Differentiation 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 SamplesYin and yang 1 (YY1) is a well-known zinc-finger transcription factor with crucial roles in normal development and malignancy. YY1 acts both as a repressor and an activator of gene expression. We have identified 23 individuals with de novo mutations or deletions of YY1 and phenotypic features that define a syndrome of cognitive impairment, behavioral alterations, intrauterine growth retardation, feeding problems, and various congenital malformations. Our combined clinical and molecular data define the 'YY1 syndrome' as a haploinsufficiency syndrome. Through immunoprecipitation of YY1-bound chromatin from person-derived cells, using antibodies recognizing both ends of the protein, we show that YY1 deletions and missense mutations lead to a global loss of YY1 binding, with a preferential retention at high-occupancy sites. Finally, we uncover a widespread loss of H3K27 acetylation in particular on the YY1-bound enhancers, underscoring a crucial role for YY1 in enhancer regulation. Collectively, these results define a clinical syndrome caused by haploinsufficiency of YY1 through dysregulation of key transcriptional regulators. Overall design: Individuals with mutations or deletion in YY1 were identified among patients with idiopathic intellectual disability. LCLs were established from 4 of these patients (1 deletion, 2 missense mutations, and 1 non-sense mutation undergoing non-sense-mediated decay) as well as from unrelated controls, and their transcriptome were compared.
YY1 Haploinsufficiency Causes an Intellectual Disability Syndrome Featuring Transcriptional and Chromatin Dysfunction.
Specimen part, Subject
View SamplesAs part of the civil aviation safety program to define the adverse effects of ethanol on flying performance, we present results of our DNA microarray analysis of samples from a timecourse study of individuals given ethanol orally, and then evaluated by breathalyzer to monitor blood alcohol content (BAC). At five blood alcohol levels, T1-T5, blood was drawn such that the samples represented 0%, 0.04%, 0.08% BAC, and return to 0.04%, and 0.02% BAC. Microarray analysis showed that changes in gene expression could be detected across the time-course. We verified these expression changes by quantitative polymerase chain reaction (qPCR). Candidate target genes identified from the microarray analysis were clustered by expression change pattern, examined for shared functions and functional network membership. Five coordinately expressed groups were revealed and functional analysis showed shared transcription factor binding sites and functions for members of the clusters. These functions include protein synthesis and modification, expected for changes in gene expression, hematological and immune functions, expected for a blood sample, and pancreatic and hepatic function, expected as response to ethanol. The results provide a first look at changing gene expression patterns in blood during acute increase of ethanol concentration and its depletion due to metabolism or excretion and demonstrate that it is possible to detect significant changes in gene expression using total RNA isolated from whole blood. The analysis approach for this study can be utilized as part of a workflow to identify target genes by timecourse changes in gene expression that may affect pilot performance.
Microarray characterization of gene expression changes in blood during acute ethanol exposure.
Sex, Specimen part
View SamplesPositioned nucleosomes limit the access of proteins to DNA and implement regulatory features encoded in eukaryotic genomes. Here we generated the first genome-wide nucleosome positioning map for Schizosaccharomyces pombe and annotated transcription start and termination sites genome-wide. Using this resource we found surprising differences compared to the nucleosome organization in the distantly related yeast Saccharomyces cerevisiae [the cerevisiae data has been published by others (PMID: 17873876) and the raw data is deposited at ArrayExpress(E-MEXP-1172)]. DNA sequence guides nucleosome positioning differently, e.g., poly(dA:dT) elements are not enriched in S. pombe nucleosome-depleted regions (NDRs). Regular nucleosomal arrays emanate more asymmetrically, i.e., mainly co-directionally with transcription, from promoter NDRs, but promoters harbouring the histone variant H2A.Z show regular arrays also upstream. Regular nucleosome phasing in S. pombe has a very short repeat length of 154 base pairs, and requires a remodeler, Mit1, conserved in humans but not found in S. cerevisiae. Nucleosome positioning mechanisms are evidently not universal but evolutionarily plastic.
Schizosaccharomyces pombe genome-wide nucleosome mapping reveals positioning mechanisms distinct from those of Saccharomyces cerevisiae.
No sample metadata fields
View SamplesmRNA expression profiling of pancreatic cancer, comparing adjacent normal tissue, patient tumour and first generation patient derived xenograft tumours
Establishment and Characterisation by Expression Microarray of Patient-Derived Xenograft Panel of Human Pancreatic Adenocarcinoma Patients.
Specimen part
View SamplesTotal RNA was isolated from proliferating and senescent IMR90 cells to compare gene-expression to the changes in nucleolus-association in proliferating and senescent IMR90 cells.
Nucleolus association of chromosomal domains is largely maintained in cellular senescence despite massive nuclear reorganisation.
Specimen part
View SamplesWe studied differences in gene expression between Populus P35S::EBB1 lines and control, affecting plant growth and differentiation, and dormancy. We used microarrays to detail the global program of gene expression underlying morphological and developmental changes driven by overexpression of the EBB1 gene.
EARLY BUD-BREAK 1 (EBB1) is a regulator of release from seasonal dormancy in poplar trees.
Specimen part
View SamplesWe study gene expression Populus amiEBB1 lines affecting dormancy. We used microarrays to detail the global program of gene expression underlying morphological and developmental changes droved by expression of artifical micro RNA (ami) targeting EBB1 gene.
EARLY BUD-BREAK 1 (EBB1) is a regulator of release from seasonal dormancy in poplar trees.
Specimen part
View SamplesExpression data from HeLa cells treated with V-ATPase inhibitors or with desoxyferramine compared to HeLa treated with DMSO or medium with low LDL
Inhibition of iron uptake is responsible for differential sensitivity to V-ATPase inhibitors in several cancer cell lines.
Cell line
View SamplesPlants regulate their time to flowering by gathering information from the environment. Photoperiod and temperature are among the most important environmental variables. Suboptimal, but not near-freezing, temperatures regulate flowering through the thermosensory pathway, which overlaps with the autonomous pathway. Here we show that ambient temperature regulates flowering by two genetically distinguishable pathways, one that requires TFL1 and another that requires ELF3. The delay in flowering time observed at lower temperatures was partially suppressed in single elf3 and tfl1 mutants, whereas double elf3 tfl1 mutants were insensitive to temperature. tfl1 mutations abolished the temperature response in cryptochrome mutants that are deficient in photoperiod perception, but not in phyB mutants that have a constitutive photoperiodic response. Contrary to tfl1, elf3 mutations were able to suppress the temperature response in phyB mutants, but not in cryptochrome mutants. The gene expression profile revealed that the tfl1 and elf3 effects are due to the activation of different sets of genes and identified CCA1 and SOC1/AGL20 as being important cross talk points. Finally, genome-wide gene expression analysis strongly suggests a general and complementary role for ELF3 and TFL1 in temperature signalling.
A complementary role for ELF3 and TFL1 in the regulation of flowering time by ambient temperature.
No sample metadata fields
View Samples