Knockdown and Overexpression of Cbx4 wild type, Cbx4 chromodomain mutant, and Cbx4 sumoylation mutant in human epidermal stem cells
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ABSTRACT: This SuperSeries is composed of the following subset Series: GSE31093: Knockdown and Overexpression of Cbx4 wild type and of a Cbx4 chromodomain mutant in human epidermal stem cells GSE31094: Overexpression of Cbx4 wild type and of a Cbx4 sumoylation mutant in human epidermal stem cells Refer to individual Series
Project description:Human epidermal stem cells transit from a slow cycling to an actively proliferating state to contribute to homeostasis. Both stem cell states differ in their cell cycle profiles but must remain guarded from differentiation and senescence. Here we show that Cbx4, a Polycomb Repressive Complex-1 (PRC1)-associated protein, maintains human epidermal stem cells slow-cycling and undifferentiated, while protecting them from senescence. Interestingly, abrogating the polycomb activity of Cbx4 impairs its anti-senescent function without affecting stem cell differentiation, indicating that differentiation and senescence are independent processes in human epidermis. Conversely, Cbx4 inhibits stem cell activation and differentiation through its SUMO ligase activity. Global transcriptome and chromatin occupancy analyses indicate that Cbx4 regulates modulators of epidermal homeostasis and represses factors, such as Ezh2, Dnmt1, and Bmi1, to prevent the activate stem cell state. Our results suggest that distinct Polycomb complexes balance epidermal stem cell dormancy and activation, while continually preventing senescence and differentiation. Primary human keratinocytes were infected with control vector pBABE, Cbx4 wildtype and a chromodomain mutant version of Cbx4 (F11A and W35L), both fused to a Estrogen Receptor to render their activaty inducible by addition of 4OHT to the media. Cells were cultured for 5 days (after infection and selection) under 4OHT treatment, after which total RNA was collected. For the knockdown, the pRetroSuperPuro was used as a control vector, in which a shRNA sequence for Cbx4 was introduced to interfere with Cbx4 expression. Cell were cultured in the same way as for the overexpression experiments.
Project description:Human epidermal stem cells transit from a slow cycling to an actively proliferating state to contribute to homeostasis. Both stem cell states differ in their cell cycle profiles but must remain guarded from differentiation and senescence. Here we show that Cbx4, a Polycomb Repressive Complex-1 (PRC1)-associated protein, maintains human epidermal stem cells slow-cycling and undifferentiated, while protecting them from senescence. Interestingly, abrogating the polycomb activity of Cbx4 impairs its anti-senescent function without affecting stem cell differentiation, indicating that differentiation and senescence are independent processes in human epidermis. Conversely, Cbx4 inhibits stem cell activation and differentiation through its SUMO ligase activity. Global transcriptome and chromatin occupancy analyses indicate that Cbx4 regulates modulators of epidermal homeostasis and represses factors, such as Ezh2, Dnmt1, and Bmi1, to prevent the activate stem cell state. Our results suggest that distinct Polycomb complexes balance epidermal stem cell dormancy and activation, while continually preventing senescence and differentiation. Primary human keratinocytes were infected with control vector pBABE, Cbx4 wildtype and a Sumoylation mutant version of Cbx4 (the two Sumo Interaction Motifs were deleted), both fused to a Estrogen Receptor to render their activaty inducible by addition of 4OHT to the media. Cells were cultured for 5 days (after infection and selection) under 4OHT treatment, after which total RNA was collected.
Project description:We designed a custom microarray to profile the expression and used it to measure the expression of 9929 human lncRNAs manually-annotated by the GENCODE group as part of the ENCODE consortium. One microarray hybridisation per biological sample.
Project description:Surveying epidermal stem cell homeostais over a 45-hour time course 45h time course with 10 samples over triplicates (x2 Agilent arrays)
Project description:Activation-induced cytidine deaminase (AID) is essential for class switch recombination (CSR) and somatic hypermutation (SHM). Its deregulated expression acts as a genomic mutator that can contribute to the development of various malignancies. During treatment with imatinib mesylate (IM), patients with chronic myeloid leukemia (CML) often develop hypogammaglobulinemia, the mechanism of which has not yet been clarified. Here, we provide evidence that CSR upon B cell activation is apparently inhibited by IM through downregulation of AID. Furthermore, expression of E2A, a key transcription factor for AID induction, was markedly suppressed by IM. These results elucidate not only the underlying mechanism of IM-induced hypogammaglobulinemia but also its potential efficacy as an AID suppressor. We investigated that class switch recombination(CSR) upon B cell activation is apparently inhibited by imatinib mesylate(IM) through downregulation of activation-induced cytidine deaminase(AID). Furthermore, expression of E2A was markedly suppressed by IM. To elucidate the more detailed pathway, we performed the microarray analysis. Microarray analysis was performed on splenocytes cultured for 72 h in the presence or absence of 10 µM Imatinib. The mouse splenocytes were cultured for 72 h with or without 10 µM Imatinib (IM) in conditioning medium containing IL-4 and LPS. RNA from 1X10^6 splenocytes used for microarray analysis was isolated using the RNeasy Mini Kit (50) (Qiagen, Hilden, Germany). Gene expression microarray analysis was performed using one-color microarray-based gene-expression analysis (Agilent Technologies, Santa Clara, CA, USA) according to the manufacturer’s instructions. After scanning, expression values for the genes were determined using GeneSpringGX software.
Project description:A major challenge in Down syndrome (DS) is to understand how the extra-dose of functional chromosome 21 (HSA21) genetic elements can impact on the tissue-specific transcriptome to contribute to phenotypic alterations. MiRNAs are post-transcriptional modulators with genome-wide regulatory effects. Five microRNAs have been identified in HSA21 that are present in triple copy in DS individuals. Interestingly, in the Ts65Dn mouse model of DS two of these miRNAs, miR-155 and miR-802, are also triplicated resulting in its overexpression. In the current work, we have developed a lentiviral miRNA-sponge genetic strategy for miR-155 and miR-802 (Lv-miR155-802T) to identify novel mRNA targets involved in hippocampal function. Hippocampal injection of the lentiviral sponge in Ts65Dn mice reduced miR-155 and miR-802 overexpression. Noticeable lentiviral sponge rescued the expression of the miRNA predicted targets showing the potential of the strategy to identify miRNA dosage-sensitive genes with potential involvement in DS-hippocampal phenotypes. Euploid and trisomic adult mice were bilaterally injected at the level of the ventral hippocampus at selected coordinates (AP=-3.3mm, L=+/- 3mm, DV=-3.3mm and -2.3mm relative to bregma). Up to 108 transducing units (3µl of viral suspensions of Lv-Contol or Lv-miR155-802T) were injected into each hemisphere at a rate of 0.2 µl/min, under the precise control of an infusion pump (Ultramicropump, World Precision Instruments). Mice were euthanized for hippocampus collection at day 23 after administration. Transcriptome of hippocampus of euploid and trisomic mice treated with Lv-Control or Lv-miR155-802T was analysed using an Agilent SurePrint G3 Mouse gene expression 8x60K Microarray (ID 028005). A total RNA 100 ng, obtained using miRNeasy Mini Ki (QIAGEN), were labeled using LowInputQuick Amp Labeling kit (Agilent 5190-2305) following manufacturer instructions. Briefly, mRNA was reverse transcribed in the presence of T7-oligo-dT primer to produce cDNA. cDNA was then in vitro transcribed with T7 RNA polymerase in the presence of Cy3-CTP to produce labeled cRNA. The labeled cRNA was hybridized to the Agilent SurePrint G3 Mouse gene expression 8x60K Microarray (ID 028005) according to the manufacturer's protocol. The arrays were washed, and scanned on an Agilent G2565CA microarray scanner at 100% PMT and 3µm resolution. Intensity data was extracted using the Feature Extraction software (Agilent). Replicates from each genotypes and treatment group were distributed as follows: EU+Lv-Contol n=4, EU+Lv-miR155-802T n=4, TS+Lv-Contol n=5, TS+Lv-miR155-802T n=3.
Project description:Mouse models of intestinal crypt cell differentiation and tumorigenesis have been used to characterize the molecular mechanisms underlying both processes. DNA methylation is a key epigenetic mark and plays an important role in cell identity and differentiation programs and cancer. To get insights into the dynamics of cell differentiation and malignant transformation we have compared the DNA methylation profiles along the mouse small intestine crypt and early stages of carcinogenesis. Genome-scale analysis of DNA methylation together with microarray gene expression have been applied to compare intestinal crypt stem cells (EphB2positive), differentiated cells (EphB2negative), ApcMin/+ adenomas and the corresponding non-tumor adjacent tissue, together with small and large intestine samples and the colon cancer cell line CT26. Compared with late stages, small intestine crypt differentiation and early stages of carcinogenesis display few and relatively small changes in DNA methylation. Hypermethylated loci are largely shared by the two processes and affect the proximities of promoter and enhancer regions, with enrichment in genes regulated by PRC2 and associated with the intestinal stem cell signature. The hypermethylation is progressive, with minute levels in differentiated cells, as compared with intestinal stem cells, and reaching full methylation in advanced stages. Hypomethylation shows different signatures in differentiation and cancer and is already present in the non-tumor tissue adjacent to the adenomas in ApcMin/+mice, but at lower levels than advanced cancers. Taking into account the parallelisms between human and mouse intestinal carcinogenesis, this study provides a reference framework to interpret the alterations found in human cancer. We have analyzed ApcMin/+ adenomas and the corresponding non-tumor adjacent tissue, together with small and large intestine samples and the colon cancer cell line CT26. Samples were in triplicates, except for tissue adjacent to adenoma (in duplicates).
Project description:Neural development requires crosstalk between signaling pathways and chromatin. In this study, we demonstrate that neurogenesis is promoted by an interplay between the TGFM-NM-2 pathway and the H3K27me3 histone demethylase (HDM) JMJD3. Genome-wide analysis showed that JMJD3 is targeted to gene promoters by Smad3 in neural stem cells (NSCs) and is essential to activate TGFM-NM-2-responsive genes. In vivo experiments in chick spinal cord revealed that the generation of neurons promoted by Smad3 is dependent on JMJD3 HDM activity. Overall, these findings indicate that JMJD3 function is required for the TGFM-NM-2 developmental program to proceed Mouse neural stem cells (NSC) control and JMJD3 knock down (shctrl and shJMJD3) were treated with the vehicle (-TGFb) or TGFbeta 5ng/ml (+TGFb) for 2.5h. Three replicates were performed for each point. And all of them were use it to posterior analysis.
Project description:PHF8 is a histone demethylase associated with X-linked mental retardation (XLMR). It has been described as a transcriptional coactivator involved in cell cycle progression, but its physiological role is still poorly understood. Here we show that PHF8 controls the expression of genes involved in cell adhesion and cytoskeleton organization such as RhoA, Rac1 and GSK3M-NM-2. A lack of PHF8 not only results in a cell cycle delay but also in a disorganized actin cytoskeleton and impaired cell adhesion. Our data demonstrate that PHF8 directly regulates the expression of these genes by demethylating H4K20me1 at promoters. Moreover, c-Myc transcription factor interacts with PHF8 and binds to the analyzed promoters, suggesting that c-Myc is involved on PHF8 recruitment to these promoters. Further analysis in the neuroblastoma cell line SH-SY5Y and in cortical neurons shows that depletion of PHF8 results in deficient neurite elongation. Overall, our results suggest that the mental retardation phenotype associated with loss of function of PHF8 could be due to abnormal neuronal connections as a result of alterations in cytoskeleton function. HeLa cells were transfected with either control or PHF8 siRNAs. Experiments were performed in biological triplicates. RNA were extracted and sujected to microarray analysis.
Project description:Gene expression profile in control (shCTR) and Phf19 depleted (sh4) mouse embryonic stem cell untreated or treated 72 hr with 1 M-NM-<M retinoic acid (72 RA). 4 samples, each one contains four biological replicas, except for ES-sh4_72hr RA which contains 3 replicas