Project description:In this study, we have studied the genes associated with PRMT5 mediated histone methylation (H2R2me2s) in Th1-like iTregs. This particular epigenetic markers is upregulated in Th1 cells, and Th1-like iTregs. Therefore, we wanted to identify the genes H3R2me2s is regulating in Th1-like iTregs as compared to iTregs or Th1 cells. The goal of this sequencing was to identify if H2R2me2s is important for increased suppressive capacity of Th1-like iTregs or not.
Project description:Symmetrical dimethylation on arginine-3 of histone H4 (H4R3me2s) has been reported to occur at several repressed genes, but its specific regulation and genomic distribution remained unclear. Here, we show that the type-II protein arginine methyltransferase PRMT5 controls H4R3me2s in mouse embryonic fibroblasts (MEFs). In these differentiated cells, we find that the genome-wide pattern of H4R3me2s is highly similar to that in embryonic stem cells. In both the cell types, H4R3me2s peaks are detected predominantly at G + C-rich regions. Promoters are consistently marked by H4R3me2s, independently of transcriptional activity. Remarkably, H4R3me2s is mono-allelic at imprinting control regions (ICRs), at which it marks the same parental allele as H3K9me3, H4K20me3 and DNA methylation. These repressive chromatin modifications are regulated independently, however, since PRMT5-depletion in MEFs resulted in loss of H4R3me2s, without affecting H3K9me3, H4K20me3 or DNA methylation. Conversely, depletion of ESET (KMT1E) or SUV420H1/H2 (KMT5B/C) affected H3K9me3 and H4K20me3, respectively, without altering H4R3me2s at ICRs. Combined, our data indicate that PRMT5-mediated H4R3me2s uniquely marks the mammalian genome, mostly at G + C-rich regions, and independently from transcriptional activity or chromatin repression. Furthermore, comparative bioinformatics analyses suggest a putative role of PRMT5-mediated H4R3me2s in chromatin configuration in the nucleus. High throughput sequencing data from H4R3me2s native ChIP samples from mouse embryonic stem cells and fibroblasts were generated using Illumina Hi-seq 2000.
Project description:Protein arginine methyltransferase 5 (PRMT5) catalyzes the symmetric di-methylation of arginine residues in histones H3 and H4, marks generally associated with transcriptional repression. However, we found that PRMT5 inhibition (or depletion) led to more genes being down-regulated than up-regulated, indicating that PRMT5 can also act as a transcriptional activator. Indeed, the global level of histone H3K27me3 increases in PRMT5 deficient cells. Although PRMT5 does not directly affect PRC2 enzymatic activity, methylation of histone H3 by PRMT5 abrogates its subsequent methylation by PRC2. Treating AML cells with an EZH2 inhibitor partially restored the expression of approximately 50% of the genes that are initially down-regulated by PRMT5 inhibition, suggesting that the increased H3K27me3 contributes to the transcription repression of these genes. Interestingly, the growth inhibitory effect of PRMT5 inhibition was also partially rescued by combined treatment with EZH2 inhibitor in several leukemia cell lines. Thus, PRMT5-mediated crosstalk between histone marks contributes to its functional effects.
Project description:This study aimed to clarify the role of PRMT5 in the hematopoietic stem cell (HSC) compartment, and elucidate the functional relevance of PRMT5-mediated splicing in HSCs. We confirm the cell intrinsic requirement for PRMT5 in HSC maintenance, and present evidence suggesting that PRMT5 deficiency perturbs HSC proteostasis. Notably, we also uncover a critical role for PRMT5 in maintaining HSC genomic integrity by modulating splicing of genes involved in DNA repair; loss of which leads to unresolved DNA damage, p53 activation and rapid HSC exhaustion. Overall, these findings establish PRMT5-mediated splicing as a major determinant of HSC fate, and highlight the need to maintain an adequate level of PRMT5 activity in HSCs.
Project description:Protein arginine methyltransferase 5 (PRMT5) catalyzes the symmetric di-methylation of arginine residues in histones H3 and H4, marks generally associated with transcriptional repression. However, we found that PRMT5 inhibition (or depletion) led to more genes being down-regulated than up-regulated, indicating that PRMT5 can also act as a transcriptional activator. Indeed, the global level of histone H3K27me3 increases in PRMT5 deficient cells. Although PRMT5 does not directly affect PRC2 enzymatic activity, methylation of histone H3 by PRMT5 abrogates its subsequent methylation by PRC2. Treating AML cells with an EZH2 inhibitor partially restored the expression of approximately 50% of the genes that are initially down-regulated by PRMT5 inhibition, suggesting that the increased H3K27me3 contributes to the transcription repression of these genes. Interestingly, the growth inhibitory effect of PRMT5 inhibition was also partially rescued by combined treatment with EZH2 inhibitor in several leukemia cell lines. Thus, PRMT5-mediated crosstalk between histone marks contributes to its functional effects.
Project description:This SuperSeries is composed of the following subset Series:; GSE11533: Autoregulation of Th1-mediated inflammation by twist1 1st part; GSE11534: Autoregulation of Th1-mediated inflammation by twist1 2nd part Experiment Overall Design: Refer to individual Series
Project description:This study provides evidence on the molecular mechanisms by which P2RX7 signaling promotes Th1 cell differentiation. P2RX7 induces T-bet expression and aerobic glycolysis in splenic CD4+ T cells that respond to malaria, at a time prior to Th1/Tfh polarization. Cell-intrinsic P2RX7 signaling sustains the glycolytic pathway and causes bioenergetic mitochondrial stress in activated CD4+ T cells. We also show in vitro the phenotypic similarities of Th1-polarized CD4+ T cells that do not express P2RX7 and those in which the glycolytic pathway is pharmacologically inhibited. In addition, ATP synthase blockade in vitro and the consequent inhibition of oxidative phosphorylation, which forces cells to use aerobic glycolysis, is sufficient to promote rapid CD4+ T cell proliferation and polarization to the Th1 profile in the absence of P2RX7. These data demonstrate that P2RX7-mediated metabolic reprograming for aerobic glycolysis is a key event for Th1 cell differentiation and suggest that ATP synthase inhibition is a fundamental mechanism by which P2X7 signaling induces the Th1 response.
Project description:Patients suffering from chronic lymphocytic leukemia (CLL) display highly diverse clinical courses ranging from indolent cases to aggressive disease with genetic and epigenetic features resembling this diversity. Here, we developed a comprehensive approach combining a variety of molecular and clinical data to identify translocation events disrupting long-range chromatin interactions and causing cancer-relevant transcriptional deregulation. Thereby, we identified a B cell specific cis-regulatory element restricting the expression of genes in the associated locus, including PRMT5 and DAD1, two factors with oncogenic potential. Examining the role of PRMT5 in CLL identified transcriptional programs associated with pathways of stress tolerance and growth support, maintaining MYC-driven gene expression in vivo and in vitro. Conversely, inhibition of PRMT5 impairs factors involved in DNA-repair and sensitizes cells for apoptosis. Finally, we show that artificial deletion of the regulatory element from its endogenous context resulted in upregulation of corresponding genes, including PRMT5. Furthermore, such disruption renders PRMT5 transcription vulnerable to additional stimuli and subsequently also alters the expression of downstream PRMT5 targets.
Project description:CD4+ T cell differentiation into multiple T helper lineages is critical for optimal adaptive immune responses. This report identified a novel intrinsic mechanism by which PD-1 signaling imparted regulatory phenotype to FoxP3+ Th1 cells (denoted as Tbet+iTregPDL1 cells) and iTregs. Tbet+iTregPDL1 cells were capable of preventing inflammation in murine models of experimental colitis and experimental graft versus host disease. PDL-1 binding to PD-1 imparted regulatory function to Tbet+iTregPDL1 cells and iTregs by specifically downregulating an endolysosomal protease asparaginyl endopeptidase (AEP) AEP regulated FoxP3 stability and blocking AEP imparted regulatory function in Tbet+iTregs cells. Also AEP-/- iTregs significantly inhibited GvHD and maintained FoxP3. Furthermore, PD-1 mediated FoxP3 maintenance in Tbet+Th1 cells occurred both in tumor infiltrating lymphocytes (TIL) and during chronic viral infection. Collectively, this report has identified a novel intrinsic function for PD-1 in converting Th1 cells into Tregs through an intrinsic proteolytic pathway