Base Editing has been touted the most intelligent and precise application of the CRISPR platform so far, merging the simplicity of RNA-guided nucleases with deaminases that allow for the programmable generation of single base substitutions - without introduction of double-strand breaks. Even though the two-component system has been expected to cause off-target substitutions, studies involving cytosine base editors (CBEs) showed that in most cases, relatively few single base off-targets could be detected on DNA. We introduce the concept of multi-dimensional off-targeting, presenting an extensive amount of RNA cytidines being edited by DNA base editors. Epitranscriptomic off-target effects affected different cell lines and were independent of the guide RNAs used, suggesting Cas9-independent activity of the cytidine deaminase rAPOBEC1 on single-stranded RNA. With the help of protein engineering, we developed CBE variants with massively reduced inadvertent mutation of RNA that preserve and enhance DNA base editing capabilities. Overall design: HEK293T and HepG2 cells were transfected with regular and modified pCAG-BE3-P2A-EGFP or control pCAG-nCas9(D10A)-UGI-NLS-P2A-EGFP or control pCAG-P2A-EGFP constructs with various gRNAs as described below. Cells were sorted for top 5% GFP or all GFP + cells based on FITC signal. RNA-seq was performed to measure transcriptional changes associated with different constructs and guides.
Transcriptome-wide off-target RNA editing induced by CRISPR-guided DNA base editors.
Cell line, Treatment, Subject
View SamplesBase Editing has been touted the most intelligent and precise application of the CRISPR platform so far, merging the simplicity of RNA-guided nucleases with deaminases that allow for the programmable generation of single base substitutions - without introduction of double-strand breaks. Even though the two-component system has been expected to cause off-target substitutions, studies involving cytosine base editors (CBEs) showed that in most cases, relatively few single base off-targets could be detected on DNA. We introduce the concept of multi-dimensional off-targeting, presenting an extensive amount of RNA cytidines being edited by DNA base editors. Epitranscriptomic off-target effects affected different cell lines and were independent of the guide RNAs used, suggesting Cas9-independent activity of the cytidine deaminase rAPOBEC1 on single-stranded RNA. With the help of protein engineering, we developed CBE variants with massively reduced inadvertent mutation of RNA that preserve and enhance DNA base editing capabilities. Overall design: HEK293T and HepG2 cells were transfected with pCAG-BE3-P2A-EGFP or control pCAG-nCas9(D10A)-UGI-NLS-P2A-EGFP or control pCAG-P2A-EGFP constructs with various gRNAs as described below. Cells were sorted for top 5% GFP or all GFP + cells based on FITC signal. RNA-seq was performed to measure transcriptional changes associated with different constructs and guides.
Transcriptome-wide off-target RNA editing induced by CRISPR-guided DNA base editors.
Cell line, Treatment, Subject
View SamplesBase Editing has been touted the most intelligent and precise application of the CRISPR platform so far, merging the simplicity of RNA-guided nucleases with deaminases that allow for the programmable generation of single base substitutions - without introduction of double-strand breaks. Even though the two-component system has been expected to cause off-target substitutions, studies involving cytosine base editors (CBEs) showed that in most cases, relatively few single base off-targets could be detected on DNA. We introduce the concept of multi-dimensional off-targeting, presenting an extensive amount of RNA cytidines being edited by DNA base editors. Epitranscriptomic off-target effects affected different cell lines and were independent of the guide RNAs used, suggesting Cas9-independent activity of the cytidine deaminase rAPOBEC1 on single-stranded RNA. With the help of protein engineering, we developed CBE variants with massively reduced inadvertent mutation of RNA that preserve and enhance DNA base editing capabilities. Overall design: HEK293T cells were transfected with pCAG-BE3-P2A-EGFP or variants thereof or control pCAG-nCas9(D10A)-UGI-NLS-P2A-EGFP or control pCAG-P2A-EGFP constructs with various gRNAs as described below. Cells were sorted for top 5% GFP or all GFP + cells based on FITC signal. RNA-seq was performed to measure transcriptional changes associated with different constructs and guides.
Transcriptome-wide off-target RNA editing induced by CRISPR-guided DNA base editors.
Cell line, Treatment, Subject
View SamplesBipolar disorder (BD) has an estimated heritability of about 80%. Different pathways and candidate genes may contribute to the pathogenesis of BD, but definite mechanisms are yet unresolved. In a previous study, we identified the single nucleotide polymorphism (SNP) rs4500567, located in the upstream region of Tetraspanin 8 (TSPAN8), to be associated with bipolar disorder (BD).
The regulation of tetraspanin 8 gene expression-A potential new mechanism in the pathogenesis of bipolar disorder.
Cell line
View SamplesBase Editing has been touted the most intelligent and precise application of the CRISPR platform so far, merging the simplicity of RNA-guided nucleases with deaminases that allow for the programmable generation of single base substitutions - without introduction of double-strand breaks. Even though the two-component system has been expected to cause off-target substitutions, studies involving cytosine base editors (CBEs) showed that in most cases, relatively few single base off-targets could be detected on DNA. We introduce the concept of multi-dimensional off-targeting, presenting an extensive amount of RNA cytidines being edited by DNA base editors. Epitranscriptomic off-target effects affected different cell lines and were independent of the guide RNAs used, suggesting Cas9-independent activity of the cytidine deaminase rAPOBEC1 on single-stranded RNA. With the help of protein engineering, we developed CBE variants with massively reduced inadvertent mutation of RNA that preserve and enhance DNA base editing capabilities. Overall design: HEK293T or HepG2 cells were transfected with P2A-EGFP. Cells were sorted for top 5% GFP based on FITC signal. RNA-seq was performed to measure transcriptional changes associated with different constructs.
Transcriptome-wide off-target RNA editing induced by CRISPR-guided DNA base editors.
Specimen part, Treatment, Subject
View SamplesTo get insight in the functional role of EGR2 for Ewing sarcoma, we performed a transcriptional profiling of Ewing sarcoma cells after knockdown of EGR2 and compared the resulting transcriptional signature with that of EWSR1-FLI1-silenced Ewing sarcoma cells. In accordance with the strong EGR2-induction by EWSR1-FLI1, both genes highly significantly overlap in their transcriptional signatures. Gene-set enrichment analyses (GSEA) and DAVID (Database for Annotation, Visualisation and Integrated Discovery) gene ontology analyses indicated a strong impact of EGR2 on cholesterol and lipid biosynthesis resembling its function in orchestrating lipid metabolism of myelinating Schwann cells.
Chimeric EWSR1-FLI1 regulates the Ewing sarcoma susceptibility gene EGR2 via a GGAA microsatellite.
Cell line, Treatment
View SamplesIn order to identify genes that are activated in differentiating WT ESCs, but are missing in Tal-1-/- and Runx1-/- ESCs, and which might be involved in the generation of definitive hematopoietic progenitors and their specification thereafter, we performed microarray analyses on purified Flk-1+ cells, differentiated from these ESCs for 4, 5, and 6 days in vitro.
Ectopic Runx1 expression rescues Tal-1-deficiency in the generation of primitive and definitive hematopoiesis.
Specimen part, Cell line, Time
View SamplesRecent data from our group, demonstrate that infusion of myelin oligodendrocyte glycoprotein (MOG35-55) peptide, leads to induction of MOG35-55-specific Tregs and subsequent suppression of Experimental Autoimmune Encephalomyelitis (EAE), the mouse model of multiple sclerosis. Amelioration of EAE was accompanied by reduced MOG-specific Th1 and Th17 responses in the draining lymph nodes (dLNs). Phenotypic analysis of the dLNs of MOG-infused mice revealed a significant Treg-mediated reduction in the recruitment of 7AAD-CD3-CD19-CD11c+CD11bhighGr-1+ iDCs compared to non-infused control immunized mice. Focusing on the delineation of novel molecules/genes that are involved in the MOG-specific Treg-mediated suppression of autoimmune responses, we have isolated highly purified iDCs from MOG infused and non-infused control immunized mice.
De novo-induced self-antigen-specific Foxp3+ regulatory T cells impair the accumulation of inflammatory dendritic cells in draining lymph nodes.
Sex, Specimen part
View SamplesPreB cells were analyzed for differences in gene expression before and after the overexpression of miR-221. In order to dissect possible targets for the miR-221, gene expression profiles of preB cells un-induced or induced for the miR-221 expression after 8, 16 and 24 hours were compared. All induction time-points, e.g. after 8, 16 and 24 hours were compared to un-induced preB cells and to each other group.
SiPaGene: A new repository for instant online retrieval, sharing and meta-analyses of GeneChip expression data.
Specimen part
View SamplesMessenger (m)RNA export from the nucleus is essential for eukaryotic gene expression. Here, we identify a transcript-selective nuclear export mechanism affecting certain human transcripts, enriched for functions in genome duplication and repair, controlled by inositol polyphosphate multikinase (IPMK), an enzyme catalyzing inositol polyphosphate and phosphoinositide turnover. We studied transcripts encoding RAD51, a protein essential for DNA repair by homologous recombination (HR), to characterize the mechanism underlying IPMK-regulated mRNA export. IPMK depletion or catalytic inactivation selectively decreases the nuclear export of RAD51 mRNA, and RAD51 protein abundance, thereby impairing HR. Recognition of a sequence motif in the untranslated region of RAD51 transcripts by the mRNA export factor ALY requires IPMK. Phosphatidylinositol (3,4,5)-trisphosphate (PIP3), an IPMK product, restores ALY recognition in IPMK-depleted cell extracts, suggesting a mechanism underlying transcript selection. Our findings implicate IPMK in a transcript-selective mRNA export pathway controlled by phosphoinositide turnover that preserves genome integrity in humans.
Human inositol polyphosphate multikinase regulates transcript-selective nuclear mRNA export to preserve genome integrity.
Cell line
View Samples