The aim was to analyze the transcriptome of different types of preneoplastic colorectal lesions in comparison with that of the corresponding normal mucosa.
Preinvasive colorectal lesion transcriptomes correlate with endoscopic morphology (polypoid vs. nonpolypoid).
Specimen part
View SamplesBackground: Colorectal cancers are believed to arise predominantly from adenomas. Although these precancerous lesions have been subjected to extensive clinical, pathological, and molecular analyses, little is currently known about the global gene expression changes accompanying their formation. Results: To characterize the molecular processes underlying the transformation of normal colonic epithelium, we compared the transcriptomes of 32 prospectively collected adenomas with those of normal mucosa from the same individuals. Important differences emerged not only between the expression profiles of normal and adenomatous tissues, but also between those of small and large adenomas. A key feature of the transformation process was the remodeling of the Wnt pathway reflected in patent over- and underexpression of 78 known components of this signaling cascade. Conclusions: Our transcriptomic profiles of normal colonic mucosa and colorectal adenomas shed new light on the early stages of colorectal tumorigenesis.
Transcriptome profile of human colorectal adenomas.
Specimen part, Subject
View SamplesKidneys were snap frozen from 2 month old wild type, Col4a3-/-, or Col4a3-/-OPN-/- mice. RNA was isolated using Mirvana Paris kit.
Osteopontin deficiency ameliorates Alport pathology by preventing tubular metabolic deficits.
Specimen part
View SamplesLeft ventricular noncompaction (LVNC) Causes prominent ventricular trabeculations and reduces cardiac systolic function. The clinical presentation of LVNC ranges from asymptomatic to heart failure. We show that germline mutations in human MIB1 (mindbomb homolog 1), which encodes an E3 ubiquitin ligase that promotes endocytosis of the NOTCH ligands DELTA and JAGGED, cause LVNC in autosomal-dominant pedigrees, with affected individuals showing reduced NOTCH1 activity and reduced expression of target genes. Functional studies in cells and zebrafish embryos and in silico modeling indicate that MIB1 functions as a dimer, which is disrupted by the human mutations. Targeted inactivation of Mib1 in mouse myocardium causes LVNC, a phenotype mimicked by inactivation of myocardial Jagged1 or endocardial Notch1. Myocardial Mib1 mutants show reduced ventricular Notch1 activity, expansion of compact myocardium to proliferative, immature trabeculae and abnormal expression of cardiac development and disease genes. These results implicate NOTCH signaling in LVNC and indicate that MIB1 mutations arrest chamber myocardium development, preventing trabecular maturation and compaction. Overall design: RNA was isolated from the ventricles of 16 WT and 16 Mib1flox; CTnT-cre hearts at E14.5 and then pooled into four replicates.
Mutations in the NOTCH pathway regulator MIB1 cause left ventricular noncompaction cardiomyopathy.
No sample metadata fields
View SamplesBackground & Aims Hepatocytes differentiated from human embryonic stem cells (hESCs) have the potential to overcome the shortage of primary hepatocytes for clinical use and drug development. Many strategies for this process have been reported, but the functionality of the resulting cells is incomplete. We hypothesize that the functionality of hPSC-derived hepatocytes might be improved by making the differentiation method more similar to normal in vivo hepatic development. Methods We tested combinations of growth factors and small molecules targeting candidate signaling pathways culled from the literature to identify optimal conditions for differentiation of hESCs to hepatocytes, using qRT-PCR for stage-specific markers to identify the best conditions. Immunocytochemistry was then used to validate the selected conditions. Finally, induction of expression of metabolic enzymes in terminally differentiated cells was used to assess the functionality of the hESC-derived hepatocytes. Results Optimal differentiation of hESCs was attained using a 5-stage protocol. After initial induction of definitive endoderm (stage 1), we showed that inhibition of the WNT/ß-catenin pathway during the 2nd and 3rd stages of differentiation was required to specify first posterior foregut, and then hepatic gut cells. In contrast, during the 4th stage of differentiation, we found that activation of the WNT/ß-catenin pathway allowed generation of proliferative bipotent hepatoblasts, which then were efficiently differentiated into hepatocytes in the 5th stage by dual inhibition of TGF-ß and NOTCH signaling. Conclusion Here, we show that stage-specific regulation of the WNT/ß-catenin pathway results in improved differentiation of hESCs to functional hepatocytes. Overall design: mRNA profiles of undifferentiated, definitive endoderm, stage 2-5 cell ines were generated by deep sequencing, in duplicate, as well as five liver samples.
Stage-specific regulation of the WNT/β-catenin pathway enhances differentiation of hESCs into hepatocytes.
Specimen part, Subject
View SamplesRibsome profiling analysis of mRNA translation in mouse cells under conditions of mTOR activiation or inhibition. Overall design: embryonic fibroblasts from 4EBP1/2 p53 mutants treated with Torin1
A unifying model for mTORC1-mediated regulation of mRNA translation.
Specimen part, Treatment, Subject
View SamplesAn understanding of the mechanisms regulating white adipose tissue (WAT) formation is key for developing of new tools to treat obesity and its related diseases. Here, we identify DEPTOR as a positive regulator of adipogenesis whose expression is associated with obesity. In a polygenic mouse model of obesity/leanness, Deptor is part of the Fob3a QTL linked to obesity and we fine that Deptor is the highest priority candidate gene regulating WAT accumulation in this model. Using a doxycycline-inducible mouse model for Deptor overexpression, we confirmed that Deptor promotes WAT expansion in vivo. DEPTOR expression is elevated in WAT of obese humans and strongly correlates with the degree of obesity. We show that DEPTOR is induced during adipogenesis and that its overexpression cell-autonomously promotes, while its suppression blocks, adipogenesis. DEPTOR positively regulates adipogenesis by promoting the activity of the pro-adipogenic factors Akt/PKB and PPAR-gamma. These results establish DEPTOR as a physiological regulator of adipogenesis and provide new insights into the molecular mechanisms controlling WAT formation.
DEPTOR cell-autonomously promotes adipogenesis, and its expression is associated with obesity.
Sex, Specimen part
View SamplesThe potential safety issues related to the acquisition of common genomic aberrations in hPSC cultures are well-recognized, but these risks have not been evaluated for sporadic mutations. Here, we explore whether a sporadic mutation that spontaneously arose in a hESC culture consisting of a single-copy deletion of chr17p13.1 would confer a survival advantage to the mutant cells. Compared to wild-type cells with two normal copies of the chr17p13.1 region, the mutant cells displayed a selective advantage when exposed to stressful conditions, and retained a higher percentage of pluripotent cells after two weeks of in vitro differentiation. Knockdown of TP53, which is a gene encompassed by the deleted region, in wild-type cells mimicked the chr17p13.1 deletion phenotype. RNA sequencing analysis showed differential expression of genes in pathways related to proliferation and differentiation. Thus, phenotypic implications of sporadic mutations must be taken into consideration before using the hPSC for clinical applications. Overall design: Triplicate cDNA libraries of two mutant WA09 lines with a single-copy deletion of chr17p13.1, and two wild-type WA09 lines, for a total of 12 libraries were sequenced using Illumina HiSeq 2500. The sequence reads were mapped to hg19 reference genome and hits that passed quality filters were analyzed for differential expression.
Spontaneous Single-Copy Loss of TP53 in Human Embryonic Stem Cells Markedly Increases Cell Proliferation and Survival.
No sample metadata fields
View SamplesTranscription is a highly regulated process, and stress-induced changes in gene transcription have been shown to play a major role in responses and adaptation to stress. Numerous emerging genome-wide studies reveal prevalent transcription beyond known protein-coding gene loci, generating a variety of new classes of RNAs, most of unknown function. One such class, termed downstream of gene (DoG)-containing transcripts, was reported to result from transcriptional readthrough upon osmotic stress in human cell lines. However, how widespread the readthrough phenomenon is, and what its causes and consequences are, remain elusive. Here we present a systematic genome-wide mapping of transcriptional readthrough, using deep nuclear RNA-seq, comparing heat shock, osmotic and oxidative stress in NIH3T3 mouse fibroblast cells. We observe massive induction of transcriptional readthrough under all stress conditions, with significant, yet not complete overlap of readthrough-induced loci between different conditions. Importantly, our analyses suggest that stress-induced transcriptional readthrough is not a random failure process, but is rather differentially induced across different conditions. Additionally, analyzing public Pol-II occupancy data further supported our findings of stress-induced readthrough. We explore potential regulators and find a role for HSF1 in the induction of a subset of heat shock-induced readthrough transcripts. Furthermore, we examine genomic features of readthrough transcription, and observe a unique chromatin signature typical of DoG-producing regions, suggesting that readthrough transcription is associated with the maintenance of an open chromatin state. Overall design: RNA profiles of NIH3T3 (mouse embryonic fibroblasts) cells after three stress treatments and control were generated by deep sequencing, in two replicates using Illumina HiSeq 2000.
Comparative analysis reveals genomic features of stress-induced transcriptional readthrough.
Specimen part, Cell line, Subject
View SamplesWe report single-cell transcriptional assessment and functional circuit characterization of neuron types within the mouse entopeduncular nucleus (EP) Overall design: Transcriptional profilingof EP neurons from P60-70 C57BL/6 male mice; three types were identified, characterized, and incorporated into a synaptic-circuit model of basal ganglia please note that Replicate 2 was lost experimentally and not included, so n=3 replicates total
Genetically Distinct Parallel Pathways in the Entopeduncular Nucleus for Limbic and Sensorimotor Output of the Basal Ganglia.
Sex, Specimen part, Cell line, Subject
View Samples