Project description:Transcription profiling by array of striatal tissue of wild type and Ezh1/Ezh2 double knockout mice at 6 weeks, 3 months, and 6 months
Project description:We analyzed the genomic distribution of H3K27me3 in a clone of c-Myc iMEFs (clone C2) either i) wild-type for Ezh2, ii) in the presence of overexpressed exogenous Ezh2, iii) Ezh2-mutant, and iv) Ezh1/Ezh2 pre-deletion (Ezh1/Ezh2 introduced before deletion of endogenous Ezh2) and Ezh2 post-deletion rescue (Ezh2 re-introduced in Ezh2-mutant cells).
Project description:Chromatin immunoprecipitation and sequencing for 3 histone marks (H3K27ac, H3K27me3 and H3K4me1) was performed on livers of male and female mice with a combined loss of Ezh1 and Ezh2. The DKO mouse model used in these analyses is a global deletion of Ezh1 and hepatocyte-specific deletion of Ezh2, and is described in Bae WK et al, FASEB J. 2015 May;29(5):1653-62. doi: 10.1096/fj.14-261537. PMID: 25477280.
Project description:Polycomb group (PcG) proteins initiate the formation of repressed chromatin domains and regulate developmental gene expression. A mammalian PcG protein, Enhancer of Zeste homolog 2 (Ezh2), triggers transcriptional repression by catalyzing the addition of methyl groups onto lysine-27 of histone H3 (H3K27me2/3)1. This action facilitates the binding of other PcG proteins to histone H3 and compaction of chromatin. Interestingly, there exists a paralog of Ezh2, termed Ezh1, whose primary function remains unclear. Here, we provide evidence for genome-wide association of Ezh1 with active epigenetic marks, RNA polymerase II (PolII) and mRNA production. Ezh1 depletion reduced global PolII occupancy within gene bodies and resulted in delayed transcriptional activation during differentiation of skeletal muscle cells. Conversely, ectopic expression of wild-type Ezh1 led to premature gene activation and rescued PolII-elongation defects in Ezh1-depleted cells. Collectively, these findings reveal an unanticipated role of a PcG protein in promoting mRNA transcription. Examination of 3 different histone modifications, 3 modified forms of RNA polymerase II, Ezh1, Ezh2 and mRNA levels in a skeletal muscle cells at various developmental stages.
Project description:PolyA-selected RNA isolated from livers of adult male and female mice with a combined loss of EZH1 and EZH2 in hepatocytes was analyzed by RNA-seq. The DKO mouse model used in these analyses is a global deletion of Ezh1 and hepatocyte-specific deletion of Ezh2, and is described in Bae WK, Kang K, Yu JH, Yoo KH, Factor VM, Kaji K, Matter M, Thorgeirsson S, Hennighausen L. FASEB J. 2015 May;29(5):1653-62. doi: 10.1096/fj.14-261537. PMID: 25477280
Project description:RNA-seq for DKO, E1KO, E2KO and WT E12.5 heart revealed that EZH1 and EZH2 play a partially redundant role to trimethylate histone H3 at Lys 27 (H3K27me3). Through EZH1, H3K27me3 and H3K27ac ChIP-seq and RNA-seq for P13 EZH1 and GFP overexpressing heart (AAVEzh1 and AAVGFP respectively) suffered MI at P10, we surprisingly found that EZH1 can active the expression of regenerating relevant genes by directly binding to the promoter of targeted genes and through a mechanism independent of H3K27me3 deposition. Together, we unravel a requirement but divergent mechanisms of EZH1 in heart development and regeneration
Project description:Polycomb group (PcG) proteins initiate the formation of repressed chromatin domains and regulate developmental gene expression. A mammalian PcG protein, Enhancer of Zeste homolog 2 (Ezh2), triggers transcriptional repression by catalyzing the addition of methyl groups onto lysine-27 of histone H3 (H3K27me2/3)1. This action facilitates the binding of other PcG proteins to histone H3 and compaction of chromatin. Interestingly, there exists a paralog of Ezh2, termed Ezh1, whose primary function remains unclear. Here, we provide evidence for genome-wide association of Ezh1 with active epigenetic marks, RNA polymerase II (PolII) and mRNA production. Ezh1 depletion reduced global PolII occupancy within gene bodies and resulted in delayed transcriptional activation during differentiation of skeletal muscle cells. Conversely, ectopic expression of wild-type Ezh1 led to premature gene activation and rescued PolII-elongation defects in Ezh1-depleted cells. Collectively, these findings reveal an unanticipated role of a PcG protein in promoting mRNA transcription.
Project description:Epigenetic mark deposition during embryonic development contribute to postnatal homeostasis and tissue stability. Previously, we found out that Ezh2 contributes critically to the function and postnatal cell survival in bipolar cells but not in retinal ganglion cells in the retina. (Yan et al. Postnatal onset of retinal degeneration by loss of embryonic Ezh2 repression of Six1. Sci Report. doi:10.1038/srep33887; (Cheng L, Wong LJ, Yan N, Han RC et al. Ezh2 does not mediate retinal ganglion cell homeostasis or their susceptibility to injury. PLoS One 2018;13(2):e0191853.). In this study, we used RNA-seq to define up- and down regulated genes in both Ezh2 and G9a deficient (Math5Cre; Ezh2f/fG9af/+; dKO) retinal ganglion cells (RGC) to evaluate the hypothesis of Ezh2 and G9a interaction that has been discussed in other tissues but in the retina. ChIP-Seq was applied to evaluate H3K27me3 histone marks in retinal ganglion cells in wild type (WT), Ezh2 (Math5Cre; Ezh2-/-, sKO) and combined G9a-Ezh2 (Math5Cre; G9a+/-Ezh2-/-, dKO) knockout mutant mice at P1.
Project description:Establishment and differentiation of mammary alveoli during pregnancy are controlled by prolactin through the transcription factor STAT5. As pregnancy progresses mammary signature genes are activated in a defined temporal order, which coincides with the recruitment of STAT5 to respective regulatory sequences. This study addressed the question whether the methyltransferase and transcriptional co-activator EZH2 controls the differentiation clock of mammary epithelium. Ablation of Ezh2 from mammary stem cells resulted in precocious differentiation of alveolar epithelium and accelerated activation of mammary signature genes. This coincided with enhanced occupancy by EZH1, Pol II and STAT5 to mammary-specific loci. Notably, loss of EZH2 did not result in overt changes in genome-wide and gene-specific H3K27me3 patterns, suggesting that enhanced EZH1 recruitment can compensate for the loss of EZH2. However, differentiated mammary epithelia failed to form in the combined absence of EZH1 and EZH2. Transplantation experiments failed to demonstrate a role for EZH2 in the biology of mammary stem and progenitor cells. In summary, while EZH1 and EZH2 serve redundant functions in the establishment of H3K27me3 and formation of mammary alveoli, the presence of EZH2 is required to obtain controlled temporal differentiation of mammary epithelium. ChIP-seq EZH1, EZH2, PolIII; WT and E2KO mammary cells
Project description:Although epigenetic mechanisms, such as specific histone modifications, control common and cell-specific genetic programs, a role for histone modifying enzymes in liver metabolism and disease has not been investigated. This report demonstrates that the combined loss of the histone methyltransferases EZH1 and EZH2 in mouse hepatocytes led to the disruption of H3K27me3 homeostasis by age three months, simple fatty liver by age six months and fatal fibrosis by age 15 months. Global and gene-specific reduction of H3K27me3 marks paralleled a concomitant increase of H3K4me3 marks at genes associated with chronic liver disease. Advanced disease was accompanied by widespread infiltration of immune cells, an increase of activated hepatic stellate cells and collagen deposition. Expression of genes from the cytochrome P450 family that control drug metabolism was already deregulated by age two months and mice were fatally hypersensitive to carbon tetrachloride (CCl4). These genetic experiments, for the first time, illustrate that the simple loss of EZH1/EZH2, which results in the disruption of epigenetic modifications, is sufficient for the progression of fatal liver disease. RNA-seq and ChIP-seq were performed in liver tissues.