The zebrafish is a powerful model for the study of hematopoietic stem and progenitor cells (HSPC). We have developed a novel HSPC-specific transgenic line (Runx1+23:GFP). We have used this line in time-lapse live imaging studies to track the migration of HSPC during development. We have also performed a chemical genetic screen to find small molecules that modulate HSPC numbers during development. Treating embryos from 2-3 days post fertilization (2-3 dpf) then fixing for in situ staining with HSPC probes cmyb and runx1, we found the compound lycorine increased HSPC numbers. Applying this compound during time-lapse live imaging showed increased accumulation of Runx+ HSPC in the caudal hematopoietic tissue (CHT). Treatment from 2-3 dpf, then washing off the compound, had a sustained effect on the size of the HSPC with Runx+ numbers higher at 5 and 7 dpf.
Hematopoietic stem cell arrival triggers dynamic remodeling of the perivascular niche.
Specimen part, Treatment
View SamplesThe transcription factor RUNX1 is frequently mutated in myelodysplastic syndrome and leukemia. RUNX1 mutations can be early events, creating pre-leukemic stem cells that expand in the bone marrow. Here we show that, counter-intuitively, Runx1 deficient hematopoietic stem and progenitor cells (HSPCs) have a slow growth, low biosynthetic, small cell phenotype and markedly reduced ribosome biogenesis (Ribi). The reduced Ribi involves decreased levels of rRNA and many mRNAs encoding ribosome proteins. Runx1 appears to directly regulate Ribi; Runx1 is enriched on the promoters of genes encoding ribosome proteins, and binds the ribosomal DNA repeats. Runx1 deficient HSPCs have lower p53 levels, reduced apoptosis, an attenuated unfolded protein response, and accordingly are resistant to genotoxic and endoplasmic reticulum stress. The low biosynthetic activity and corresponding stress resistance provides a selective advantage to Runx1 deficient HSPCs, allowing them to expand in the bone marrow and outcompete normal HSPCs. Overall design: Comparison of the phenotypic and molecular properties of normal (Runx1f/f, or WT) versus Runx1 deficient (Mut) hematopoietic stem cells.
Runx1 Deficiency Decreases Ribosome Biogenesis and Confers Stress Resistance to Hematopoietic Stem and Progenitor Cells.
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View SamplesResults showed that Chd7 deficiency delay Cbfb-MYH11 induced leukemia, to explore the mechanism, We also performed microarray analysis on c-Kit+ leukemic cells to determine gene expression differences between Mx1-Cre, Cbfb+/56M and Chd7f/f, Mx1-Cre, Cbfb+/56M leukemic cells.
<i>Chd7</i> deficiency delays leukemogenesis in mice induced by <i>Cbfb-MYH11</i>.
Specimen part
View SamplesRunx/Cbfb heterodimers play important roles in the development of hematopoietic cells in mouse embryos and adults. In order to identify genes that are regulated by Runx/Cbfb, we purified Lin c-kit+ Sca1+ (LSK) cells and Lin c-kit+ Sca1 CD16/32+ (GMP) cells from Vav1-iCre x Cbfb(F/F) and Vav1-iCre x Cbfb(F/+) mice and profiled gene expression using microarray.
Runx1 and Cbfβ regulate the development of Flt3+ dendritic cell progenitors and restrict myeloproliferative disorder.
Specimen part
View SamplesThe aim of this study is to evaluate the effect of Autoimmune regulator (Aire) gene disruption in a murine medullary thymic epithelial cells (mTEC 3.10 cell line) on the transcriptome of these cells during its adhesion with thymocytes. The mTEC-thymocyte adhesion is a crucial step for the negative selection of autoreactive thymocytes and prevention of autoimmune diseases. To generate Aire mutant cell clones, a total of 5x10^5 mTEC 3.10 cells were electro-transfected (Lonza Nucleofector) with CRISPR-Cas9 plasmid targeting the Aire Exon 3 (plasmid "all in one" encoding Aire Exon 3 gRNA + Cas9 + GFP, from Sigma-Aldrich). The GFP positive mTEC single cells were sorted by using a FACS Aria III cytometer and cells were cloned by expansion in culture. Sanger sequencing of PCR products from the Aire Exon 3 of these clones was used in order to evaluate the occurrence of indel mutations within the targeted Exon 3. The mTEC 3.10 clone E6 was identified and validated as a compound heterozygous Aire KO (Aire +/-). This clone features the Aire allele 1 that encodes a mutant Aire protein carring a neutral aminoacid substitution (A118P) and allele 2 encoding a truncated Aire protein. Wild type (WT) mTEC 3.10 cells or mTEC 3.10 clone E6 were cultured in the presence (or not) of thymocytes in order to establish cell adhesion. The total RNA preparations from WT or clone E6 mTEC cells (before or after mTEC- thymocyte co-cultures) were then sequenced through RNA-sequencing using a Illumina HiSeq 2500 instrument and the TruSeq Stranded mRNA Library Preparation kit resulting in about 50 million paired-end stranded specific 100 bp reads per sample. Sequencing reads were mapped to Mus musculus reference genome (mm10) using STAR v.2.5.0a. Read counts over transcripts were calculated using HTSeq v.0.6.1p2 based on a current UCSC annotation file for GRCm38/mm10 (Dec. 2011). Overall design: The mRNA profiles of mTEC 3.10 cells carring WT Aire (before or after co-culture with thymocytes) or heterozygous KO mTEC 3.10 cells (clone E6, Aire +/-) (before or after co-culture with thymocytes) were generated by sequencing, in duplicates, using a Illumina HiSeq 2500 instrument.
Aire Disruption Influences the Medullary Thymic Epithelial Cell Transcriptome and Interaction With Thymocytes.
Specimen part, Cell line, Subject
View SamplesLoss of Rb family in HSC results in their sustained proliferation, impaired homeostasis and extramedullar mobility.
Rb family proteins enforce the homeostasis of quiescent hematopoietic stem cells by repressing Socs3 expression.
Specimen part
View SamplesSmall RNA deep sequencing analysis was conducted on primary human fibroblasts infected with human cytomegalovirus (HCMV). HCMV-encoded miRNAs accumulated to ~20% of the total smRNA population at late stages of infection, and our analysis led to improvements in viral miRNA annotations and identification of novel HCMV miRNAs. Through crosslinking and immunoprecipitation of Argonaute-bound RNAs from infected cells, followed by high-throughput sequencing (Ago CLIP-seq), we obtained direct evidence for incorporation of all HCMV miRNAs into the endogenous host silencing machinery. Additionally, significant upregulation was observed during infection for a host miRNA cluster containing miR-96, miR-182 and miR-183. We also identified novel non-miRNA forms of virus-derived smRNAs, revealing greater complexity within the smRNA population during HCMV infection. Overall design: High-throughput profiling of smRNAs, Ago1-, and Ago2-associated miRNAs from HCMV-infected fibroblast cells. Wild-type HCMV Towne (Genbank FJ616285.1) was used for these studies.
High-resolution profiling and analysis of viral and host small RNAs during human cytomegalovirus infection.
Specimen part, Treatment, Subject
View SamplesEGR3 expression is upregulated in human prostate cancer compared to normal prostate tissue and is associated with absence of relapse, while low EGR3 expression in tumors is predicitive of disease relapse (Pio et al., PLOS One 2013; 8(1):e54096). However the function of EGR3 in prostate cancer is unknown. Human prostate cancer cells M12 containing high levels of EGR3 were used for shRNA-mediated silencing of EGR3. Gene expression analysis of EGR3 knockdown cells reveals a role in inflammation and the existence of a crosstalk with the NFkB pathway.
Early growth response 3 (Egr3) is highly over-expressed in non-relapsing prostate cancer but not in relapsing prostate cancer.
Cell line, Treatment
View SamplesWe modeled human Trisomy 21 primitive hematopoiesis using induced pluripotent stem cells (iPSCs). Primitive multipotent progenitor populations generated from Trisomy 21 iPSCs showed normal proliferative capacity and megakaryocyte production, enhanced erythropoiesis and reduced myeloid development compared to euploid iPSCs.
Trisomy 21-associated defects in human primitive hematopoiesis revealed through induced pluripotent stem cells.
Specimen part
View SamplesPrimary pediatric Ewing sarcoma (ES), one uncharacterized sarcoma as well as primary and well established ES cell lines were compared to probes of different normal tissues
Distinct transcriptional signature and immunoprofile of CIC-DUX4 fusion-positive round cell tumors compared to EWSR1-rearranged Ewing sarcomas: further evidence toward distinct pathologic entities.
Specimen part, Cell line, Subject
View Samples