We describe a novel quantitative cDNA expression profiling strategy, involving amplification of the majority of mouse transcriptome using a defined set of 44 heptamer primers. The amplification protocol allows for efficient amplification from as low as 50pg of mRNA and did not alter the expression of the transcripts even with 200 fold dilution of the minimum requirement of the starting material (10ng of mRNA) for standard RNA-seq protocols. We implemented our methodology on embryological lineage segregation, achieved by graded activation of Activin A/TGFß signaling in mouse embryonic stem cells (mESCs). The fold changes in transcript expression were in excellent agreement with quantitative RT-PCR and we observed a dynamic range spanning more than five orders of magnitude in RNA concentration with a reliable estimation of low abundant transcripts. Our transcriptome data identified key lineage markers, while the high sensitivity showed that novel lineage specific transcripts anticipate the differentiation of specific cell types. We compared our strategy with Std. RNA-seq (Mortazavi et al. 2008) and SMART-seq (Ramsköld et al. 2012). We also showed potential of our methodology to suppress the representation of highly expressing ribosomal transcripts. Overall design: Sequencing was performed on day 4 differentiating mouse ESCs treated for two days with 3 different dosages of Activin A (3ng/mL, 15ng/mL and 100ng/mL). The cells were also treated with SB-431542. Serial dilutions of mRNA derived Activin A(3ng/mL) samples were used to detemine the minimum amount of mRNA required to construct relaible sequencing library. SMARTseq libraries were prepared for both Activin A(3ng/mL) and Activin A(100ng/mL) samples. Three Different primer sets were designed to suppress the representaiton of Ribosomal transcripts.
Quantitative transcriptomics using designed primer-based amplification.
Specimen part, Treatment
View SamplesTranscriptomics data obtained from limiting amounts of mRNA is often noisy, providing primarily qualitative changes in transcript expressions. So far, technical variations arising out of the library preparation protocols have not been adequately characterized at reduced levels of mRNA. Here, we generated sequencing libraries from limiting amounts of mRNA using three amplification-based methods, viz. Smart-seq, DP-seq and CEL-seq, and demonstrated significant technical variations in these libraries. Reduction in mRNA levels led to inefficient amplification of the majority of low to moderately expressed transcripts. Furthermore, stochasticity in primer hybridization and/or enzyme incorporation was magnified during the amplification step resulting in significant distortions in fold changes of the transcripts. Consequently, the majority of the differentially expressed transcripts identified were either high-expressed and/or exhibited high fold changes. High technical variations, which were sequencing depth independent, ultimately masked subtle biological differences mandating the development of improved amplification-based strategies for quantitative transcriptomics from limiting amounts of mRNA. Overall design: Sequencing libraries were prepared from serial dilutions of mRNA, ranging from 1 ng to 25 pg, using three amplification-based methods, viz. Smart-seq, DP-seq and CEL-seq. The mRNA was derived from an in vitro model of lineage segregation achieved by modulating TGF beta signaling pathway in differentiating mouse embryonic stem cells.
Technical variations in low-input RNA-seq methodologies.
Specimen part, Subject
View SamplesIn this study, we confirmed that transformed dedifferentiated astrocytes and neurons acquired a stem/progenitor cell state, although they still retained gene expression memory from their parental cell-type. Transcriptional network analysis on transformed cells revealed up-regulation of genes involved in three signaling pathways: Wnt signaling, cell cycle and focal adhesion with the gene Spp1, also known as osteopontin (OPN) serving as a key node connecting these three pathways. Inhibition of OPN blocked the formation of aggregated neurospheres, affected the proliferative capacity of transformed cell-types and reduced the expression levels of neural stem cell markers. Specific inhibition of OPN in murine glioma tumors prolonged mice survival. We conclude that OPN is an important player in dedifferentiation of cells during tumor formation, hence its inhibition can be a therapeutic target for glioblastoma. Overall design: Cortical neurons and astrocytes were derived from 11 days old SynapsinI-Cre and GFAP-Cre mice, respectively. The cells were cultured in their respective media to maintain their identity. These cells were then transduced with HRas-shp53 lentivirus with a transduction efficiency of >90%. The transduced neurons and astrocytes were later switched to neural stem cell media devoid of serum and supplemented with FGF-2 (NSC media). Within one week, these cells became proliferative and aggregated to form free-floating neurospheres. These cells, hereinafter referred to as NSynR53 and AGR53, respectively, were later harvested and mRNA collected for sequencing library generation using DP-seq. To assess the regression of these cells to an undifferentiated state along the differentiation axis, enriched populations of mESC and NSC were also grown in vitro and mRNA obtained from these cells were subjected to sequencing library preparation.
Identification of therapeutic targets for glioblastoma by network analysis.
No sample metadata fields
View SamplesNatural killer T (NKT) cells are important therapeutic targets in various disease models and under clinical trials for cancer patients. However, their function in obesity and type 2 diabetes remains unclear. Our data show that adipose tissues of both mice and humans contain a population of type-1 NKT cells, whose abundance decreases with increased adiposity and insulin resistance. Although loss-of-function of NKT cells had no effect on glucose tolerance in animals with prolonged high-fat diet (HFD) feeding, activation of NKT cells by lipid agonist -galactosylceramide (GalCer) enhances alternative macrophage polarization in adipose tissue and improves glucose homeostasis in animals at different stages of obesity. Furthermore, the effect of NKT cells is largely mediated by the IL-4/STAT6 signaling axis in obese adipose tissue. Thus, our data identifies a novel therapeutic target for the treatment of obesity-associated inflammation and type-2 diabetes.
Activation of natural killer T cells promotes M2 Macrophage polarization in adipose tissue and improves systemic glucose tolerance via interleukin-4 (IL-4)/STAT6 protein signaling axis in obesity.
Sex, Age, Specimen part
View SamplesAim of this experiment was to look at the gene expression differences in the benzyladenine-treated and untreated Arabidopsis seedlings grown in light
Identification of cytokinin-responsive genes using microarray meta-analysis and RNA-Seq in Arabidopsis.
Age, Specimen part, Compound
View SamplesAim was to look at the gene profile changes in 10 days old Arabidopsis seedlings grown in light and treated with either Zeatin or BA and compared to non-treatment
Identification of cytokinin-responsive genes using microarray meta-analysis and RNA-Seq in Arabidopsis.
Age, Compound
View SamplesGenome wide gene expression analysis in G9a knockdown myoblasts
G9a promotes proliferation and inhibits cell cycle exit during myogenic differentiation.
Specimen part
View SamplesGjd3-CreEGFP mice is a novel genetic tool to study the structural and molecular signatures of Atrioventricular Node (AVN) at a high resolution. Overall design: Focusing on the cardiac conduction system, we developed and rigorously characterized a geentic tool Gjd3-CreEGFP to perform in-depth analysis of AVN structure and composition. Utilizing this AVN-specific mouse model, we performed scRNA-Seq on neonatal Gjd3-CreEGFP mice to guide our single-cell atlas of the Atrio-ventricular conduction system (AVCS).
Using Gjd3-CreEGFP mice to examine atrioventricular node morphology and composition.
Specimen part, Subject
View SamplesAffymetrix expression analysis was used to validate the role of NPR1 in SA mediated transcription.
Global nucleosome positioning regulates salicylic acid mediated transcription in Arabidopsis thaliana.
Specimen part
View SamplesCD34+ cord blood hematopoietic progenitors were expanded in vitro as previously described (Balan et al., J Immunol, 2014) and then differentiated on a mixed feeder layer of OP9 cells expressing or not the Notch ligand Delta-like 1, with FLT3-L, TPO and IL-7. At the end of the cultures, single live Lin- HLA-DR+ cells were index sorted in 96-well plates containing lysis buffer, and snap frozen. Four putative cell types were sorted according to their expression patterns of key combinations of cell surface markers: putative pDCs, putative cDC1s, putative pre-cDC2s and putative cDC2s. Single cell RNA-sequencing libraries were subsequently generated for 90 single cells and 6 control wells using an adaptation of Smart-Seq2 (Villani et al., Science, 2017). Cells were sequenced at a depth of 1-3M reads/cell. Overall design: A total of 90 single cells and 6 controls from one culture were processed using a protocol adapted from Smart-Seq2 protocol (Villani et al., Science, 2017), which allows for the generation of full-length single cell cDNA, and sequencing libraries were generated using Illumina Nextera XT DNA library preparation kit. A few samples (10) were profiled but excluded from the processed data since they were either bulk (5) or blank (1) control samples or excluded due to QC (4). Therefore, there are 86 samples included here.
Large-Scale Human Dendritic Cell Differentiation Revealing Notch-Dependent Lineage Bifurcation and Heterogeneity.
Specimen part, Subject
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