Project description:The study of the compond PIP-RBPJ-1‘ function on neural stem cell. Synthetic DNA-binding inhibitors capable of gaining precise control over neurogenesis factors could obviate the current clinical barriers associated with small molecule use in regenerative medicine. Here, we show the design and bio-efficacy of a synthetic ligand PIP-RBPJ-1 to cause promoter-specific suppression of neurogenesis-associated HES1, and its downstream genes. Furthermore, PIP-RBPJ-1 alone could alter the neural system-associated notch signaling factors and remarkably induce neurogenesis with an efficiency that is comparable to a conventional approach. Here is one day treatment of the PIP-RBPJ-1 on neural stem cells.
Project description:Here we performed a ChIP-seq experiment on a sample of adherent cultures of mouse neural stem cells (NS5 cell line) under normal growth conditions. This resulted in the generation of a genome-wide map of RBPJ binding to chromatin.
Project description:Neural stem cells, located in discrete niches in the adult brain, generate new neurons throughout life. These stem cells are specialized astrocytes, but astrocytes in other brain regions (parenchymal astrocytes) do not generate neurons under physiological conditions. After stroke, however, astrocytes in the mouse striatum undergo neurogenesis, triggered by decreased Notch signaling. Notch signaling can be experimentally depleted in mice by deleting the Notch-mediating transcription factor Rbpj. This dataset consists of single-cell RNA sequencing data of astrocytes isolated from the striatum (where astrocytes undergo neurogenesis in response to Rbpj deletion) or somatosensory cortex (where astrocytes don't complete neurogenesis in response to Rbpj deletion) of 4 mice. Cells were isolated from Cx30-CreER; R26-tdTomato; Rbpj(fl/fl) mice at three time points after tamoxifen-induced Rbpj deletion (2, 4, 8 weeks), and from Cx30-CreER; R26-tdTomato mice with intact Rbpj 3 days after tamoxifen. These time points span the transition from astrocyte through transit-amplifying cells to neuroblasts. The dataset contains 1) astrocytes from the striatum that initiate a neurogenic transcriptional program in response to Rbpj deletion and generate transit-amplifying cells and neuroblasts, and 2) astrocytes from the somatosensory cortex that initiate a neurogenic program in response to Rbpj deletion but fail to generate transit-amplifying cells or neuroblasts.
Project description:From the cell-based investigation, RBPJ is one of the few proteins retained on chromatin during cell division. ChIP-seq experiments were performed to understand the binding pattern of RBPJ between interphase and mitosis and to identify the genes requiring RBPJ binding for the maintenance of transcriptional memory. Our results indicate that ~60% of RBPJ occupancy in interphase is retained on mitotic chromatin, and that accounts for 80% of RBPJ in mitosis. The gene ontology analysis reveals that the genes involved in stem cell maintenance, development and differentiation-related pathways correlated with sites of RBPJ occupancy. GO analysis also suggests that RBPJ plays a role in the metabolism and processing of non-coding RNAs. Motif analysis of RBPJ binding sites reveals that not only RBPJ motif but also CTCF motif are enriched around RBPJ binding sites. From these results, we propose that RBPJ can function as a mitotic bookmark, marking genes for efficient transcriptional activation or repression upon exit from mitosis, and may play a role in higher order chromatin structure by collaborating with CTCF. To compare the genomic RBPJ localization in mitotic and interphase cells, mouse F9 cells were harvested and labeled as cycling cells (containing 95% interphase and 5% mitosis cells); nocodazole treated F9 cells were harvested and labeled as mitotic cells. Cell samples were proceeded to ChIP-seq experiments, and each of the experiment contains a set of ChIP DNA product: input as the background control and IP as the RBPJ binding product. Background noise was substracted and the obtained signal was used for the comparison of interphase and mitosis by statistical analysis. Please note that processed data (*bed) was generated from *rep1 sample (i.e. no processed-data for rep2 sample).
Project description:The transcriptional regulator Rbpj is involved in T-helper (TH) subset polarization, but its function in Treg cells remains unclear. Here we show that Treg-specific Rbpj deletion leads to splenomegaly and lymphadenopathy despite increased numbers of Treg cells with a polyclonal TCR repertoire. A specific defect of Rbpj-deficient Treg cells in controlling TH2 polarization and B cell responses was observed, leading to the spontaneous formation of germinal centers and a TH2-associated immunoglobulin class switch as well as T-cell polarization into TH2 effector cells. The observed phenotype was environment-dependent and could be induced by infection with parasitic nematodes. Rbpj-deficient Treg cells adopted open chromatin landscapes and gene expression profiles reminiscent of tissue-derived TH2-polarized Treg cells, with a prevailing footprint of transcription factor Gata-3. The over-expression of Ilt3 rendered Rbpj-deficient Treg cells incompatible to specifically restrain TH2 responses, finally leading to severe and fatal lymphoproliferative disease.
Project description:We achieved local recombination of striatal astrocytes and silenced Notch signalling activity through Rbpj-K depletion. Recombined astrocytes and neural progenitors generated from the striaral glia were FAC sorted and their molecular profile investigated in a scRNAseq experiment performed 5 wpi.
Project description:To overview compound-responsive genes in fibroblast, we performed microarray analysis of ~63,000 genes in compound-treated fibroblast of LSND3
Project description:Dysregulation of the Notch-RBPJ signaling pathway has been found associated with various human diseases including cancers; however, precisely how this key signaling pathway is fine-tuned via its interactors and modifications is still largely unknown. In this study, using a proteomic approach, we identified FBXO42 as a novel RBPJ interactor. FBXO42 promotes RBPJ polyubiquitination on lysine (K) 175 via K63 linkage, which enhances the association of RBPJ with chromatin remodeling complexes and induces a global chromatin relaxation. Genetically depleting FBXO42 or pharmacologically targeting its E3 ligase activity attenuates the Notch signaling-related leukemia development in vivo. Taken together, our findings not only revealed FBXO42 as a critical regulator of the Notch pathway by modulating RBPJ-dependent global chromatin landscape changes, but also provide insights into the therapeutic intervention of the Notch pathway for leukemia treatment.
Project description:We discovered a new class of small molecule inhibitor that disrupts the interaction between NOTCH and RBPJ, which is the main transcriptional effector of NOTCH signaling. RBPJ Inhibitor-1 (RIN1) also blocked the functional interaction of RBPJ with SHARP, a scaffold protein that forms a transcriptional repressor complex with RBPJ in the absence of NOTCH signaling. RIN1 induced changes in gene expression resembled siRNA silencing of RBPJ rather than inhibition at the level of NOTCH itself. RIN1 inhibits RBPJ in its repressing and activating contexts.
Project description:Notch signaling is an evolutionarily conserved signal transduction pathway that is essential for metazoan development. At the molecular level, the key components of the Notch pathway are the NOTCH-family receptors, the ligands of the DSL (Delta, Serrate, Lag-2) family and the transcription factor CSL [CBF1/RBPJ, Su(H), Lag-1]. Upon ligand binding, the NOTCH Intra-Cellular Domain (NOTCH ICD) translocates into the nucleus and forms a complex with RBPJ to activate the transcription of target genes. In the absence of NOTCH ICD, RBPJ acts as a transcriptional repressor. Using a proteomic approach, we identified L3MBTL3 as a novel interactor of RBPJ. We discovered that L3MBTL3 competes with NOTCH ICD for binding to RBPJ. In the absence of NOTCH ICD, RBPJ recruits L3MBTL3 and its co-factor KDM1A [lysine (K)-specific demethylase 1A] to the promoters/enhancers of Notch target genes to promote H3K4me2 demethylation and transcriptional repression. In three distinct cell contexts in which Notch signaling governs cell fate, i.e., mature T-cells as well as brain and breast tumor cells, the loss of L3MBTL3 results in the de-repression of Notch target genes. Finally, the genetic analyses of the homologs of RBPJ and L3MBTL3 in Drosophila melanogaster and Caenorhabditis elegans demonstrate that the functional link between RBPJ/Su(H)/lag-1 and L3MBTL3/dL(3)mbt/lin-61 is evolutionarily conserved, thus identifying L3MBTL3 as a universal modulator of Notch signaling in metazoans.