Single-cell RNA sequencing (scRNA-seq) offers new possibilities to address biological and medical questions. However, systematic comparisons of the performance of diverse scRNA-seq protocols are lacking. We generated data from 583 mouse embryonic stem cells to evaluate six prominent scRNA-seq methods: CEL-seq2, Drop-seq, MARS-seq, SCRB-seq, Smart-seq and Smart-seq2. While Smart-seq2 detected the most genes per cell and across cells, CEL-seq2, Drop-seq, MARS-seq and SCRB-seq quantified mRNA levels with less amplification noise due to the use of unique molecular identifiers (UMIs). Power simulations at different sequencing depths showed that Drop-seq is more cost-efficient for transcriptome quantification of large numbers of cells, while MARS-seq, SCRB-seq and Smart-seq2 are more efficient when analyzing fewer cells. Our quantitative comparison offers the basis for an informed choice among six prominent scRNA-seq methods and provides a framework for benchmarking further improvements of scRNA-seq protocols. Overall design: J1 mESC in two replicates per library preparation method.
A systematic evaluation of single cell RNA-seq analysis pipelines.
Cell line, Subject
View SamplesBackground Single-cell RNA-sequencing (scRNA-seq) experiments typically analyze hundreds or thousands of cells after amplification of the cDNA. The high throughput is made possible by the early introduction of sample-specific bar codes (BCs), and the amplification bias is alleviated by unique molecular identifiers (UMIs). Thus, the ideal analysis pipeline for scRNA-seq data needs to efficiently tabulate reads according to both BC and UMI. Findings zUMIs is a pipeline that can handle both known and random BCs and also efficiently collapse UMIs, either just for exon mapping reads or for both exon and intron mapping reads. If BC annotation is missing, zUMIs can accurately detect intact cells from the distribution of sequencing reads. Another unique feature of zUMIs is the adaptive downsampling function that facilitates dealing with hugely varying library sizes but also allows the user to evaluate whether the library has been sequenced to saturation. To illustrate the utility of zUMIs, we analyzed a single-nucleus RNA-seq dataset and show that more than 35% of all reads map to introns. Also, we show that these intronic reads are informative about expression levels, significantly increasing the number of detected genes and improving the cluster resolution. Conclusions zUMIs flexibility makes if possible to accommodate data generated with any of the major scRNA-seq protocols that use BCs and UMIs and is the most feature-rich, fast, and user-friendly pipeline to process such scRNA-seq data. Overall design: HEK293T cells were sequenced using the mcSCRB-seq protocol (Bagnoli et al., 2017)
zUMIs - A fast and flexible pipeline to process RNA sequencing data with UMIs.
Cell line, Subject
View SamplesMany library preparation methods are available for gene expression quantification. Here, we sequenced and analysed Universal Human Reference RNA (UHRR) prepared using Smart-Seq2, TruSeq (public data) and a protocol using unique molecular identifiers (UMIs) that all include the ERCC spike-in mRNAs to investigate the effects of amplification bias on expression quantification. Overall design: UHRR 10 and 12 replicates for Smart-seq2 and UMI-seq library preparation methods, respectively.
The impact of amplification on differential expression analyses by RNA-seq.
No sample metadata fields
View SamplesDifferentiation of haematopoietic stem cells followsa hierarchical program of transcription-factor regulated events. Early myeloid cell differentiation is dependent on PU.1 and CEBPA (CCAAT/enhancer binding protein alpha), late myeloid differentiation is orchestrated by CEBPE (CCAAT/enhancer binding protein epsilon). The influence of SWI/SNF (SWItch/Sucrose Non-Fermentable) chromatin remodelling factors as novel master regulators of haematopoietic differentiation is only beginning to be explored. Here, we identified three homozygous loss-of-function mutations in SMARCD2 (SWI/SNF related, matrix associated, actin dependent regulator of chromatin, subfamily d, member 2), a member of the SWI/SNF complex, in three unrelated pedigrees. We find that SMARCD2-deficient hematopoiesis results in dysfunctional neutrophil granulocytes, characterized by specific granule deficiency, myelodysplasia, and an excess of blast cells. We can show that SMARCD2 controls early steps in the differentiation of myeloid-erythroid progenitor cells in mice and zebra fish. In vitro SMARCD2 interacts with the transcription factor CEBPE. Furthermore, we find that SMARCD2 controls expression of neutrophil proteins stored in specific granules and leads to transcriptional and chromatin changes in AML cells. Hence, we identify SMARCD2 as a key factor controlling myelopoiesis and as a potential tumour suppressor in leukemia. Overall design: We analyzed CD45.2+ Lin- Mac+/low Sca1+ cKit+ (LSK) cells from Smarcd2 wild-type, heterozygous and mutant foetal livers in at least 5 replicates Additionally, we analysed three different progenitor populations from Smarcd2 wild-type and homozygous knock-out foetal livers: CD45+Lin-Sca-1-CD177+CD34lowCD16/32 (FCGR)low(MEP) CD45+Lin-Sca-1-CD177+CD34+CD16/32(FCGR)int (CMP) CD45+Lin-Sca-1-CD177+CD34+CD16/32(FCGR)high (GMP)
Chromatin-remodeling factor SMARCD2 regulates transcriptional networks controlling differentiation of neutrophil granulocytes.
Sex, Specimen part, Cell line, Subject
View SamplesWe here show that the niche regulates the quality of the hematopoietic stem cells (HSCs) that are regenerated after transplantation. We find that a reduced level of Wnt5a in the niche regenerates dysfunctional HSCs, which do not successfully engraft secondary recipients. In particular, RNA sequencing shows a dysregulated Zeb1-associated gene expression of multiple genes involved in the small GTPase-dependent actin polymerization pathway. Misexpression of these genes results in reduced ability to direct polarized F-actin localization, leading to defects in adhesion, migratory behavior and homing to the bone marrow of secondary recipients. Our study further shows that the Wnt5a-haploinsufficient environment similarly affects BCR-ABLp185+ cells, which, in 42% of the studied recipients, fail to generate leukemia and, in the remaining cases, fail to transfer leukemia to secondary hosts. Thus, we show that Wnt5a in the niche is required to regenerate HSCs and leukemic cells with functional ability to rearrange the actin cytoskeleton which is required for successful engraftment. Overall design: Hematopoietic stem cells are regenerated in WT or Wnt5a-haploinsufficient niches. We profile LSK hematopoiteic stem cells after transplantation and three cell populations from the niche environment: endothelial cells (EC), osteoblastic cells (OBC), and mesenchymal cells (MSC)
Niche WNT5A regulates the actin cytoskeleton during regeneration of hematopoietic stem cells.
Cell line, Subject
View SamplesTumor relapse is associated with dismal prognosis, but responsible biological principles remain incompletely understood. To isolate and characterize relapse-inducing cells, we used genetic engineering and proliferation-sensitive dyes in patient-derived xenografts of acute lymphoblastic leukemia (ALL). We identified a rare subpopulation that resembled relapse-inducing cells with combined properties of long-term dormancy, treatment resistance, and stemness. Single-cell and bulk expression profiling revealed their similarity to primary ALL cells isolated from pediatric and adult patients at minimal residual disease (MRD). Therapeutically adverse characteristics were reversible, as resistant, dormant cells became sensitive to treatment and started proliferating when dissociated from the in vivo environment. Our data suggest that ALL patients might profit from therapeutic strategies that release MRD cells from the niche. Overall design: Gene expression profiles from two PDX ALL Samples (ALL-199 & ALL-265) were generated for either dormant (LRC) vs. dividing (non-LRC) cells or drug treated vs. non-treated cells. For single cell analysis one mouse were analyzed for each condition.
Characterization of Rare, Dormant, and Therapy-Resistant Cells in Acute Lymphoblastic Leukemia.
Specimen part, Treatment, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below. Purpose: Kaposi’s sarcoma (KS)-associated herpesvirus (KSHV) causes several lymphoproliferative disorders, including KS, a common AIDS-associated malignancy. Cellular and viral microRNAs (miRNAs) have been shown to play important roles in regulating the expression of genes in oncogenesis. Herpesviruses, including KSHV, encode for miRNAs that are involved in angiogenesis, inflammation and apoptosis. A better knowledge of the miRNA-mediated pathways that regulate KSHV infection is therefore essential for an improved understanding of viral infection and pathogenesis. Methods: In this study, we used deep sequencing to analyze miRNA, both viral and human, and mRNA expression in KS tumor-derived human cells. Results: This approach revealed 153 differentially expressed human miRNAs between KSHV-positive and -negative cells. Differential expression of eight miRNAs was independently confirmed by qRT-PCR. We additionally showed that a majority (~73%) of KSHV-regulated miRNAs are down-regulated, including most members of the 14q32 miRNA cluster. Specifically, human miR-409-3p, which is known to target the pro-angiogenic growth factor angiogenin and the inflammation marker fibrinogen-beta, was significantly down-regulated in KSHV-infected cells based on deep sequencing and qRT-PCR. Despite this substantial down-regulation of cellular miRNAs, hsa-miR-708-5p was significantly up-regulated by KSHV and has been shown to directly inhibit pro-apoptotic protease Caspase-2. Finally, we evaluated to what extent there was an inverse correlation between miRNA and mRNA expression levels. Using filtered datasets, we identified relevant canonical pathways that were significantly enriched. Conclusion: Taken together, our data demonstrate that most human miRNAs affected by KSHV are repressed and our findings highlight the relevance of studying the post-transcriptional gene regulation of miRNAs for KSHV-associated malignancies. Overall design: Refer to individual Series. 6 samples analyzed (one cell type). Two experimental conditions: uninfected vs. chronically KSHV-infected cells (n=3). Two sequencing platforms: microRNA-Seq and mRNA-Seq.
Next-Generation Sequencing Analysis Reveals Differential Expression Profiles of MiRNA-mRNA Target Pairs in KSHV-Infected Cells.
No sample metadata fields
View SamplesInterference with chemoresistance to enhance the efficacy of chemotherapeutics may be of great utility for cancer therapy. We have identified KINK-1 (Kinase Inhibitor of NF-kappaB-1), a highly selective small-molecule IKKkappa inhibitor, as a potent suppressor of both constitutive and induced NF-kappaB activity in melanoma cells. While KINK-1 profoundly diminished various NF-kappaB-dependent gene products regulating proliferation, cytokine production or anti-apoptotic responses, the compound by itself showed little antiproliferative or pro-apoptotic activity on the cellular level. However, its combination with some cytostatics markedly enhanced their antitumoral activities in vitro, and doxorubicin-induced NF-kappaB activation, a mechanism implicated in chemoresistance, was abrogated by KINK-1. In addition, when KINK-1 was combined with doxorubicin in an in vivo melanoma model, experimental metastasis was significantly diminished as compared to either treatment alone. Induction of chemoresistance by KINK-1 in vivo was not observed. Thus, KINK-1 or related substances might increase the susceptibility of tumors to chemotherapy.
KINK-1, a novel small-molecule inhibitor of IKKbeta, and the susceptibility of melanoma cells to antitumoral treatment.
No sample metadata fields
View SamplesThe relative contribution of polarized macrophages to the maintenance of tolerance is unknown. We examined their roles by in vivo adoptive transfer immunotherapy of M0, M1 and M2a macrophages as pre-treatment of colitis. In other experiments, M2a macrophages were used as pre-treatment or treatment of established colitis followed by immunotherapy with nTreg cells. Survival, weight gain, tissue infiltration, iTreg and Th17 cell development, T cell activation, and the frequency of proinflammatory cytokines were used as outcome measurements. Pre-treatment with M2a but not M1 macrophages increased the development of iTreg and Th17 cells. M2a macrophages used as pre-treatment or in treatment of established colitis allowed for successful therapy with nTreg cells.
Alternatively Activated Macrophages Boost Induced Regulatory T and Th17 Cell Responses during Immunotherapy for Colitis.
Age, Specimen part
View SamplesWe developed a novel approach combining next generation sequencing, bioinformatics and mass spectrometry to assess the impact of non-MHC polymorphisms on the repertoire of MHC I-associated peptides (MIPs). We compared the genomic landscape of MIPs eluted from B lymphoblasts of two MHC-identical siblings and determined that MIPs mirror the genomic frequency of non-synonymous polymorphisms but they behave as recessive traits at the surface level. Moreover, we showed that 11.7% of the MIP coding exome is polymorphic at the population level. Our method provides fundamental insights into the relation between the genomic self and the immune self and accelerates the discovery of polymorphic MIPs (also known as minor histocompatibility antigens), which play a major role in allo-immune responses. Overall design: RNA-seq of human B lymphoblasts derived from peripheral blood mononuclear cells from 2 HLA-identical female siblings.
Impact of genomic polymorphisms on the repertoire of human MHC class I-associated peptides.
Specimen part, Subject
View Samples