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Weihong Ge

Bio: Weihong Ge is an academic researcher from University of California, Los Angeles. The author has contributed to research in topics: Cellular differentiation & Spinal cord injury. The author has an hindex of 14, co-authored 17 publications receiving 3837 citations.

Papers
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Journal ArticleDOI
23 Jul 2010-Science
TL;DR: Genome-wide analysis of postnatal NSCs indicates that Dnmt3a occupies and methylates intergenic regions and gene bodies flanking proximal promoters of a large cohort of transcriptionally permissive genes, many of which encode regulators of neurogenesis and may be used for maintaining active chromatin states of genes critical for development.
Abstract: DNA methylation at proximal promoters facilitates lineage restriction by silencing cell type-specific genes. However, euchromatic DNA methylation frequently occurs in regions outside promoters. The functions of such nonproximal promoter DNA methylation are unclear. Here we show that the de novo DNA methyltransferase Dnmt3a is expressed in postnatal neural stem cells (NSCs) and is required for neurogenesis. Genome-wide analysis of postnatal NSCs indicates that Dnmt3a occupies and methylates intergenic regions and gene bodies flanking proximal promoters of a large cohort of transcriptionally permissive genes, many of which encode regulators of neurogenesis. Surprisingly, Dnmt3a-dependent nonproximal promoter methylation promotes expression of these neurogenic genes by functionally antagonizing Polycomb repression. Thus, nonpromoter DNA methylation by Dnmt3a may be used for maintaining active chromatin states of genes critical for development.

577 citations

Journal ArticleDOI
TL;DR: This study suggests that during the neurogenic period, DNA methylation inhibits not only astroglial marker genes but also genes that are essential for JAK-STAT signaling, and demethylation of these two groups of genes and subsequent elevation of STAT activity are key mechanisms that control the timing and magnitude of astrocyte differentiation.
Abstract: DNA methylation is a major epigenetic factor that has been postulated to regulate cell lineage differentiation. We report here that conditional gene deletion of the maintenance DNA methyltransferase I (Dnmt1) in neural progenitor cells (NPCs) results in DNA hypomethylation and precocious astroglial differentiation. The developmentally regulated demethylation of astrocyte marker genes as well as genes encoding the crucial components of the gliogenic JAK-STAT pathway is accelerated in Dnmt1 –/– NPCs. Through a chromatin remodeling process, demethylation of genes in the JAK-STAT pathway leads to an enhanced activation of STATs, which in turn triggers astrocyte differentiation. Our study suggests that during the neurogenic period, DNA methylation inhibits not only astroglial marker genes but also genes that are essential for JAK-STAT signaling. Thus, demethylation of these two groups of genes and subsequent elevation of STAT activity are key mechanisms that control the timing and magnitude of astroglial differentiation.

405 citations

Journal ArticleDOI
TL;DR: It is reported that the overall activity of Jak-STAT signaling is dynamically regulated in mouse cortical germinal zone during development, and observations suggest that autoregulation of the Jak- STAT pathway controls the onset of astrogliogenesis.
Abstract: During development of the CNS, neurons and glia are generated in a sequential manner. The mechanism underlying the later onset of gliogenesis is poorly understood, although the cytokine-induced Jak-STAT pathway has been postulated to regulate astrogliogenesis. Here, we report that the overall activity of Jak-STAT signaling is dynamically regulated in mouse cortical germinal zone during development. As such, activated STAT1/3 and STAT-mediated transcription are negligible at early, neurogenic stages, when neurogenic factors are highly expressed. At later, gliogenic periods, decreased expression of neurogenic factors causes robust elevation of STAT activity. Our data demonstrate a positive autoregulatory loop whereby STAT1/3 directly induces the expression of various components of the Jak-STAT pathway to strengthen STAT signaling and trigger astrogliogenesis. Forced activation of Jak-STAT signaling leads to precocious astrogliogenesis, and inhibition of this pathway blocks astrocyte differentiation. These observations suggest that autoregulation of the Jak-STAT pathway controls the onset of astrogliogenesis.

371 citations

Journal ArticleDOI
TL;DR: Dll3 functions not as an activator as previously reported but rather as a dedicated inhibitor of N signaling, and together with the modulator lunatic fringe, Dll3 altered N signaling levels that were induced by other DSL ligands.
Abstract: Mutations in the DSL (Delta, Serrate, Lag2) Notch (N) ligand Delta-like (Dll) 3 cause skeletal abnormalities in spondylocostal dysostosis, which is consistent with a critical role for N signaling during somitogenesis. Understanding how Dll3 functions is complicated by reports that DSL ligands both activate and inhibit N signaling. In contrast to other DSL ligands, we show that Dll3 does not activate N signaling in multiple assays. Consistent with these findings, Dll3 does not bind to cells expressing any of the four N receptors, and N1 does not bind Dll3-expressing cells. However, in a cell-autonomous manner, Dll3 suppressed N signaling, as was found for other DSL ligands. Therefore, Dll3 functions not as an activator as previously reported but rather as a dedicated inhibitor of N signaling. As an N antagonist, Dll3 promoted Xenopus laevis neurogenesis and inhibited glial differentiation of mouse neural progenitors. Finally, together with the modulator lunatic fringe, Dll3 altered N signaling levels that were induced by other DSL ligands.

286 citations


Cited by
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Journal ArticleDOI
06 Sep 2012-Nature
TL;DR: The Encyclopedia of DNA Elements project provides new insights into the organization and regulation of the authors' genes and genome, and is an expansive resource of functional annotations for biomedical research.
Abstract: The human genome encodes the blueprint of life, but the function of the vast majority of its nearly three billion bases is unknown. The Encyclopedia of DNA Elements (ENCODE) project has systematically mapped regions of transcription, transcription factor association, chromatin structure and histone modification. These data enabled us to assign biochemical functions for 80% of the genome, in particular outside of the well-studied protein-coding regions. Many discovered candidate regulatory elements are physically associated with one another and with expressed genes, providing new insights into the mechanisms of gene regulation. The newly identified elements also show a statistical correspondence to sequence variants linked to human disease, and can thereby guide interpretation of this variation. Overall, the project provides new insights into the organization and regulation of our genes and genome, and is an expansive resource of functional annotations for biomedical research.

13,548 citations

Journal Article
01 Jan 2012-Nature
TL;DR: The Encyclopedia of DNA Elements project provides new insights into the organization and regulation of the authors' genes and genome, and is an expansive resource of functional annotations for biomedical research.
Abstract: The human genome encodes the blueprint of life, but the function of the vast majority of its nearly three billion bases is unknown. The Encyclopedia of DNA Elements (ENCODE) project has systematically mapped regions of transcription, transcription factor association, chromatin structure and histone modification. These data enabled us to assign biochemical functions for 80% of the genome, in particular outside of the well-studied protein-coding regions. Many discovered candidate regulatory elements are physically associated with one another and with expressed genes, providing new insights into the mechanisms of gene regulation. The newly identified elements also show a statistical correspondence to sequence variants linked to human disease, and can thereby guide interpretation of this variation. Overall, the project provides new insights into the organization and regulation of our genes and genome, and is an expansive resource of functional annotations for biomedical research.

8,106 citations

Journal ArticleDOI
18 Dec 2014-Cell
TL;DR: In situ Hi-C is used to probe the 3D architecture of genomes, constructing haploid and diploid maps of nine cell types, identifying ∼10,000 loops that frequently link promoters and enhancers, correlate with gene activation, and show conservation across cell types and species.

5,945 citations

Journal ArticleDOI
TL;DR: Dysregulation of these ncRNAs is being found to have relevance not only to tumorigenesis, but also to neurological, cardiovascular, developmental and other diseases, and there is great interest in therapeutic strategies to counteract these perturbations.
Abstract: The role of non-coding RNAs (ncRNAs) in disease is best understood for microRNAs in cancer. However, there is increasing interest in the disease-related roles of other ncRNAs — including piRNAs, snoRNAs, T-UCRs and lncRNAs — and in using this knowledge for therapy.

4,016 citations

Journal ArticleDOI
Timothy J. Ley1, Christopher A. Miller1, Li Ding1, Benjamin J. Raphael2, Andrew J. Mungall3, Gordon Robertson3, Katherine A. Hoadley4, Timothy J. Triche5, Peter W. Laird5, Jack Baty1, Lucinda Fulton1, Robert S. Fulton1, Sharon Heath1, Joelle Kalicki-Veizer1, Cyriac Kandoth1, Jeffery M. Klco1, Daniel C. Koboldt1, Krishna L. Kanchi1, Shashikant Kulkarni1, Tamara Lamprecht1, David E. Larson1, G. Lin1, Charles Lu1, Michael D. McLellan1, Joshua F. McMichael1, Jacqueline E. Payton1, Heather Schmidt1, David H. Spencer1, Michael H. Tomasson1, John W. Wallis1, Lukas D. Wartman1, Mark A. Watson1, John S. Welch1, Michael C. Wendl1, Adrian Ally3, Miruna Balasundaram3, Inanc Birol3, Yaron S.N. Butterfield3, Readman Chiu3, Andy Chu3, Eric Chuah3, Hye Jung E. Chun3, Richard Corbett3, Noreen Dhalla3, Ranabir Guin3, An He3, Carrie Hirst3, Martin Hirst3, Robert A. Holt3, Steven J.M. Jones3, Aly Karsan3, Darlene Lee3, Haiyan I. Li3, Marco A. Marra3, Michael Mayo3, Richard A. Moore3, Karen Mungall3, Jeremy Parker3, Erin Pleasance3, Patrick Plettner3, Jacquie Schein3, Dominik Stoll3, Lucas Swanson3, Angela Tam3, Nina Thiessen3, Richard Varhol3, Natasja Wye3, Yongjun Zhao3, Stacey Gabriel6, Gad Getz6, Carrie Sougnez6, Lihua Zou6, Mark D.M. Leiserson2, Fabio Vandin2, Hsin-Ta Wu2, Frederick Applebaum7, Stephen B. Baylin8, Rehan Akbani9, Bradley M. Broom9, Ken Chen9, Thomas C. Motter9, Khanh Thi-Thuy Nguyen9, John N. Weinstein9, Nianziang Zhang9, Martin L. Ferguson, Christopher Adams10, Aaron D. Black10, Jay Bowen10, Julie M. Gastier-Foster10, Thomas Grossman10, Tara M. Lichtenberg10, Lisa Wise10, Tanja Davidsen11, John A. Demchok11, Kenna R. Mills Shaw11, Margi Sheth11, Heidi J. Sofia, Liming Yang11, James R. Downing, Greg Eley, Shelley Alonso12, Brenda Ayala12, Julien Baboud12, Mark Backus12, Sean P. Barletta12, Dominique L. Berton12, Anna L. Chu12, Stanley Girshik12, Mark A. Jensen12, Ari B. Kahn12, Prachi Kothiyal12, Matthew C. Nicholls12, Todd Pihl12, David Pot12, Rohini Raman12, Rashmi N. Sanbhadti12, Eric E. Snyder12, Deepak Srinivasan12, Jessica Walton12, Yunhu Wan12, Zhining Wang12, Jean Pierre J. Issa13, Michelle M. Le Beau14, Martin Carroll15, Hagop M. Kantarjian, Steven M. Kornblau, Moiz S. Bootwalla5, Phillip H. Lai5, Hui Shen5, David Van Den Berg5, Daniel J. Weisenberger5, Daniel C. Link1, Matthew J. Walter1, Bradley A. Ozenberger11, Elaine R. Mardis1, Peter Westervelt1, Timothy A. Graubert1, John F. DiPersio1, Richard K. Wilson1 
TL;DR: It is found that a complex interplay of genetic events contributes to AML pathogenesis in individual patients and the databases from this study are widely available to serve as a foundation for further investigations of AMl pathogenesis, classification, and risk stratification.
Abstract: BACKGROUND—Many mutations that contribute to the pathogenesis of acute myeloid leukemia (AML) are undefined The relationships between patterns of mutations and epigenetic phenotypes are not yet clear METHODS—We analyzed the genomes of 200 clinically annotated adult cases of de novo AML, using either whole-genome sequencing (50 cases) or whole-exome sequencing (150 cases), along with RNA and microRNA sequencing and DNA-methylation analysis RESULTS—AML genomes have fewer mutations than most other adult cancers, with an average of only 13 mutations found in genes Of these, an average of 5 are in genes that are recurrently mutated in AML A total of 23 genes were significantly mutated, and another 237 were mutated in two or more samples Nearly all samples had at least 1 nonsynonymous mutation in one of nine categories of genes that are almost certainly relevant for pathogenesis, including transcriptionfactor fusions (18% of cases), the gene encoding nucleophosmin (NPM1) (27%), tumorsuppressor genes (16%), DNA-methylation–related genes (44%), signaling genes (59%), chromatin-modifying genes (30%), myeloid transcription-factor genes (22%), cohesin-complex genes (13%), and spliceosome-complex genes (14%) Patterns of cooperation and mutual exclusivity suggested strong biologic relationships among several of the genes and categories CONCLUSIONS—We identified at least one potential driver mutation in nearly all AML samples and found that a complex interplay of genetic events contributes to AML pathogenesis in individual patients The databases from this study are widely available to serve as a foundation for further investigations of AML pathogenesis, classification, and risk stratification (Funded by the National Institutes of Health) The molecular pathogenesis of acute myeloid leukemia (AML) has been studied with the use of cytogenetic analysis for more than three decades Recurrent chromosomal structural variations are well established as diagnostic and prognostic markers, suggesting that acquired genetic abnormalities (ie, somatic mutations) have an essential role in pathogenesis 1,2 However, nearly 50% of AML samples have a normal karyotype, and many of these genomes lack structural abnormalities, even when assessed with high-density comparative genomic hybridization or single-nucleotide polymorphism (SNP) arrays 3-5 (see Glossary) Targeted sequencing has identified recurrent mutations in FLT3, NPM1, KIT, CEBPA, and TET2 6-8 Massively parallel sequencing enabled the discovery of recurrent mutations in DNMT3A 9,10 and IDH1 11 Recent studies have shown that many patients with

3,980 citations