. Barx2 activates two endogenous Wnt target promoters as well as the Wnt reporter gene TOPflash, the latter synergistically with MyoD. Moreover, Barx2 interacts with the core Wnt effectors ß-catenin and TCF, is recruited to TCF/LEF sites, and promotes recruitment of ß-catenin. In contrast, Pax7 represses the Wnt reporter gene and antagonizes the activating effect of Barx2. Pax7 also binds ß-catenin suggesting that Barx2 and Pax7 may compete for interaction with the core Wnt effector complex. Overall, the data show for the first time that Barx2, Pax7, and MRFs can act as direct transcriptional effectors of Wnt signals in myoblasts and that Barx2 and Wnt signaling participate in a regulatory loop. We propose that antagonism between Barx2 and Pax7 in regulation of Wnt signaling may help mediate the switch from myoblast proliferation to differentiation. Overall design: RNA-Seq analyses was used to characterize gene expression in primary myoblasts from wild-type and Barx2 knockout mice.
Barx2 and Pax7 have antagonistic functions in regulation of wnt signaling and satellite cell differentiation.
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View SamplesExpression analysis from two genetically engineered mouse models of osteosarcoma determine the expression profile of mouse osteosarcoma Human osteosarcoma (OS) is comprised of three different subtypes: fibroblastic, chondroblastic and osteoblastic. We previously generated a mouse model of fibroblastic OS by conditional deletion of p53 and Rb in osteoblasts. Here we report an accurate mouse model of the osteoblastic subtype using shRNA-based suppression of p53. Like human OS, tumors frequently present in the long bones and preferentially disseminate to the lungs; features less consistently modeled using Cre:lox approaches. Our approach allowed direct comparison of the in vivo consequences of targeting the same genetic drivers using different technology. This demonstrated that the effects of Cre:lox and shRNA mediated knock-down are qualitatively different, at least in the context of osteosarcoma. Through the use of complementary genetic modification strategies we have established a model of a distinct clinical subtype of OS that was not previously represented and more fully recapitulated the clinical spectrum of this human tumor.
Modeling distinct osteosarcoma subtypes in vivo using Cre:lox and lineage-restricted transgenic shRNA.
Specimen part
View SamplesEstrogen-related receptor ? (ERR?) signaling increases during the neonatal to adult transition in pancreatic islet ß-cells. We show that ß-cell-specific ERR?-deficient (ßERR?KO) mice exhibit glucose intolerance with reduced glucose-stimulated insulin secretion (GSIS) and ßERR?KO islets have defective GSIS function accompanied by changes in genes that regulate ATP biosynthesis, oxidative phosphorylation, and the electron transport chain. ERR? overexpression enhances genes involved in mitochondrial metabolism, resulting in transformation of ß-like-cells into metabolically functional ß-cells that can ameliorate STZ-induced hyperglycemia in NOD-SCID mice. These results suggest that ERR? signaling is essential for the metabolic maturation of ß-like-cells and thus represents a novel therapeutic target in the treatment of diabetes.
ERRγ Is Required for the Metabolic Maturation of Therapeutically Functional Glucose-Responsive β Cells.
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View SamplesWe characterized the effect of loss of ERR expression in mouse pancreatic islets using adenoviral constructs.
ERRγ Is Required for the Metabolic Maturation of Therapeutically Functional Glucose-Responsive β Cells.
Specimen part
View SamplesWe show that ERR? overexpression in ß-like-cells differentiated from human iPSCs enhances genes involved in mitochondrial metabolism, resulting in transformation of these cells into metabolically functional ß-cells that can ameliorate STZ-induced hyperglycemia in NOD-SCID mice. These results suggest that ERR? signaling is essential for the metabolic maturation of ß-like-cells and thus represents a novel therapeutic target in the treatment of diabetes.
ERRγ Is Required for the Metabolic Maturation of Therapeutically Functional Glucose-Responsive β Cells.
No sample metadata fields
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