Project description:The de novo DNA methyltransferase 3-like (Dnmt3L) is a catalytically inactive DNA methylase that has been previously shown to cooperate with Dnmt3a and Dnmt3b to methylate DNA. Dnmt3L is highly expressed in mouse embryonic stem cells (ESC) but its function in these cells is unknown. We here report that Dnmt3L is required for the differentiation of ESC into primordial germ cells (PGC) through activation of the homeotic gene Rhox5. By genome-wide analysis we found that Dnmt3L is a positive regulator of methylation at gene bodies of housekeeping genes and a negative regulator of methylation at promoters of bivalent genes. We demonstrate that Dnmt3L interacts with the Polycomb PRC2 complex in competition with the DNA methyl transferases Dnmt3a and Dnmt3b to maintain low the methylation level at H3H27me3 regions. Thus in ESC, Dnmt3L counteracts the activity of de novo DNA methylases to keep low the level of DNA methylation at developmental gene promoters. Total RNA extracted from shGFP or shDnmt3L (three different) embryonic stem cells. A duplicate was performed for each point. Cells were transfected with shRNA and selected with Puromicin for 3 days before RNA extraction
Project description:The de novo DNA methyltransferase 3-like (Dnmt3L) is a catalytically inactive DNA methylase that has been previously shown to cooperate with Dnmt3a and Dnmt3b to methylate DNA. Dnmt3L is highly expressed in mouse embryonic stem cells (ESC) but its function in these cells is unknown. We here report that Dnmt3L is required for the differentiation of ESC into primordial germ cells (PGC) through activation of the homeotic gene Rhox5. By genome-wide analysis we found that Dnmt3L is a positive regulator of methylation at gene bodies of housekeeping genes and a negative regulator of methylation at promoters of bivalent genes. We demonstrate that Dnmt3L interacts with the Polycomb PRC2 complex in competition with the DNA methyl transferases Dnmt3a and Dnmt3b to maintain low the methylation level at H3H27me3 regions. Thus in ESC, Dnmt3L counteracts the activity of de novo DNA methylases to keep low the level of DNA methylation at developmental gene promoters. Examination of 5mC in shGFP and shDnmt3L ESC by MeDIP-Seq
Project description:Embryonic stem cells (ESC) are derived from blastocyst-stage embryos and are thought to be functionally equivalent to the inner cell mass in their developmental potential. ESCs pluripotency is maintained through a complex interplay of different signaling pathways and a network of transcription factors, which is centered around Oct3/4, Sox2 and Nanog. Although, in general, much is known about this pluripotency self-renewal circuitry, the molecular events that lead ESC to exit from pluripotency and begin differentiation are currently less known. Retinoic acid, an active metabolite of the vitamin A (retinol), plays important and pleiotropic roles in vertebrate embryonic development and ESC differentiation. Here we demonstrate that RA promotes early steps of ESC differentiation, and that ESC increase their capacity to synthesize RA during spontaneous differentiation as embryoid bodies, up-regulating the RA biosynthetic pathway components RDH1, RDH10, ADH3, RALDH2, and CRABP2. Microarray derived from total RNA of mESC not treated or treated with all-trans retinoic acid (ATRA) for 2 hours.
Project description:Although much is known about the pluripotency self-renewal circuitry, the molecular events that lead embryonic stem cells (ESCs) exit from pluripotency and begin differentiation are largely unknown. We found that the zinc finger transcription factor Snai1, involved in gastrulation and epithelial- mesenchymal transition (EMT) is already expressed in the inner cell mass of the preimplantation blastocysts. In ESCs Snai1 does not respond to TGFα or BMP4 signalling but it is induced by retinoic acid (RA) treatment, which induces the binding, on the Snai1 promoter, of the retinoid receptors RARγ and RXRα the dissociation of the Polycomb repressor compex 2 (PRC2) which results in the decrease of H3K27me3 and the increase of histone H3K4me3. Snai1 mediates the repression of pluripotency genes by binding directly to the promoters of Nanog, Nr5a2, Tcl1, c-Kit, and Tcfcp2l1. The transient activation of Snai1 in embryoid bodies induces the expression of the markers of all three germ layers. These results suggest that Snai1 is a key factor that triggers ESCs exit from the pluripotency state and initiate their differentiation processes. microarray analysis of embryonic stem cells (ESC) expressing Snail-ER at various time points of induction with 4-OHT
Project description:Recent studies have analyzed the distribution and role of 5-hydroxymethylcytosin (5hmC) in Embryonic Stem Cells (ESC). However, DNA hydroxymethylation occurs also in differentiated cells and it is significantly deregulated in cancer. Here we mapped 5hmC genome-wide profile in pluripotent ES cells in comparison to embryonic and adult differentiated cells. Comparative analysis of 5hmC genomic distribution with respect to gene expression reveals that 5hmC is enriched on the gene body of genes expressed at medium/high level and on TSS of genes not expressed or expressed at low level independently from the cell type. ESC showed a significant enrichment of DNA hydroxymethylation in active enhancers and bivalent promoters with respect to more differentiated cells as well as preferential association of Tet1 and 5hmC with promoter bound by Polycomb Repressive Complex 2 (PRC2). Furthermore, we show that in ESC PRC2 interacts with Tet1 and it is required for Tet1 recruitment to the chromatin and 5hmC deposition at developmental genes. Examination of 5hmC in ESC, MEF, Brain, Liver, shGFP ESC, and shSuz12ESC, and examination of expression in shGFP ESC and shSuz12ESC.
Project description:5-hydroxymethylcytosine (5hmC) is a recently discovered epigenetic modification that is lost in human cancers. Formation of 5hmC is catalysed by the Ten eleven translocation (TET) proteins that mediate the sequential oxidation of 5-methylcytosine (5mC) to 5hmC, leading to eventual DNA demethylation. Several mechanisms can lead to loss of 5hmC in cancers, including mutations in IDH or TET2 genes. However, little is known about the role of TET proteins and 5hmC in adult cells. Here, we report that TET1 downmodulation is required to permit adult cells to proliferate. TET1 is rapidly downmodulated in proliferating primary cells and in regenerating liver. TET1 silencing accelerates cell cycle progression while its constitutive expression inhibits cell growth. TET1 is a negative regulator of cell proliferation and it is regulated during development in tissue specific manner. These findings enlarge our knowledge on how one epigenetic modification such as the DNA hydroxymethylation mediated by TET1 is a key player on the control of cell proliferation. Examination of 5hmC in MEF at passage 0 and at passage 5.
Project description:Each of 70 cell samples either at the control condition or treated with FDA-approved cancer drugs is sequenced by the single-ended random-primed mRNA-sequencing method with a read length of 100 base pairs, and a total of 70 raw sequence data files in the FASTQ format are generated. These sequence data files are then analyzed by a high-performance computational pipeline and ranked lists of gene signatures and biological processes related to drug-induced cardiotoxicity are generated for each drug. The raw sequence datasets and the analysis results have been carefully controlled for data quality, and they are made publicly available at the Gene Expression Omnibus (GEO) database repository of NIH. As such, this broad drug-stimulated transcriptomi dataset is valuable for the prediction of drug toxicities and their mitigations.
Project description:Each of 914 cell samples either at the control condition or treated with FDA-approved cancer drugs is sequenced by the single-ended 3'-DGE mRNA-sequencing method with a read length of 46 base pairs, and a total of 914 raw sequence data files in the FASTQ format are generated. These sequence data files are then analyzed by a high-performance computational pipeline and ranked lists of gene signatures and biological processes related to drug-induced cardiotoxicity are generated for each drug. The raw sequence datasets and the analysis results have been carefully controlled for data quality, and they are made publicly available at the Gene Expression Omnibus (GEO) database repository of NIH. As such, this broad drug-stimulated transcriptomi dataset is valuable for the prediction of drug toxicities and their mitigations.
Project description:Olfactory ensheathing cells are one of the few central nervous system regenerative cells discovered so far. It is characterized by its lifelong nerve regeneration function, and it can also release a variety of neurotrophic factors and neural adhesion molecules. It is considered to be the glial cell with the strongest myelination ability. Olfactory ensheathing cells and Schwann cells have phenotypes in common, they can promote axon regeneration(R. Doucette, 1995). Olfactory ensheathing cells have the characteristics of Schwann cells and astrocytes, but the overall performance tends to be the former, which has two unique characteristics. First, it exists not only in the peripheral nerves (Schwann cells), but also in the central nervous system (astroglia); second, the olfactory mucosa has the ability to regenerate life-long, including human olfactory ensheathing cells(J. C. Bartolomei and C. A. Greer, 2000). Regeneration is a process in which olfactory ensheathing cells participate in efficient regulation, although the specific mechanism is not yet clear. Olfactory ensheathing cells are different from astrocytes and Schwann cells, but at the same time have the characteristics of these two cells(S. C. Barnett, 2004), like Schwann cells help axon growth, but more than Schwann cells It can make axons grow long distances, that is, it has stronger migration(A. Ramon-Cueto et al., 1998); there are also astrocytes that have a nutritional effect on the survival of neurons and the growth of axons, but olfactory ensheathing cells can also wrap neurons forms myelin sheath to support the growth of nerve processes(R. Devon and R. Doucette, 1992; J. Gu et al., 2019). There are two characteristics that make olfactory ensheathing cells the best choice for the treatment of neurological diseases(S. C. Chiu et al., 2009; J. Kim et al., 2018; M. Abdel-Rahman et al., 2018). Olfactory ensheathing cells are gradually used to treat spinal cord injuries and have shown amazing effects(J. C. Bartolomei and C. A. Greer, 2000; K. J. Liu et al., 2010; R. Yao et al., 2018). Olfactory ensheathing cells that have been used in research are usually derived from the olfactory bulb(E. H. Franssen et al., 2007), but it is easier to obtain olfactory ensheathing cells from the olfactory mucosa in clinical practice(M. Ryszard et al., 2006), so the difference between the olfactory ensheathing cells from the olfactory bulb and the olfactory mucosa There are more and more studies(B. M. U. et al., 2007), and previous studies have shown that they not only have many similar functions, but also have many differences(M. W. Richter et al., 2005; L. Wang et al., 2014; K. E. Smith et al., 2020). Because olfactory ensheathing cells derived from the olfactory bulb are not easy to obtain, olfactory ensheathing cells derived from the olfactory mucosa have become the focus of attention. Although we know that olfactory ensheathing cells from two sources have nerve repair functions, it is not clear why the two different sources of olfactory ensheathing cells have different therapeutic effects. Nicolas G. once studied that the genetic difference between the two cells and found that there are many genes related to wound repair and nerve regeneration(G. Nicolas et al., 2010). We have reason to guess that olfactory ensheathing cells from these two sources will also have a large difference in protein level. Our research group wants to use the current mature transcriptome and proteomic sequencing technologies to explore the difference between olfactory ensheathing cells from the olfactory bulb and olfactory mucosa, and explain why the two sources of olfactory ensheathing cells shows different therapeutic effects, hope to provide a new theoretical basis for future clinical treatment.
Project description:Background: Microorganisms are the major cause of food spoilage during storage, processing and distribution. Pseudomonas fluorescens is a typical spoilage bacterium that contributes to a large extent to the spoilage process of proteinaceous food. RpoS is considered an important global regulator involved in stress survival and virulence in many pathogens. Our previous work revealed that RpoS contributed to the spoilage activities of P. fluorescens by regulating resistance to different stress conditions, extracellular acylated homoserine lactone (AHL) levels, extracellular protease and total volatile basic nitrogen (TVB-N) production. However, RpoS-dependent genes in P. fluorescens remained undefined. Results: RNA-seq transcriptomics analysis combined with quantitative proteomics analysis basing on multiplexed isobaric tandem mass tag (TMT) labeling was performed for the P. fluorescens wild-type strain UK4 and its derivative carrying a rpoS mutation. A total of 375 differentially expressed genes (DEGs) and 212 differentially expressed proteins (DEPs) were identified in these two backgrounds. The DGEs were further verified by qRT-PCR tests, and the genes directly regulated by RpoS were confirmed by 5’-RACE-PCR sequencing. The combining transcriptome and proteome analysis revealed a role of this regulator in several cellular processes, including polysaccharide metabolism, intracellular secretion and extracellular structures, cell well biogenesis, stress responses, ammonia and biogenic amine production, which may contribute to biofilm formation, stress resistance and spoilage activities of P. fluorescens. Moreover, in this work we indeed observed that RpoS contributed to the production of the macrocolony biofilm’s matrix.