The identification of small molecules which either increase the number and/or enhance the activity of CD34+ hematopoietic stem and progenitor cells (HSPCs) during ex-vivo expansion has remained challenging. Applying an unbiased in vivo chemical screen in a transgenic (c-myb:EGFP) zebrafish embryo model, histone deacetylase inhibitors (HDACI) (valproic acid, resminostat and entinostat) were shown to significantly amplify the number of phenotypic hematopoietic precursors. The identified HDACIs were confirmed to significantly enhance also the expansion of human HSPCs during ex vivo treatment. Long-term functionality of ex vivo expanded human HSPCs was verified in a xenotransplantation model using NSG mice. However, the HDACI induced proliferation of HSPCs was associated with short-term functional changes. One of the identified hits, valproic acid (VPA), increased the adhesion capacity of CD34+ cells on primary mesenchymal stromal cells and reduced their chemokine-mediated migration capacity in vitro. In line with the reduced migratory potential in vitro, homing as well as early engraftment of VPA treated human CD34+ cells was significantly impaired in the xenotransplantation model. Our data confirms that HDACI treatment leads to a net expansion of HSPCs cells with long-term engraftment potential across different species. However impaired homing and short-term-engraftment has to be kept in mind when designing clinical transplantation protocols. In addition, our gene expression analysis (RNA-Seq) revealed expression of several genes that were altered in CD34+ cells by VPA treatment including cell adhesion molecules and Notch and wnt genes which has been shown to be involved in preservation of stem cell properties. Overall design: Gene expression analysis of in vitro expanded human HSPCs (CD34+ cells) by valproic acid
Zebrafish In-Vivo Screening for Compounds Amplifying Hematopoietic Stem and Progenitor Cells: - Preclinical Validation in Human CD34+ Stem and Progenitor Cells.
Disease, Subject
View SamplesThe original objectives of the study were to identify surface markers specifically expressed in motor neurons. We now use the data to profile the expression of Cdk family members in motor neurons.
Dual Inhibition of GSK3β and CDK5 Protects the Cytoskeleton of Neurons from Neuroinflammatory-Mediated Degeneration In Vitro and In Vivo.
Specimen part
View SamplesMacrophages are amongst the major targets of glucocorticoids (GC) as therapeutic anti-inflammatory agents. Here we show that GC treatment of mouse and human macrophages initiates a cascade of induced gene expression including many anti-inflammatory genes. Inducible binding of the glucocorticoid receptor (GR) was detected at candidate enhancers in the vicinity of induced genes in both species and this was strongly associated with canonical GR binding motifs. However, the sets of inducible genes, the candidate enhancers, and the GR motifs within them, were highly-divergent between the two species.
Enhancer Turnover Is Associated with a Divergent Transcriptional Response to Glucocorticoid in Mouse and Human Macrophages.
Sex, Age, Specimen part, Treatment, Time
View SamplesMacrophages are amongst the major targets of glucocorticoids (GC) as therapeutic anti-inflammatory agents. Here we show that GC treatment of mouse and human macrophages initiates a cascade of induced gene expression including many anti-inflammatory genes. Inducible binding of the glucocorticoid receptor (GR) was detected at candidate enhancers in the vicinity of induced genes in both species and this was strongly associated with canonical GR binding motifs. However, the sets of inducible genes, the candidate enhancers, and the GR motifs within them, were highly-divergent between the two species.. The data cast further doubt upon the predictive value of mouse models of inflammatory disease.
Enhancer Turnover Is Associated with a Divergent Transcriptional Response to Glucocorticoid in Mouse and Human Macrophages.
Specimen part, Treatment, Time
View SamplesWe have analyzed the transcript expression in different LCM-dissected cell layers isolated from mouse retinas adapted to light or dark in order to identify transcripts potentially targetted by retinal microRNAs which are regulated in response to light treatment
Characterizing light-regulated retinal microRNAs reveals rapid turnover as a common property of neuronal microRNAs.
Specimen part, Treatment
View SamplesThe cytosolic protein Sharpin is as a component of the linear ubiquitin chain assembly complex (LUBAC), which regulates NF-B signaling in response to specific ligands. Its inactivating mutation in Cpdm (chronic proliferative dermatitis mutation) mice causes multi-organ inflammation, yet this phenotype is not transferable into wildtype mice by hematopoietic stem cell transfer. Recent evidence demonstrated that Cpdm mice additionally display low bone mass, but the cellular and molecular causes of this phenotype remained to be established. Here we have applied non-decalcified histology together with cellular and dynamic histomorphometry to perform a thorough skeletal phenotyping of Cpdm mice. We show that Cpdm mice display trabecular and cortical osteopenia, solely explained by impaired bone formation, whereas osteoclastogenesis is unaffected. We additionally found that Cpdm mice display a severe disturbance of articular cartilage integrity in the absence of joint inflammation, supporting the concept that Sharpin-deficiency affects mesenchymal cell differentiation. Consistently, Cpdm mesenchymal cells displayed reduced osteogenic capacitiy ex vivo, yet this defect was not associated with impaired NF-B signaling. A molecular comparison of wildtype and Cpdm bone marrow cell populations further revealed that Cpdm mesenchymal cells produce higher levels of Cxcl5 and lower levels of IL1ra. Collectively, our data demonstrate that skeletal defects of Cpdm mice are not caused by chronic inflammation, but that Sharpin is as a critical regulator of mesenchymal cell differentiation and gene expression. They additionally provide an alternative molecular explanation for the inflammatory phenotype of Cpdm mice and the absence of disease transfer by hematopoetic stem cell transplantation.
Sharpin Controls Osteogenic Differentiation of Mesenchymal Bone Marrow Cells.
Specimen part
View SamplesWe disprove that the impaired Myd88-dependent proinflammatory response of neonatal monocytes is a correlate for immaturity and confirm it as display of transient alarmin-mediated stress tolerization. We find a strong inducibility of TRIF-dependent genes in neonatal monocytes by LPS but a barely detectable expression at baseline.
S100-alarmin-induced innate immune programming protects newborn infants from sepsis.
Specimen part, Treatment
View SamplesTo study the effect of balanced chromosomal rearrangements on gene expression, we compared the transcriptomes of cell lines from control and t(11;22)(q23;q11) individuals. This translocation between chromosomes 11 and 22 is the only recurrent constitutional non-Robertsonian translocation in humans. The number of differentially expressed transcripts between the translocated and control cohort is significantly higher than that observed between control samples alone, suggesting that balanced rearrangements have a greater effect on gene expression than normal variation. Altered expression is not limited to genes close to the translocation breakpoint suggesting that a long-range effect is operating. Indeed we show that the nuclear position of the derivative chromosome is altered compared to the normal chromosomes. Our results are consistent with recent studies that indicate a functional role for nuclear position in regulating the expression of some genes in mammalian cells. They may also have implications on reproductive separation, as we show that reciprocal translocations not only provide partial isolation for speciation but also significant changes in transcriptional regulation through alteration of nuclear chromosomes territories.
The effect of translocation-induced nuclear reorganization on gene expression.
Sex, Age, Specimen part
View SamplesModern functional genomic approaches may help to better understand the molecular events involved in tissue morphogenesis and to identify molecular signatures and pathways. We have recently applied transcriptomic profiling to evidence molecular signatures in the development of the normal chicken chorioallantoic membrane and in tumor engrafted on the CAM. We have now extended our studies by performing a transcriptome analysis in the wound model of the chicken CAM which is another relevant model of tissue morphogenesis. To induce granulation tissue formation, we performed wounding of the chicken CAM and compared gene expression to normal CAM at the same stage of development. Matched control samples from the same individual were used. We observed a total of 282 genes up-regulated and 44 genes downregulated assuming a false-discovery rate at 5 % and a fold change > 2. Furthermore, bioinformatics analysis lead to the identification of several categories that are associated to organismal injury, tissue morphology, cellular movement, inflammatory disease, development and immune system. Endothelial cell data filtering leads to the identification of several new genes with an endothelial cell signature. In summary, the chick chorioallantoic wound model allows the identification of gene signatures involved in granulation tissue formation and neoangiogenesis. This may constitute a fertile ground for further studies.
Gene signatures in wound tissue as evidenced by molecular profiling in the chick embryo model.
Specimen part
View SamplesNascent RNA was metabolically labelled with 4SU in undifferentiated and ESC-derived neural progenitor cells (NPCs). 4SU incorporated RNA was isolated and deep-sequenced at day 0 (ESCs), 3, 5 and 7 of differentiation. NPC differentiation was monitored through expression of a GFP reporter insereted into the Sox1 locus (46C reporter ESC line; PMID: 12524553). The aim was to monitor changes in transcription as ESCs differentiate into NPCs and relate this to enhancer activity. Overall design: For each of the 4 differentiation time points, two independent biological replicates were prepared and sequenced. For each assayed time point, both merged and individual replicate 4SU-seq profiles were generated.
Decreased Enhancer-Promoter Proximity Accompanying Enhancer Activation.
Specimen part, Cell line, Subject
View Samples