The cellular response to DNA damage is vital for maintaining genomic stability and preventing undue cell death or cancer formation. The DNA damage response (DDR), most robustly mobilized by double-strand breaks (DSBs), rapidly activates an extensive signaling network that affects numerous cellular systems, leading to cell survival or programmed cell death. A major component of the DDR is the widespread modulation of gene expression. We analyzed transcriptional responses to ionizing radiation (IR) in 5 human cell lines to elucidate the scope of this response and identify its gene targets. According to the mRNA expression profiles most of the responses were cell line-specific. Data analysis identified significant enrichment for p53 target genes and cell cycle-related pathways among groups of up-regulated and down-regulated genes, respectively.
Transcriptional modulation induced by ionizing radiation: p53 remains a central player.
Cell line, Time
View SamplesThe DNA damage response network modulates a wide array of signaling pathways, including DNA repair, cell cycle checkpoints, apoptotic pathways and numerous stress signals. The ATM protein kinase, functionally missing in patients with the human genetic disorder ataxia-telangiectasia (A-T), is a master regulator of this network when the inducing DNA lesions are double strand breaks. The ATM gene is also frequently mutated in sporadic cancers of lymphoid origin. Here, we applied a functional genomics approach that combines gene expression profiling and computational promoter analysis to obtain global dissection of the transcriptional response to ionizing radiation (IR) in murine lymphoid tissue. Cluster analysis revealed six major expression patterns in the data. Prominent among them was a gene cluster that contained dozens of genes whose response to irradiation was Atm-dependent. Computational analysis identified significant enrichment of the binding site signatures of the transcription factors NF-kB and p53 among promoters of these genes, pointing to the major role of these two transcription factors in mediating the Atm-dependent transcriptional response in the irradiated lymphoid tissue. Examination of the response showed that pro- and anti-apoptotic signals were simultaneously induced, with the pro-apoptotic pathway mediated by p53, and the pro-survival pathway by NF-kB. These findings further elucidate the molecular network induced by IR and have implications for cancer management as they suggest that a combined treatment that restores the p53-mediated apoptotic arm while blocking the NF-kB-mediated pro-survival arm could be most successful in increasing the radiosensitivity of lymphoid tumors.
Parallel induction of ATM-dependent pro- and antiapoptotic signals in response to ionizing radiation in murine lymphoid tissue.
No sample metadata fields
View SamplesHere we show that biotin-labelled miR-34a can be loaded to AGO2, and AGO2 immunoprecipitation can pulldown biotinylated miR-34a (Bio-miR pulldown). RNA-sequencing (RNA-seq) of the Bio-miR pulldown RNAs efficiently identified miR-34a mRNA targets, which could be verified with luciferase assays. In contrast to the approach of Bio-miR pulldown, RNA-seq of miR-34a overexpression samples had limited value in identifying direct targets of miR-34a. It seems that pulldown of 30 -Biotin-tagged miRNA can identify bona fide microRNA targets at least for miR34a. Overall design: biotin-labelled miR-34a pulldown and RNA sequencing of miR-34a overexpression samples
Comparing two approaches of miR-34a target identification, biotinylated-miRNA pulldown vs miRNA overexpression.
Cell line, Subject
View SamplesAdult hematopoiesis has been studied in terms of progenitor differentiation potentials, whereas its kinetics in vivo is poorly understood. We combined inducible lineage tracing of endogenous adult hematopoietic stem cells (HSC) with flow cytometry and single-cell RNA sequencing to characterize early steps of hematopoietic differentiation in the steady state. Labeled cells, comprising primarily long-term HSC and some short-term HSC, produced megakaryocytic lineage progeny within one week, in a process that required only 2-3 cell divisions. Erythroid and myeloid progeny emerged simultaneously by 2 weeks, and included a progenitor population with expression features of both lineages. Myeloid progenitors at this stage showed diversification into granulocytic, monocytic and dendritic cell types, and rare intermediate cell states could be detected. In contrast, lymphoid differentiation was virtually absent within the first 3 weeks of tracing. These results show that continuous differentiation of HSC rapidly produces major hematopoietic lineages and cell types, and reveal fundamental kinetic differences between megakaryocytic, erythroid, myeloid and lymphoid differentiation. Overall design: We combined inducible lineage tracing of endogenous adult hematopoietic stem cells (HSC) with flow cytometry and single-cell RNA sequencing to characterize early steps of hematopoietic differentiation in the steady state.
Kinetics of adult hematopoietic stem cell differentiation in vivo.
Specimen part, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
CXCL10 is critical for the progression and maintenance of depigmentation in a mouse model of vitiligo.
Specimen part
View SamplesSkin samples from mice in a model of vitiligo were selected for gene expression profiling in order to identify active inflammatory pathways.
CXCL10 is critical for the progression and maintenance of depigmentation in a mouse model of vitiligo.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Critical Role of STAT5 transcription factor tetramerization for cytokine responses and normal immune function.
Specimen part, Treatment, Time
View SamplesCytokine-activated STAT proteins dimerize and bind to high-affinity motifs, and N-terminal domain-mediated oligomerization of dimers allows tetramer formation and binding to low-affinity tandem motifs, but the functions of dimers versus tetramers are unknown. We generated Stat5a and Stat5b double knock-in (DKI) N-domain mutant mice that form dimers but not tetramers, identified cytokine-regulated genes whose expression required STAT5 tetramers, and defined consensus motifs for dimers versus tetramers. Whereas Stat5- deficient mice exhibited perinatal lethality, DKI mice were viable, indicating that STAT5 dimers were sufficient for survival. Nevertheless, STAT5 DKI mice had fewer CD4+CD25+ T cells, NK cells, and CD8+ T cells, with impaired cytokine-induced proliferation and homeostatic proliferation of CD8+ T cells. DKI CD8+ T cell proliferation following viral infection was diminished and DKI Treg cells did not efficiently control colitis. Thus, tetramerization of STAT5 is dispensable for survival but is critical for cytokine responses and normal immune function.
Critical Role of STAT5 transcription factor tetramerization for cytokine responses and normal immune function.
Specimen part, Treatment, Time
View Samples10 day old seedlings were treated with 5uM of the cytokinin Benzyladenine(BA)or DMSO at 15min, 45min, 120min, 480min and 1440min
Expression profiling of cytokinin action in Arabidopsis.
Age, Compound, Time
View SamplesTranscriptome levels of matched patient-derived xenograft (PDX) in vitro-in vivo models. Overall design: Comparison of gene expression levels between matched patient-derived xenograft in vitro-in vivo models.
Generation of matched patient-derived xenograft in vitro-in vivo models using 3D macroporous hydrogels for the study of liver cancer.
Specimen part, Disease, Subject
View Samples