It is currently accepted that the human brain has a limited neurogenic capacity and an impaired regenerative potential. We have previously shown the existence of CD271-expressing neural stem cells (NSCs) in the subventricular zone (SVZ) of Parkinson's disease (PD) patients, which proliferate and differentiate towards neurons and glial cells in vitro. To study the molecular profile of these NSCs in detail, we performed RNA sequencing and mass spectrometry on CD271+ NSCs isolated from human post-mortem SVZ and on homogenates of the SVZ. CD271+ cells were isolated through magnetic cell separation (MACS). We first compared the molecular profile of CD271+ NSCs to the SVZ homogenate from control donors to assess the CD271+ NSCs gene signature and finally made a comparison between controls and PD patients to establish a specific molecular profile of NSCs and the SVZ in PD. While our transcriptome analysis did not identify any differentially expressed genes in the SVZ between control and PD patients, our proteome analysis revealed several proteins that were differentially expressed in PD. Some of these proteins are involved in cytoskeletal organization and mitochondrial function. Transcriptome and proteome analyses of NSCs from PD revealed changes in the expression of genes and proteins involved in metabolism, transcriptional activity and cytoskeletal organization. Our results not only confirm pathological hallmarks of PD (e.g. impaired mitochondrial function), but also suggest that NSCs may transit into a primed-quiescent state, that is in an “alert” non-proliferative phase in PD. Overall design: From post-mortem human SVZ of control and Parkinson disease donors we isolated CD271+ NSCs and Cd11b+ microglia by MACS and the whole SVZ to generate RNA sequencing libraries using Celseq2 method. We aimed for low coverage sequencing (~2 million mapped to the coding regions) per sample to investigate the gross changes in the transcriptome. Libraries (rpi small primer) were sequenced in 3 runs, 2 on an Illumina NextSeq500 using 75-bp paired-end sequencing at the Utrecht Seuqencing center (USEQ) and the third on a HiSeq4000 using 150-bp paired-end sequencing at Genomescan. All the samples were mapped in a single run to an average depth of ~10 million reads per sample. Reads were mapped to the latest human coding transcriptome using bwa, normalized and analyzed using the standard DESEQ2 package.
Transcriptome and proteome profiling of neural stem cells from the human subventricular zone in Parkinson's disease.
Specimen part, Subject
View SamplesPurpose: Identify zebrafish microglia transcriptome in the healthy and neurodegenerative brain. Methods: RNA sequencing was performed on FACS-sorted microglia (3x), other brain cells (3x) and activated microglia (4x). Microglia activation was induced using nitroreductase-mediated cell ablation. 10-20 million reads per sample were obtained. Reads were mapped to zebrafish genome GRC10. Results: We identified the zebrafish microglia transcriptome, which shows overlap with previously identified mouse microglia transcriptomes. Transcriptomes obtained 24h and 48h after treatment appeared highly similar. Therefore, these datasets were pooled. Additionally, we identified an acute proliferative response of microglia to induced neuronal cell death. Overall design: Zebrafish microglia transcriptomes of homeostatic microglia (triplicate), other brain cells (triplicate), activated microglia 24h (duplo), activated microglia 48h (duplo). In data analysis all activated microglia samples were pooled.
Identification of a conserved and acute neurodegeneration-specific microglial transcriptome in the zebrafish.
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Triplication of a 21q22 region contributes to B cell transformation through HMGN1 overexpression and loss of histone H3 Lys27 trimethylation.
Specimen part
View SamplesChildren with Down syndrome (DS) have a 20-fold increased risk of developing B cell acute lymphoblastic leukemia (B-ALL). Polysomy 21 (i.e., extra copies of chr.21) is also the most frequent somatic aneuploidy among all B-ALLs. Additional B-ALLs harbor intrachromosomal amplifications of chr.21q22 (iAMP21). Yet, the mechanistic links between chr.21q22 triplication and B-ALL remain undefined. Here we show that germline triplication of only 31 genes orthologous to human chr.21q22 is sufficient to confer murine B cell self-renewal in vitro, B cell maturation defects in vivo, and B-ALL in concert with either BCR-ABL or CRLF2 with activated JAK2. Chr.21q22 triplication suppresses H3K27me3 in murine progenitor B cells and B-ALLs, and bivalent genes with both H3K27me3 and H3K4me3 at their promoters in wild-type progenitor B cells are preferentially overexpressed in triplicated cells. Strikingly, human B-ALLs with polysomy 21 are distinguished by their overexpression of genes known to be marked with H3K27me3 in multiple cell types. Finally, overexpression of HMGN1, a nucleosome remodeling protein encoded on chr.21q22, suppresses H3K27me3 and promotes both B cell proliferation in vitro and B-ALL in vivo. These data implicate HMGN1 overexpression and loss of H3K27me3 in progenitor B cell transformation and suggest strategies to target leukemias with polysomy 21.
Triplication of a 21q22 region contributes to B cell transformation through HMGN1 overexpression and loss of histone H3 Lys27 trimethylation.
No sample metadata fields
View SamplesDrought is an important environmental factor affecting plant growth and biomass production. Despite this importance, little is known on the molecular mechanisms regulating plant growth under water limiting conditions. The main goal of this work was to investigate, using a combination of growth and molecular profiling techniques, how Arabidopsis thaliana leaves adapt their growth to prolonged mild osmotic stress. Fully proliferating, expanding and mature leaves were harvested from plants grown on plates without (control) or with 25mM mannitol (osmotic stress) and compared to seedlings at stage 1.03.
Developmental stage specificity and the role of mitochondrial metabolism in the response of Arabidopsis leaves to prolonged mild osmotic stress.
Specimen part
View SamplesWilms tumor (nephroblastoma) is a pediatric kidney tumor that arises from renal progenitor cells. Since the blastemal type is associated with adverse prognosis, we characterized such Wilms tumors by exome and transcriptome analysis. We detected novel, recurrent somatic mutations affecting the SIX1/2 SALL1 pathway implicated in kidney development, the DROSHA/DGCR8 microprocessor genes as well as alterations in MYCN and TP53, the latter being strongly associated with dismal outcome. The DROSHA mutations impair the RNase III domains, while DGCR8 exhibits stereotypic E518K mutations in the RNA binding domain - both may skew miRNA representation. SIX1 and SIX2 mutations affect a single hotspot (Q177R) in the homeodomain indicative of a dominant effect. In larger cohorts, these mutations cluster in blastemal and chemotherapy-induced regressive tumors that likely derive from blastemal cells and these are characterized by generally higher SIX1/2 expression. These findings broaden the spectrum of human cancer genes and may open new avenues for stratification and therapeutic leads for Wilms tumors.
Mutations in the SIX1/2 pathway and the DROSHA/DGCR8 miRNA microprocessor complex underlie high-risk blastemal type Wilms tumors.
Sex
View SamplesAging is a key factor in Alzheimer''s disease, but it''s correlation with the pathology and pathological factors like amyloid-beta remains unclear In our study we aimed to provide an extensive characterisation of age-related changes in the gene expression profile of APP23 mice and controls and correlate these changes to pathological and symptomatic features of the model We found a clear biphasic expression profile with a developmental and aging phase. The second phase, particularly, displays aging features and similarties with the progression of Alzheimer pathology in human patients Processes involved in microglial activation, lysosomal processing, neuronal differantion and cytoskeletal regulation appear key factors in this stage. Interestingly, the changes in the gene expression profile of APP23 mice also seem to occur in control animals, but at a later age. The changes appear accelerated and/or exacerbated in APP23 mice. Overall design: mRNA profiles of APP23 mice and wild-type control littermates aged 1.5, 6, 18 or 24 months. For all the age groups, samples of 3 mice of each genotype were analyzed
Aging, microglia and cytoskeletal regulation are key factors in the pathological evolution of the APP23 mouse model for Alzheimer's disease.
Age, Specimen part, Subject
View SamplesC/EBPalpha is a transcription factor critically involved in myeloid development and indispensable for formation of granulocytes. To track the cellular fate of stem and progenitor (LSK) cells, which express C/EBPalpha, we developed a mouse model expressing Cre recombinase from the Cebpa promoter and an inducible EYFP allele. We show that Cebpa/EYFP+ cells represent a significant subset of LSK cells, which predominantly give rise to myeloid cells in steady state hematopoiesis.
Lineage-instructive function of C/EBPα in multipotent hematopoietic cells and early thymic progenitors.
Specimen part
View SamplesThe final size of plant organs such as leaves is tightly controlled by environmental and genetic factors that must spatially and temporally coordinate cell expansion and cell cycle activity. However this regulation of organ growth is still poorly understood. The aim of this study is to gain more insight in the genetic control of leaf size in Arabidopsis by performing a comparative analysis of transgenic lines that produce larger leaves under standardized environmental conditions. To this end, we selected five genes, belonging to different functional classes, that all positively affect leaf size when over-expressed: AVP1, GRF5, JAW, BRI1 and GA20OX1. We show that the increase in leaf area in these lines depends on leaf position and growth conditions and that all five lines affect leaf size differently. However, in all cases an increase in cell number is, entirely or predominantly, responsible for the leaf size enlargement. By means of analyses of hormone levels, transcriptome and metabolome we provide deeper insight in the molecular basis of the growth phenotype for the individual lines. A comparative analysis between them indicates that enhanced organ growth is governed by different, seemingly independent pathways. The analysis of transgenic lines simultaneously over-expressing two growth-enhancing genes further supports the concept that multiple pathways independently converge on organ size control in Arabidopsis.
Increased leaf size: different means to an end.
Specimen part
View SamplesThe final size of plant organs such as leaves is tightly controlled by environmental and genetic factors that must spatially and temporally coordinate cell expansion and cell cycle activity. However this regulation of organ growth is still poorly understood. The aim of this study is to gain more insight in the genetic control of leaf size in Arabidopsis by performing a comparative analysis of transgenic lines that produce larger leaves under standardized environmental conditions. To this end, we selected five genes, belonging to different functional classes, that all positively affect leaf size when over-expressed: AVP1, GRF5, JAW, BRI1 and GA20OX1. We show that the increase in leaf area in these lines depends on leaf position and growth conditions and that all five lines affect leaf size differently. However, in all cases an increase in cell number is, entirely or predominantly, responsible for the leaf size enlargement. By means of analyses of hormone levels, transcriptome and metabolome we provide deeper insight in the molecular basis of the growth phenotype for the individual lines. A comparative analysis between them indicates that enhanced organ growth is governed by different, seemingly independent pathways. The analysis of transgenic lines simultaneously over-expressing two growth-enhancing genes further supports the concept that multiple pathways independently converge on organ size control in Arabidopsis.
Increased leaf size: different means to an end.
Specimen part
View Samples