Life Sciences Research for Lifelong Health

Publications

The Babraham Institute Publications database contains details of all publications resulting from our research groups and scientific services.

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Title / Authors / Details Open Access Download

Correction: Epigenetic resetting of human pluripotency (doi:10.1242/dev.146811).
Guo G, von Meyenn F, Rostovskaya M, Clarke J, Dietmann S, Baker D, Sahakyan A, Myers S, Bertone P, Reik W, Plath K, Smith A

Development (Cambridge, England), 145, 1477-9129, , 2018

PMID: 29669738


Open Access

A Critical Role of TET1/2 Proteins in Cell-Cycle Progression of Trophoblast Stem Cells.
Chrysanthou S, Senner CE, Woods L, Fineberg E, Okkenhaug H, Burge S, Perez-Garcia V, Hemberger M

The ten-eleven translocation (TET) proteins are well known for their role in maintaining naive pluripotency of embryonic stem cells. Here, we demonstrate that, jointly, TET1 and TET2 also safeguard the self-renewal potential of trophoblast stem cells (TSCs) and have partially redundant roles in maintaining the epithelial integrity of TSCs. For the more abundantly expressed TET1, we show that this is achieved by binding to critical epithelial genes, notably E-cadherin, which becomes hyper-methylated and downregulated in the absence of TET1. The epithelial-to-mesenchymal transition phenotype of mutant TSCs is accompanied by centrosome duplication and separation defects. Moreover, we identify a role of TET1 in maintaining cyclin B1 stability, thereby acting as facilitator of mitotic cell-cycle progression. As a result, Tet1/2 mutant TSCs are prone to undergo endoreduplicative cell cycles leading to the formation of polyploid trophoblast giant cells. Taken together, our data reveal essential functions of TET proteins in the trophoblast lineage.

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Stem cell reports, , 2213-6711, , 2018

PMID: 29576538


Open Access

Identifying Human Naïve Pluripotent Stem Cells - Evaluating State-Specific Reporter Lines and Cell-Surface Markers.
Collier AJ, Rugg-Gunn PJ

Recent reports that human pluripotent stem cells can be captured in a spectrum of states with variable properties has prompted a re-evaluation of how pluripotency is acquired and stabilised. The latest additions to the stem cell hierarchy open up opportunities for understanding human development, reprogramming, and cell state transitions more generally. Many of the new cell lines have been collectively termed 'naïve' human pluripotent stem cells to distinguish them from the conventional 'primed' cells. Here, several transcriptional and epigenetic hallmarks of human pluripotent states in the recently described cell lines are reviewed and evaluated. Methods to derive and identify human naïve pluripotent stem cells are also discussed, with a focus on the uses and future developments of state-specific reporter cell lines and cell-surface proteins. Finally, opportunities and uncertainties in naïve stem cell biology are highlighted, and the current limitations of human naïve pluripotent stem cells considered, particularly in the context of differentiation.

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BioEssays : news and reviews in molecular, cellular and developmental biology, , 1521-1878, e1700239, 2018

PMID: 29574793


Open Access

Genome-wide Analyses Identify KIF5A as a Novel ALS Gene.
Nicolas A, Kenna KP, Renton AE, Ticozzi N, Faghri F, Chia R, Dominov JA, Kenna BJ, Nalls MA, Keagle P, Rivera AM, van Rheenen W, Murphy NA, van Vugt JJFA, Geiger JT, Van der Spek RA, Pliner HA, Shankaracharya , Smith BN, Marangi G, Topp SD, Abramzon Y, Gkazi AS, Eicher JD, Kenna A, , Mora G, Calvo A, Mazzini L, Riva N, Mandrioli J, Caponnetto C, Battistini S, Volanti P, La Bella V, Conforti FL, Borghero G, Messina S, Simone IL, Trojsi F, Salvi F, Logullo FO, D'Alfonso S, Corrado L, Capasso M, Ferrucci L, , Moreno CAM, Kamalakaran S, Goldstein DB, , Gitler AD, Harris T, Myers RM, , Phatnani H, Musunuri RL, Evani US, Abhyankar A, Zody MC, , Kaye J, Finkbeiner S, Wyman SK, LeNail A, Lima L, Fraenkel E, Svendsen CN, Thompson LM, Van Eyk JE, Berry JD, Miller TM, Kolb SJ, Cudkowicz M, Baxi E, , Benatar M, Taylor JP, Rampersaud E, Wu G, Wuu J, , Lauria G, Verde F, Fogh I, Tiloca C, Comi GP, Sorarù G, Cereda C, , Corcia P, Laaksovirta H, Myllykangas L, Jansson L, Valori M, Ealing J, Hamdalla H, Rollinson S, Pickering-Brown S, Orrell RW, Sidle KC, Malaspina A, Hardy J, Singleton AB, Johnson JO, Arepalli S, Sapp PC, McKenna-Yasek D, Polak M, Asress S, Al-Sarraj S, King A, Troakes C, Vance C, de Belleroche J, Baas F, Ten Asbroek ALMA, Muñoz-Blanco JL, Hernandez DG, Ding J, Gibbs JR, Scholz SW, Floeter MK, Campbell RH, Landi F, Bowser R, Pulst SM, Ravits JM, MacGowan DJL, Kirby J, Pioro EP, Pamphlett R, Broach J, Gerhard G, Dunckley TL, Brady CB, Kowall NW, Troncoso JC, Le Ber I, Mouzat K, Lumbroso S, Heiman-Patterson TD, Kamel F, Van Den Bosch L, Baloh RH, Strom TM, Meitinger T, Shatunov A, Van Eijk KR, de Carvalho M, Kooyman M, Middelkoop B, Moisse M, McLaughlin RL, Van Es MA, Weber M, Boylan KB, Van Blitterswijk M, Rademakers R, Morrison KE, Basak AN, Mora JS, Drory VE, Shaw PJ, Turner MR, Talbot K, Hardiman O, Williams KL, Fifita JA, Nicholson GA, Blair IP, Rouleau GA, Esteban-Pérez J, García-Redondo A, Al-Chalabi A, , Rogaeva E, Zinman L, Ostrow LW, Maragakis NJ, Rothstein JD, Simmons Z, Cooper-Knock J, Brice A, Goutman SA, Feldman EL, Gibson SB, Taroni F, Ratti A, Gellera C, Van Damme P, Robberecht W, Fratta P, Sabatelli M, Lunetta C, Ludolph AC, Andersen PM, Weishaupt JH, Camu W, Trojanowski JQ, Van Deerlin VM, Brown RH, van den Berg LH, Veldink JH, Harms MB, Glass JD, Stone DJ, Tienari P, Silani V, Chiò A, Shaw CE, Traynor BJ, Landers JE

To identify novel genes associated with ALS, we undertook two lines of investigation. We carried out a genome-wide association study comparing 20,806 ALS cases and 59,804 controls. Independently, we performed a rare variant burden analysis comparing 1,138 index familial ALS cases and 19,494 controls. Through both approaches, we identified kinesin family member 5A (KIF5A) as a novel gene associated with ALS. Interestingly, mutations predominantly in the N-terminal motor domain of KIF5A are causative for two neurodegenerative diseases: hereditary spastic paraplegia (SPG10) and Charcot-Marie-Tooth type 2 (CMT2). In contrast, ALS-associated mutations are primarily located at the C-terminal cargo-binding tail domain and patients harboring loss-of-function mutations displayed an extended survival relative to typical ALS cases. Taken together, these results broaden the phenotype spectrum resulting from mutations in KIF5A and strengthen the role of cytoskeletal defects in the pathogenesis of ALS.

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Neuron, 97, 1097-4199, 1268-1283.e6, 2018

PMID: 29566793


TDP-43 gains function due to perturbed autoregulation in a Tardbp knock-in mouse model of ALS-FTD.
White MA, Kim E, Duffy A, Adalbert R, Phillips BU, Peters OM, Stephenson J, Yang S, Massenzio F, Lin Z, Andrews S, Segonds-Pichon A, Metterville J, Saksida LM, Mead R, Ribchester RR, Barhomi Y, Serre T, Coleman MP, Fallon J, Bussey TJ, Brown RH, Sreedharan J

Amyotrophic lateral sclerosis-frontotemporal dementia (ALS-FTD) constitutes a devastating disease spectrum characterized by 43-kDa TAR DNA-binding protein (TDP-43) pathology. Understanding how TDP-43 contributes to neurodegeneration will help direct therapeutic efforts. Here we have created a TDP-43 knock-in mouse with a human-equivalent mutation in the endogenous mouse Tardbp gene. TDP-43mice demonstrate cognitive dysfunction and a paucity of parvalbumin interneurons. Critically, TDP-43 autoregulation is perturbed, leading to a gain of TDP-43 function and altered splicing of Mapt, another pivotal dementia-associated gene. Furthermore, a new approach to stratify transcriptomic data by phenotype in differentially affected mutant mice revealed 471 changes linked with improved behavior. These changes included downregulation of two known modifiers of neurodegeneration, Atxn2 and Arid4a, and upregulation of myelination and translation genes. With one base change in murine Tardbp, this study identifies TDP-43 misregulation as a pathogenic mechanism that may underpin ALS-FTD and exploits phenotypic heterogeneity to yield candidate suppressors of neurodegenerative disease.

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Nature neuroscience, , 1546-1726, , 2018

PMID: 29556029


Simulation Experiment Description Markup Language (SED-ML) Level 1 Version 3 (L1V3).
Bergmann FT, Cooper J, König M, Moraru I, Nickerson D, Le Novère N, Olivier BG, Sahle S, Smith L, Waltemath D

The creation of computational simulation experiments to inform modern biological research poses challenges to reproduce, annotate, archive, and share such experiments. Efforts such as SBML or CellML standardize the formal representation of computational models in various areas of biology. The Simulation Experiment Description Markup Language (SED-ML) describes what procedures the models are subjected to, and the details of those procedures. These standards, together with further COMBINE standards, describe models sufficiently well for the reproduction of simulation studies among users and software tools. The Simulation Experiment Description Markup Language (SED-ML) is an XML-based format that encodes, for a given simulation experiment, (i) which models to use; (ii) which modifications to apply to models before simulation; (iii) which simulation procedures to run on each model; (iv) how to post-process the data; and (v) how these results should be plotted and reported. SED-ML Level 1 Version 1 (L1V1) implemented support for the encoding of basic time course simulations. SED-ML L1V2 added support for more complex types of simulations, specifically repeated tasks and chained simulation procedures. SED-ML L1V3 extends L1V2 by means to describe which datasets and subsets thereof to use within a simulation experiment.

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Journal of integrative bioinformatics, , 1613-4516, , 2018

PMID: 29550789


Synthetic Biology Open Language Visual (SBOL Visual) Version 2.0.
Cox RS, Madsen C, McLaughlin J, Nguyen T, Roehner N, Bartley B, Bhatia S, Bissell M, Clancy K, Gorochowski T, Grünberg R, Luna A, Le Novère N, Pocock M, Sauro H, Sexton JT, Stan GB, Tabor JJ, Voigt CA, Zundel Z, Myers C, Beal J, Wipat A

People who are engineering biological organisms often find it useful to communicate in diagrams, both about the structure of the nucleic acid sequences that they are engineering and about the functional relationships between sequence features and other molecular species. Some typical practices and conventions have begun to emerge for such diagrams. The Synthetic Biology Open Language Visual (SBOL Visual) has been developed as a standard for organizing and systematizing such conventions in order to produce a coherent language for expressing the structure and function of genetic designs. This document details version 2.0 of SBOL Visual, which builds on the prior SBOL Visual 1.0 standard by expanding diagram syntax to include functional interactions and molecular species, making the relationship between diagrams and the SBOL data model explicit, supporting families of symbol variants, clarifying a number of requirements and best practices, and significantly expanding the collection of diagram glyphs.

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Journal of integrative bioinformatics, , 1613-4516, , 2018

PMID: 29549707


Comparison of whole-genome bisulfite sequencing library preparation strategies identifies sources of biases affecting DNA methylation data.
Olova N, Krueger F, Andrews S, Oxley D, Berrens RV, Branco MR, Reik W

Whole-genome bisulfite sequencing (WGBS) is becoming an increasingly accessible technique, used widely for both fundamental and disease-oriented research. Library preparation methods benefit from a variety of available kits, polymerases and bisulfite conversion protocols. Although some steps in the procedure, such as PCR amplification, are known to introduce biases, a systematic evaluation of biases in WGBS strategies is missing.

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Genome biology, 19, 1474-760X, 33, 2018

PMID: 29544553


Open Access

Bach2 Promotes B Cell Receptor-Induced Proliferation of B Lymphocytes and Represses Cyclin-Dependent Kinase Inhibitors.
Miura Y, Morooka M, Sax N, Roychoudhuri R, Itoh-Nakadai A, Brydun A, Funayama R, Nakayama K, Satomi S, Matsumoto M, Igarashi K, Muto A

BTB and CNC homology 2 (Bach2) is a transcriptional repressor that is required for the formation of the germinal center (GC) and reactions, including class switch recombination and somatic hypermutation of Ig genes in B cells, within the GC. Although BCR-induced proliferation is essential for GC reactions, the function of Bach2 in regulating B cell proliferation has not been elucidated. In this study, we demonstrate that Bach2 is required to sustain high levels of B cell proliferation in response to BCR signaling. Following BCR engagement in vitro, B cells from-deficient () mice showed lower incorporation of BrdU and reduced cell cycle progression compared with wild-type cells.B cells also underwent increased apoptosis, as evidenced by an elevated frequency of sub-Gcells and early apoptotic cells. Transcriptome analysis of BCR-engaged B cells frommice revealed reduced expression of the antiapoptotic geneencoding Bcl-xand elevated expression of cyclin-dependent kinase inhibitor (CKI) family genes, including,, andReconstitution of Bcl-xexpression partially rescued the proliferation defect ofB cells. Chromatin immunoprecipitation experiments showed that Bach2 bound to the CKI family genes, indicating that these genes are direct repression targets of Bach2. These findings identify Bach2 as a requisite factor for sustaining high levels of BCR-induced proliferation, survival, and cell cycle progression, and it promotes expression of Bcl-xand repression of CKI genes. BCR-induced proliferation defects may contribute to the impaired GC formation observed inmice.

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Journal of immunology (Baltimore, Md. : 1950), , 1550-6606, , 2018

PMID: 29540581


A niche of trophoblast progenitor cells identified by integrin α2 is present in first trimester human placentas.
Lee CQE, Turco M, Gardner L, Simons B, Hemberger M, Moffett A

During pregnancy the trophoblast cells of the placenta are the only fetal cells in direct contact with maternal blood and decidua. Their functions include transport of nutrients and oxygen, secretion of pregnancy hormones, remodelling the uterine arteries, and communicating with maternal cells. Despite the importance of trophoblast cells in placental development and successful pregnancy, little is known about the identity, location and differentiation of human trophoblast progenitors. We identify a proliferative trophoblast niche at the base of the cytotrophoblast cell columns in first trimester placentas that is characterised by integrin α2 (ITGA2) expression. Pulse-chase experiments with 5-Iodo-2'-deoxyuridine (IdU) imply that these cells can contribute to both villous (VCT) and extravillous (EVT) lineages. These proliferating trophoblast cells can be isolated using ITGA2 as a marker by flow cytometry and express genes from both VCT and EVT. Microarray expression analysis shows that ITAG2cells display a unique transcriptional signature including NOTCH signalling and a combination of epithelial and mesenchymal characteristics. ITGA2 thus marks a niche allowing the study of pure populations of trophoblast progenitor cells.

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Development (Cambridge, England), , 1477-9129, , 2018

PMID: 29540503


Placentation defects are highly prevalent in embryonic lethal mouse mutants.
Perez-Garcia V, Fineberg E, Wilson R, Murray A, Mazzeo CI, Tudor C, Sienerth A, White JK, Tuck E, Ryder EJ, Gleeson D, Siragher E, Wardle-Jones H, Staudt N, Wali N, Collins J, Geyer S, Busch-Nentwich EM, Galli A, Smith JC, Robertson E, Adams DJ, Weninger WJ, Mohun T, Hemberger M

Large-scale phenotyping efforts have demonstrated that approximately 25-30% of mouse gene knockouts cause intrauterine lethality. Analysis of these mutants has largely focused on the embryo and not the placenta, despite the crucial role of this extraembryonic organ for developmental progression. Here we screened 103 embryonic lethal and sub-viable mouse knockout lines from the Deciphering the Mechanisms of Developmental Disorders program for placental phenotypes. We found that 68% of knockout lines that are lethal at or after mid-gestation exhibited placental dysmorphologies. Early lethality (embryonic days 9.5-14.5) is almost always associated with severe placental malformations. Placental defects correlate strongly with abnormal brain, heart and vascular development. Analysis of mutant trophoblast stem cells and conditional knockouts suggests that a considerable number of factors that cause embryonic lethality when ablated have primary gene function in trophoblast cells. Our data highlight the hugely under-appreciated importance of placental defects in contributing to abnormal embryo development and suggest key molecular nodes that govern placenta formation.

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Nature, , 1476-4687, , 2018

PMID: 29539633


Long-Range Enhancer Interactions Are Prevalent in Mouse Embryonic Stem Cells and Are Reorganized upon Pluripotent State Transition.
Novo CL, Javierre BM, Cairns J, Segonds-Pichon A, Wingett SW, Freire-Pritchett P, Furlan-Magaril M, Schoenfelder S, Fraser P, Rugg-Gunn PJ

Transcriptional enhancers, including super-enhancers (SEs), form physical interactions with promoters to regulate cell-type-specific gene expression. SEs are characterized by high transcription factor occupancy and large domains of active chromatin, and they are commonly assigned to target promoters using computational predictions. How promoter-SE interactions change upon cell state transitions, and whether transcription factors maintain SE interactions, have not been reported. Here, we used promoter-capture Hi-C to identify promoters that interact with SEs in mouse embryonic stem cells (ESCs). We found that SEs form complex, spatial networks in which individual SEs contact multiple promoters, and a rewiring of promoter-SE interactions occurs between pluripotent states. We also show that long-range promoter-SE interactions are more prevalent in ESCs than in epiblast stem cells (EpiSCs) or Nanog-deficient ESCs. We conclude that SEs form cell-type-specific interaction networks that are partly dependent on core transcription factors, thereby providing insights into the gene regulatory organization of pluripotent cells.

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Cell reports, 22, 2211-1247, 2615-2627, 2018

PMID: 29514091


Open Access

Molecular profiling of aged neural progenitors identifies Dbx2 as a candidate regulator of age-associated neurogenic decline.
Lupo G, Nisi PS, Esteve P, Paul YL, Novo CL, Sidders B, Khan MA, Biagioni S, Liu HK, Bovolenta P, Cacci E, Rugg-Gunn PJ

Adult neurogenesis declines with aging due to the depletion and functional impairment of neural stem/progenitor cells (NSPCs). An improved understanding of the underlying mechanisms that drive age-associated neurogenic deficiency could lead to the development of strategies to alleviate cognitive impairment and facilitate neuroregeneration. An essential step towards this aim is to investigate the molecular changes that occur in NSPC aging on a genomewide scale. In this study, we compare the transcriptional, histone methylation and DNA methylation signatures of NSPCs derived from the subventricular zone (SVZ) of young adult (3 months old) and aged (18 months old) mice. Surprisingly, the transcriptional and epigenomic profiles of SVZ-derived NSPCs are largely unchanged in aged cells. Despite the global similarities, we detect robust age-dependent changes at several hundred genes and regulatory elements, thereby identifying putative regulators of neurogenic decline. Within this list, the homeobox gene Dbx2 is upregulated in vitro and in vivo, and its promoter region has altered histone and DNA methylation levels, in aged NSPCs. Using functional in vitro assays, we show that elevated Dbx2 expression in young adult NSPCs promotes age-related phenotypes, including the reduced proliferation of NSPC cultures and the altered transcript levels of age-associated regulators of NSPC proliferation and differentiation. Depleting Dbx2 in aged NSPCs caused the reverse gene expression changes. Taken together, these results provide new insights into the molecular programmes that are affected during mouse NSPC aging, and uncover a new functional role for Dbx2 in promoting age-related neurogenic decline.

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Aging cell, , 1474-9726, , 2018

PMID: 29504228


Open Access

Gene expression hallmarks of cellular ageing.
Frenk S, Houseley J

Ageing leads to dramatic changes in the physiology of many different tissues resulting in a spectrum of pathology. Nonetheless, many lines of evidence suggest that ageing is driven by highly conserved cell intrinsic processes, and a set of unifying hallmarks of ageing has been defined. Here, we survey reports of age-linked changes in basal gene expression across eukaryotes from yeast to human and identify six gene expression hallmarks of cellular ageing: downregulation of genes encoding mitochondrial proteins; downregulation of the protein synthesis machinery; dysregulation of immune system genes; reduced growth factor signalling; constitutive responses to stress and DNA damage; dysregulation of gene expression and mRNA processing. These encompass widely reported features of ageing such as increased senescence and inflammation, reduced electron transport chain activity and reduced ribosome synthesis, but also reveal a surprising lack of gene expression responses to known age-linked cellular stresses. We discuss how the existence of conserved transcriptomic hallmarks relates to genome-wide epigenetic differences underlying ageing clocks, and how the changing transcriptome results in proteomic alterations where data is available and to variations in cell physiology characteristic of ageing. Identification of gene expression events that occur during ageing across distant organisms should be informative as to conserved underlying mechanisms of ageing, and provide additional biomarkers to assess the effects of diet and other environmental factors on the rate of ageing.

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Biogerontology, , 1573-6768, , 2018

PMID: 29492790


Neuronal Cell Death.
Fricker M, Tolkovsky AM, Borutaite V, Coleman M, Brown GC

Neuronal cell death occurs extensively during development and pathology, where it is especially important because of the limited capacity of adult neurons to proliferate or be replaced. The concept of cell death used to be simple as there were just two or three types, so we just had to work out which type was involved in our particular pathology and then block it. However, we now know that there are at least a dozen ways for neurons to die, that blocking a particular mechanism of cell death may not prevent the cell from dying, and that non-neuronal cells also contribute to neuronal death. We review here the mechanisms of neuronal death by intrinsic and extrinsic apoptosis, oncosis, necroptosis, parthanatos, ferroptosis, sarmoptosis, autophagic cell death, autosis, autolysis, paraptosis, pyroptosis, phagoptosis, and mitochondrial permeability transition. We next explore the mechanisms of neuronal death during development, and those induced by axotomy, aberrant cell-cycle reentry, glutamate (excitoxicity and oxytosis), loss of connected neurons, aggregated proteins and the unfolded protein response, oxidants, inflammation, and microglia. We then reassess which forms of cell death occur in stroke and Alzheimer's disease, two of the most important pathologies involving neuronal cell death. We also discuss why it has been so difficult to pinpoint the type of neuronal death involved, if and why the mechanism of neuronal death matters, the molecular overlap and interplay between death subroutines, and the therapeutic implications of these multiple overlapping forms of neuronal death.

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Physiological reviews, 98, 1522-1210, 813-880, 2018

PMID: 29488822


scNMT-seq enables joint profiling of chromatin accessibility DNA methylation and transcription in single cells.
Clark SJ, Argelaguet R, Kapourani CA, Stubbs TM, Lee HJ, Alda-Catalinas C, Krueger F, Sanguinetti G, Kelsey G, Marioni JC, Stegle O, Reik W

Parallel single-cell sequencing protocols represent powerful methods for investigating regulatory relationships, including epigenome-transcriptome interactions. Here, we report a single-cell method for parallel chromatin accessibility, DNA methylation and transcriptome profiling. scNMT-seq (single-cell nucleosome, methylation and transcription sequencing) uses a GpC methyltransferase to label open chromatin followed by bisulfite and RNA sequencing. We validate scNMT-seq by applying it to differentiating mouse embryonic stem cells, finding links between all three molecular layers and revealing dynamic coupling between epigenomic layers during differentiation.

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Nature communications, 9, 2041-1723, 781, 2018

PMID: 29472610


ERK1/2 inhibitors: New weapons to inhibit the RAS-regulated RAF-MEK1/2-ERK1/2 pathway.
Kidger AM, Sipthorp J, Cook SJ

The RAS-regulated RAF-MEK1/2-ERK1/2 signalling pathway is de-regulated in a variety of cancers due to mutations in receptor tyrosine kinases (RTKs), negative regulators of RAS (such as NF1) and core pathway components themselves (RAS, BRAF, CRAF, MEK1 or MEK2). This has driven the development of a variety of pharmaceutical agents to inhibit RAF-MEK1/2-ERK1/2 signalling in cancer and both RAF and MEK inhibitors are now approved and used in the clinic. There is now much interest in targeting at the level of ERK1/2 for a variety of reasons. First, since the pathway is linear from RAF-to-MEK-to-ERK then ERK1/2 are validated as targets per se. Second, innate resistance to RAF or MEK inhibitors involves relief of negative feedback and pathway re-activation with all signalling going through ERK1/2, validating the use of ERK inhibitors with RAF or MEK inhibitors as an up-front combination. Third, long-term acquired resistance to RAF or MEK inhibitors involves a variety of mechanisms (KRAS or BRAF amplification, MEK mutation, etc.) which re-instate ERK activity, validating the use of ERK inhibitors to forestall acquired resistance to RAF or MEK inhibitors. The first potent highly selective ERK1/2 inhibitors have now been developed and are entering clinical trials. They have one of three discrete mechanisms of action - catalytic, "dual mechanism" or covalent - which could have profound consequences for how cells respond and adapt. In this review we describe the validation of ERK1/2 as anti-cancer drug targets, consider the mechanism of action of new ERK1/2 inhibitors and how this may impact on their efficacy, anticipate factors that will determine how tumour cells respond and adapt to ERK1/2 inhibitors and consider ERK1/2 inhibitor drug combinations.

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Pharmacology & therapeutics, , 1879-016X, , 2018

PMID: 29454854


Quick tips for creating effective and impactful biological pathways using the Systems Biology Graphical Notation.
Touré V, Le Novère N, Waltemath D, Wolkenhauer O

PLoS computational biology, 14, 1553-7358, e1005740, 2018

PMID: 29447151


Open Access

Thrombopoietin signaling to chromatin elicits rapid and pervasive epigenome remodeling within poised chromatin architectures.
Comoglio F, Park HJ, Schoenfelder S, Barozzi I, Bode D, Fraser P, Green AR

Thrombopoietin (TPO) is a critical cytokine regulating hematopoietic stem cell maintenance and differentiation into the megakaryocytic lineage. However, the transcriptional and chromatin dynamics elicited by TPO signaling are poorly understood. Here, we study the immediate early transcriptional and cis-regulatory responses to TPO in hematopoietic stem/progenitor cells (HSPCs) and use this paradigm of cytokine signaling to chromatin to dissect the relation between cis- regulatory activity and chromatin architecture. We show that TPO profoundly alters the transcriptome of HSPCs, with key hematopoietic regulators being transcriptionally repressed within 30 minutes of TPO. By examining cis-regulatory dynamics and chromatin architectures, we demonstrate that these changes are accompanied by rapid and extensive epigenome remodeling of cis-regulatory landscapes that is spatially coordinated within topologically associating domains (TADs). Moreover, TPO-responsive enhancers are spatially clustered and engage in preferential homotypic intra- and inter-TAD interactions that are largely refractory to TPO signaling. By further examining the link between cis-regulatory dynamics and chromatin looping, we show that rapid modulation of cis-regulatory activity is largely independent of chromatin looping dynamics. Finally, we show that, although activated and repressed cis-regulatory elements share remarkably similar DNA sequence compositions, transcription factor binding patterns accurately predict rapid cis-regulatory responses to TPO.

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Genome research, , 1549-5469, , 2018

PMID: 29429976


Open Access

Epigenetic control of CD8+ T cell differentiation.
Henning AN, Roychoudhuri R, Restifo NP

Upon stimulation, small numbers of naive CD8+ T cells proliferate and differentiate into a variety of memory and effector cell types. CD8+ T cells can persist for years and kill tumour cells and virally infected cells. The functional and phenotypic changes that occur during CD8+ T cell differentiation are well characterized, but the epigenetic states that underlie these changes are incompletely understood. Here, we review the epigenetic processes that direct CD8+ T cell differentiation and function. We focus on epigenetic modification of DNA and associated histones at genes and their regulatory elements. We also describe structural changes in chromatin organization that affect gene expression. Finally, we examine the translational potential of epigenetic interventions to improve CD8+ T cell function in individuals with chronic infections and cancer.

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Nature reviews. Immunology, , 1474-1741, , 2018

PMID: 29379213


The RNA-binding protein PTBP1 is necessary for B cell selection in germinal centers.
Monzón-Casanova E, Screen M, Díaz-Muñoz MD, Coulson RMR, Bell SE, Lamers G, Solimena M, Smith CWJ, Turner M

Antibody affinity maturation occurs in germinal centers (GCs), where B cells cycle between the light zone (LZ) and the dark zone. In the LZ, GC B cells bearing immunoglobulins with the highest affinity for antigen receive positive selection signals from helper T cells, which promotes their rapid proliferation. Here we found that the RNA-binding protein PTBP1 was needed for the progression of GC B cells through late S phase of the cell cycle and for affinity maturation. PTBP1 was required for proper expression of the c-MYC-dependent gene program induced in GC B cells receiving T cell help and directly regulated the alternative splicing and abundance of transcripts that are increased during positive selection to promote proliferation.

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Nature immunology, , 1529-2916, , 2018

PMID: 29358707


PI3K induces B-cell development and regulates B cell identity.
Abdelrasoul H, Werner M, Setz CS, Okkenhaug K, Jumaa H

Phosphoinositide-3 kinase (PI3K) signaling is important for the survival of numerous cell types and class IA of PI3K is specifically required for the development of B cells but not for T cell development. Here, we show that class IA PI3K-mediated signals induce the expression of the transcription factor Pax5, which plays a central role in B cell commitment and differentiation by activating the expression of central B cell-specific signaling proteins such as SLP-65 and CD19. Defective class IA PI3K function leads to reduction in Pax5 expression and prevents B cell development beyond the stage expressing the precursor B cell receptor (pre-BCR). Investigating the mechanism of PI3K-induced Pax5 expression revealed that it involves a network of transcription factors including FoxO1 and Irf4 that directly binds to the Pax5 gene. Together, our results suggest that PI3K signaling links survival and differentiation of developing B cells with B cell identity and that decreased PI3K activity in pre-B cells results in reduced Pax5 expression and lineage plasticity.

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Scientific reports, 8, 2045-2322, 1327, 2018

PMID: 29358580


Open Access

RNA-binding proteins control gene expression and cell fate in the immune system.
Turner M, Díaz-Muñoz MD

RNA-binding proteins (RBPs) are essential for the development and function of the immune system. They interact dynamically with RNA to control its biogenesis and turnover by transcription-dependent and transcription-independent mechanisms. In this Review, we discuss the molecular mechanisms by which RBPs allow gene expression changes to occur at different speeds and to varying degrees, and which RBPs regulate the diversity of the transcriptome and proteome. These proteins are nodes for integration of transcriptional and signaling networks and are intimately linked to intermediary metabolism. They are essential components of regulatory feedback mechanisms that maintain immune tolerance and limit inflammation. The role of RBPs in malignancy and autoimmunity has led to their emergence as targets for the development of new therapeutic modalities.

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Nature immunology, , 1529-2916, , 2018

PMID: 29348497


MLL2 conveys transcription-independent H3K4 trimethylation in oocytes.
Hanna CW, Taudt A, Huang J, Gahurova L, Kranz A, Andrews S, Dean W, Stewart AF, Colomé-Tatché M, Kelsey G

Histone 3 K4 trimethylation (depositing H3K4me3 marks) is typically associated with active promoters yet paradoxically occurs at untranscribed domains. Research to delineate the mechanisms of targeting H3K4 methyltransferases is ongoing. The oocyte provides an attractive system to investigate these mechanisms, because extensive H3K4me3 acquisition occurs in nondividing cells. We developed low-input chromatin immunoprecipitation to interrogate H3K4me3, H3K27ac and H3K27me3 marks throughout oogenesis. In nongrowing oocytes, H3K4me3 was restricted to active promoters, but as oogenesis progressed, H3K4me3 accumulated in a transcription-independent manner and was targeted to intergenic regions, putative enhancers and silent H3K27me3-marked promoters. Ablation of the H3K4 methyltransferase gene Mll2 resulted in loss of transcription-independent H3K4 trimethylation but had limited effects on transcription-coupled H3K4 trimethylation or gene expression. Deletion of Dnmt3a and Dnmt3b showed that DNA methylation protects regions from acquiring H3K4me3. Our findings reveal two independent mechanisms of targeting H3K4me3 to genomic elements, with MLL2 recruited to unmethylated CpG-rich regions independently of transcription.

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Nature structural & molecular biology, 25, 1545-9985, 73-82, 2018

PMID: 29323282


Microbiota derived short chain fatty acids promote histone crotonylation in the colon through histone deacetylases.
Fellows R, Denizot J, Stellato C, Cuomo A, Jain P, Stoyanova E, Balázsi S, Hajnády Z, Liebert A, Kazakevych J, Blackburn H, Corrêa RO, Fachi JL, Sato FT, Ribeiro WR, Ferreira CM, Perée H, Spagnuolo M, Mattiuz R, Matolcsi C, Guedes J, Clark J, Veldhoen M, Bonaldi T, Vinolo MAR, Varga-Weisz P

The recently discovered histone post-translational modification crotonylation connects cellular metabolism to gene regulation. Its regulation and tissue-specific functions are poorly understood. We characterize histone crotonylation in intestinal epithelia and find that histone H3 crotonylation at lysine 18 is a surprisingly abundant modification in the small intestine crypt and colon, and is linked to gene regulation. We show that this modification is highly dynamic and regulated during the cell cycle. We identify class I histone deacetylases, HDAC1, HDAC2, and HDAC3, as major executors of histone decrotonylation. We show that known HDAC inhibitors, including the gut microbiota-derived butyrate, affect histone decrotonylation. Consistent with this, we find that depletion of the gut microbiota leads to a global change in histone crotonylation in the colon. Our results suggest that histone crotonylation connects chromatin to the gut microbiota, at least in part, via short-chain fatty acids and HDACs.

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Nature communications, 9, 2041-1723, 105, 2018

PMID: 29317660


Open Access