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Engel JL, Zhang X, Lu DR, Vila OF, Arias V, Lee J, Hale C, Hsu YH, Li CM, Wu RS, Vedantham V, Ang YS. Single Cell Multi-Omics of an iPSC Model of Human Sinoatrial Node Development Reveals Genetic Determinants of Heart Rate and Arrhythmia Susceptibility. bioRxiv 2023:2023.07.01.547335. [PMID: 37425707 PMCID: PMC10327193 DOI: 10.1101/2023.07.01.547335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Cellular heterogeneity within the sinoatrial node (SAN) is functionally important but has been difficult to model in vitro , presenting a major obstacle to studies of heart rate regulation and arrhythmias. Here we describe a scalable method to derive sinoatrial node pacemaker cardiomyocytes (PCs) from human induced pluripotent stem cells that recapitulates differentiation into distinct PC subtypes, including SAN Head, SAN Tail, transitional zone cells, and sinus venosus myocardium. Single cell (sc) RNA-sequencing, sc-ATAC-sequencing, and trajectory analyses were used to define epigenetic and transcriptomic signatures of each cell type, and to identify novel transcriptional pathways important for PC subtype differentiation. Integration of our multi-omics datasets with genome wide association studies uncovered cell type-specific regulatory elements that associated with heart rate regulation and susceptibility to atrial fibrillation. Taken together, these datasets validate a novel, robust, and realistic in vitro platform that will enable deeper mechanistic exploration of human cardiac automaticity and arrhythmia.
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Zhu L, Choudhary K, Gonzalez-Teran B, Ang YS, Thomas R, Stone NR, Liu L, Zhou P, Zhu C, Ruan H, Huang Y, Jin S, Pelonero A, Koback F, Padmanabhan A, Sadagopan N, Hsu A, Costa MW, Gifford CA, van Bemmel J, Hüttenhain R, Vedantham V, Conklin BR, Black BL, Bruneau BG, Steinmetz L, Krogan NJ, Pollard KS, Srivastava D. Transcription Factor GATA4 Regulates Cell Type-Specific Splicing Through Direct Interaction With RNA in Human Induced Pluripotent Stem Cell-Derived Cardiac Progenitors. Circulation 2022; 146:770-787. [PMID: 35938400 PMCID: PMC9452483 DOI: 10.1161/circulationaha.121.057620] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
BACKGROUND GATA4 (GATA-binding protein 4), a zinc finger-containing, DNA-binding transcription factor, is essential for normal cardiac development and homeostasis in mice and humans, and mutations in this gene have been reported in human heart defects. Defects in alternative splicing are associated with many heart diseases, yet relatively little is known about how cell type- or cell state-specific alternative splicing is achieved in the heart. Here, we show that GATA4 regulates cell type-specific splicing through direct interaction with RNA and the spliceosome in human induced pluripotent stem cell-derived cardiac progenitors. METHODS We leveraged a combination of unbiased approaches including affinity purification of GATA4 and mass spectrometry, enhanced cross-linking with immunoprecipitation, electrophoretic mobility shift assays, in vitro splicing assays, and unbiased transcriptomic analysis to uncover GATA4's novel function as a splicing regulator in human induced pluripotent stem cell-derived cardiac progenitors. RESULTS We found that GATA4 interacts with many members of the spliceosome complex in human induced pluripotent stem cell-derived cardiac progenitors. Enhanced cross-linking with immunoprecipitation demonstrated that GATA4 also directly binds to a large number of mRNAs through defined RNA motifs in a sequence-specific manner. In vitro splicing assays indicated that GATA4 regulates alternative splicing through direct RNA binding, resulting in functionally distinct protein products. Correspondingly, knockdown of GATA4 in human induced pluripotent stem cell-derived cardiac progenitors resulted in differential alternative splicing of genes involved in cytoskeleton organization and calcium ion import, with functional consequences associated with the protein isoforms. CONCLUSIONS This study shows that in addition to its well described transcriptional function, GATA4 interacts with members of the spliceosome complex and regulates cell type-specific alternative splicing via sequence-specific interactions with RNA. Several genes that have splicing regulated by GATA4 have functional consequences and many are associated with dilated cardiomyopathy, suggesting a novel role for GATA4 in achieving the necessary cardiac proteome in normal and stress-responsive conditions.
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Affiliation(s)
- Lili Zhu
- Gladstone Institutes, San Francisco, CA, USA
- Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA, USA
| | | | - Barbara Gonzalez-Teran
- Gladstone Institutes, San Francisco, CA, USA
- Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA, USA
| | - Yen-Sin Ang
- Gladstone Institutes, San Francisco, CA, USA
- Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA, USA
| | | | - Nicole R. Stone
- Gladstone Institutes, San Francisco, CA, USA
- Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA, USA
| | - Lei Liu
- Gladstone Institutes, San Francisco, CA, USA
- Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA, USA
| | - Ping Zhou
- Gladstone Institutes, San Francisco, CA, USA
- Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA, USA
| | - Chenchen Zhu
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Genome Technology Center, Palo Alto, CA, USA
| | - Hongmei Ruan
- Department of Medicine, University of California, San Francisco, CA, USA
- Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| | - Yu Huang
- Gladstone Institutes, San Francisco, CA, USA
- Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA, USA
| | - Shibo Jin
- Division of Cellular and Developmental Biology, Molecular and Cell Biology Department, University of California at Berkeley, Berkeley, CA, USA
| | - Angelo Pelonero
- Gladstone Institutes, San Francisco, CA, USA
- Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA, USA
| | - Frances Koback
- Gladstone Institutes, San Francisco, CA, USA
- Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA, USA
| | - Arun Padmanabhan
- Gladstone Institutes, San Francisco, CA, USA
- Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA, USA
| | - Nandhini Sadagopan
- Gladstone Institutes, San Francisco, CA, USA
- Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA, USA
| | - Austin Hsu
- Gladstone Institutes, San Francisco, CA, USA
| | - Mauro W. Costa
- Gladstone Institutes, San Francisco, CA, USA
- Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA, USA
| | - Casey A. Gifford
- Gladstone Institutes, San Francisco, CA, USA
- Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA, USA
| | - Joke van Bemmel
- Gladstone Institutes, San Francisco, CA, USA
- Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA, USA
| | - Ruth Hüttenhain
- Gladstone Institutes, San Francisco, CA, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, CA, USA
| | - Vasanth Vedantham
- Department of Medicine, University of California, San Francisco, CA, USA
- Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| | - Bruce R. Conklin
- Gladstone Institutes, San Francisco, CA, USA
- Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA, USA
- Department of Medicine, University of California, San Francisco, CA, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA
| | - Brian L. Black
- Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| | - Benoit G. Bruneau
- Gladstone Institutes, San Francisco, CA, USA
- Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA, USA
- Cardiovascular Research Institute, University of California, San Francisco, CA, USA
- Department of Pediatrics, University of California, San Francisco, CA, USA
| | - Lars Steinmetz
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Genome Technology Center, Palo Alto, CA, USA
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany
| | - Nevan J. Krogan
- Gladstone Institutes, San Francisco, CA, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, CA, USA
| | - Katherine S. Pollard
- Gladstone Institutes, San Francisco, CA, USA
- Chan Zuckerberg Biohub, San Francisco, CA, USA
- Department of Epidemiology & Biostatistics, Institute for Computational Health Sciences, and Institute for Human Genetics, University of California, San Francisco, CA, USA
| | - Deepak Srivastava
- Gladstone Institutes, San Francisco, CA, USA
- Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA, USA
- Department of Pediatrics, University of California, San Francisco, CA, USA
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA, USA
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Su J, Zhu D, Huo Z, Gingold JA, Ang YS, Tu J, Zhou R, Lin Y, Luo H, Yang H, Zhao R, Schaniel C, Moore KA, Lemischka IR, Lee DF. Genomic Integrity Safeguards Self-Renewal in Embryonic Stem Cells. Cell Rep 2020; 28:1400-1409.e4. [PMID: 31390555 PMCID: PMC6708277 DOI: 10.1016/j.celrep.2019.07.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 04/25/2019] [Accepted: 07/02/2019] [Indexed: 01/06/2023] Open
Abstract
A multitude of signals are coordinated to maintain self-renewal in embryonic stem cells (ESCs). To unravel the essential internal and external signals required for sustaining the ESC state, we expand upon a set of ESC pluripotency-associated phosphoregulators (PRs) identified previously by short hairpin RNA (shRNA) screening. In addition to the previously described Aurka, we identify 4 additional PRs (Bub1b, Chek1, Ppm1g, and Ppp2r1b) whose depletion compromises self-renewal and leads to consequent differentiation. Global gene expression profiling and computational analyses reveal that knockdown of the 5 PRs leads to DNA damage/genome instability, activating p53 and culminating in ESC differentiation. Similarly, depletion of genome integrity-associated genes involved in DNA replication and checkpoint, mRNA processing, and Charcot-Marie-Tooth disease lead to compromise of ESC self-renewal via an increase in p53 activity. Our studies demonstrate an essential link between genomic integrity and developmental cell fate regulation in ESCs.
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Affiliation(s)
- Jie Su
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; The Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; The Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Cancer Biology and Genetics Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Dandan Zhu
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Zijun Huo
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA; Department of Endocrinology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China
| | - Julian A Gingold
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; The Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; The Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Women's Health Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
| | - Yen-Sin Ang
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; The Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; The Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Jian Tu
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA; Department of Musculoskeletal Oncology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China
| | - Ruoji Zhou
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA; The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX 77030, USA
| | - Yu Lin
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA; Institute of Clinical Pharmacology, Guangzhou University of Chinese Medicine, Guangzhou 510006, China
| | - Haidan Luo
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA; Department of Pathophysiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Huiling Yang
- Department of Pathophysiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Ruiying Zhao
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Christoph Schaniel
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; The Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; The Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Kateri A Moore
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; The Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; The Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Ihor R Lemischka
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; The Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; The Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Dung-Fang Lee
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; The Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA; The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX 77030, USA; Center for Stem Cell and Regenerative Medicine, The Brown Foundation Institute of Molecular Medicine for the Prevention of Human Diseases, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA; Center for Precision Health, School of Biomedical Informatics, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
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Ang YS, Yu J, Li N, Ndungu J, Rajamani S. Abstract 216: Establishing an Integrated Platform to Validate Genetic Targets Associated With Atrial Remodeling. Circ Res 2020. [DOI: 10.1161/res.127.suppl_1.216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Atrial fibrillation (AF)–the most common form of arrhythmia in the general population– is a grievous illness and a public health concern of global and epidemic scale. Current pharmacological therapies targeting ion channels or β-receptors are only partially effective and often fail to reduce AF burdens or mortality. We hypothesized that structural atrial remodeling, in addition to electrical remodeling, are key drivers of AF initiation and progression. In order to discover unrecognized drivers of AF mechanisms and reduce attrition rates in drug development, we employed Genome-Wide Association Studies (GWAS) to identify novel targets with human genetic validation. Meta-analyses of multi-ethnic patient cohorts reported 134 genetic loci, and therefore hundreds of coding variants, that are associated with AF. Atrial-specific cardiomyocytes (aCMs) differentiated from induced pluripotent stem cells (iPSCs) offer a human-relevant model system to study atrial remodeling. We combined aCMs with phenotyping platforms like Multi-Electrode Array (MEA) and Traction Force Microscopy (TFM), to evaluate whether unknown genes play a role in either cardiac conductance and/or contraction. We first devised a multi-factorial computational ranking algorithm based on WASPAS to select 50 out of 187 protein-coding targets. Next, we performed a focused loss-of-function phenotypic screen in aCMs to determine their requirement for atrial myocyte function. This resulted in the prioritization of six high value targets with diverse roles in Rho signaling, cell migration, ER stress response and integrin signaling. We also developed efficient CRISPR/Cas9 gene editing of GWAS variants as well as gain-of-function methods in aCMs. The completion of this project will establish an integrated platform for the functional validation of human genetic targets emerging from population studies associated with atrial remodeling.
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Affiliation(s)
| | - John Yu
- Amgen, South San Francisco, CA
| | - Ning Li
- Amgen, South San Francisco, CA
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5
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Abstract
Atrial fibrillation (AF) is a highly prevalent cardiac arrhythmia and cause of significant morbidity and mortality. Its increasing prevalence in aging societies constitutes a growing challenge to global healthcare systems. Despite substantial unmet needs in AF prevention and treatment, drug developments hitherto have been challenging, and the current pharmaceutical pipeline is nearly empty. In this review, we argue that current drugs for AF are inadequate because of an oversimplified system for patient classification and the development of drugs that do not interdict underlying disease mechanisms. We posit that an improved understanding of AF molecular pathophysiology related to the continuous identification of novel disease-modifying drug targets and an increased appreciation of patient heterogeneity provide a new framework to personalize AF drug development. Together with recent innovations in diagnostics, remote rhythm monitoring, and big data capabilities, we anticipate that adoption of a new framework for patient subsegmentation based on pathophysiological, genetic, and molecular subsets will improve success rates of clinical trials and advance drugs that reduce the individual patient and public health burden of AF.
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Affiliation(s)
- Yen-Sin Ang
- From Amgen Research, Cardiometabolic Disorders, South San Francisco, CA (Y.-S.A., S.R., S.M.H.)
| | - Sridharan Rajamani
- From Amgen Research, Cardiometabolic Disorders, South San Francisco, CA (Y.-S.A., S.R., S.M.H.)
| | - Saptarsi M. Haldar
- From Amgen Research, Cardiometabolic Disorders, South San Francisco, CA (Y.-S.A., S.R., S.M.H.)
- Gladstone Institutes, San Francisco, CA (S.M.H.)
- Department of Medicine, Cardiology Division, UCSF School of Medicine, San Francisco, CA (S.M.H.)
| | - Jörg Hüser
- Bayer AG, Pharma-RD-PCR TA Cardiovascular Disease, Wuppertal, Germany (J.H.)
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Mohamed TMA, Ang YS, Radzinsky E, Zhou P, Huang Y, Elfenbein A, Foley A, Magnitsky S, Srivastava D. Regulation of Cell Cycle to Stimulate Adult Cardiomyocyte Proliferation and Cardiac Regeneration. Cell 2018; 173:104-116.e12. [PMID: 29502971 DOI: 10.1016/j.cell.2018.02.014] [Citation(s) in RCA: 355] [Impact Index Per Article: 59.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 01/02/2018] [Accepted: 02/06/2018] [Indexed: 01/01/2023]
Abstract
Human diseases are often caused by loss of somatic cells that are incapable of re-entering the cell cycle for regenerative repair. Here, we report a combination of cell-cycle regulators that induce stable cytokinesis in adult post-mitotic cells. We screened cell-cycle regulators expressed in proliferating fetal cardiomyocytes and found that overexpression of cyclin-dependent kinase 1 (CDK1), CDK4, cyclin B1, and cyclin D1 efficiently induced cell division in post-mitotic mouse, rat, and human cardiomyocytes. Overexpression of the cell-cycle regulators was self-limiting through proteasome-mediated degradation of the protein products. In vivo lineage tracing revealed that 15%-20% of adult cardiomyocytes expressing the four factors underwent stable cell division, with significant improvement in cardiac function after acute or subacute myocardial infarction. Chemical inhibition of Tgf-β and Wee1 made CDK1 and cyclin B dispensable. These findings reveal a discrete combination of genes that can efficiently unlock the proliferative potential in cells that have terminally exited the cell cycle.
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Affiliation(s)
- Tamer M A Mohamed
- Gladstone Institute of Cardiovascular Disease and Roddenberry Stem Cell Center, San Francisco, CA 94158, USA; Institute of Cardiovascular Sciences, University of Manchester, Manchester M13 9PT, UK; Faculty of Pharmacy, Zagazig University, Al Sharqia Governorate, Egypt; Tenaya Therapeutics, South San Francisco, CA 94080, USA
| | - Yen-Sin Ang
- Gladstone Institute of Cardiovascular Disease and Roddenberry Stem Cell Center, San Francisco, CA 94158, USA
| | - Ethan Radzinsky
- Gladstone Institute of Cardiovascular Disease and Roddenberry Stem Cell Center, San Francisco, CA 94158, USA
| | - Ping Zhou
- Gladstone Institute of Cardiovascular Disease and Roddenberry Stem Cell Center, San Francisco, CA 94158, USA
| | - Yu Huang
- Gladstone Institute of Cardiovascular Disease and Roddenberry Stem Cell Center, San Francisco, CA 94158, USA
| | - Arye Elfenbein
- Gladstone Institute of Cardiovascular Disease and Roddenberry Stem Cell Center, San Francisco, CA 94158, USA
| | - Amy Foley
- Gladstone Institute of Cardiovascular Disease and Roddenberry Stem Cell Center, San Francisco, CA 94158, USA
| | - Sergey Magnitsky
- Department of Radiology, University of California San Francisco, San Francisco, CA 94158, USA
| | - Deepak Srivastava
- Gladstone Institute of Cardiovascular Disease and Roddenberry Stem Cell Center, San Francisco, CA 94158, USA; Department of Pediatrics, University of California San Francisco, San Francisco, CA 94158, USA; Department of Biochemistry & Biophysics, University of California San Francisco, San Francisco, CA 94158, USA.
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Ang YS, Rivas RN, Ribeiro AJS, Srivas R, Rivera J, Stone NR, Pratt K, Mohamed TMA, Fu JD, Spencer CI, Tippens ND, Li M, Narasimha A, Radzinsky E, Moon-Grady AJ, Yu H, Pruitt BL, Snyder MP, Srivastava D. Disease Model of GATA4 Mutation Reveals Transcription Factor Cooperativity in Human Cardiogenesis. Cell 2017; 167:1734-1749.e22. [PMID: 27984724 DOI: 10.1016/j.cell.2016.11.033] [Citation(s) in RCA: 153] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 08/09/2016] [Accepted: 11/17/2016] [Indexed: 12/12/2022]
Abstract
Mutation of highly conserved residues in transcription factors may affect protein-protein or protein-DNA interactions, leading to gene network dysregulation and human disease. Human mutations in GATA4, a cardiogenic transcription factor, cause cardiac septal defects and cardiomyopathy. Here, iPS-derived cardiomyocytes from subjects with a heterozygous GATA4-G296S missense mutation showed impaired contractility, calcium handling, and metabolic activity. In human cardiomyocytes, GATA4 broadly co-occupied cardiac enhancers with TBX5, another transcription factor that causes septal defects when mutated. The GATA4-G296S mutation disrupted TBX5 recruitment, particularly to cardiac super-enhancers, concomitant with dysregulation of genes related to the phenotypic abnormalities, including cardiac septation. Conversely, the GATA4-G296S mutation led to failure of GATA4 and TBX5-mediated repression at non-cardiac genes and enhanced open chromatin states at endothelial/endocardial promoters. These results reveal how disease-causing missense mutations can disrupt transcriptional cooperativity, leading to aberrant chromatin states and cellular dysfunction, including those related to morphogenetic defects.
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Affiliation(s)
- Yen-Sin Ang
- Gladstone Institute of Cardiovascular Disease and Roddenberry Center for Stem Cell Biology and Medicine, San Francisco, CA 94158, USA; Department of Pediatrics, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Renee N Rivas
- Gladstone Institute of Cardiovascular Disease and Roddenberry Center for Stem Cell Biology and Medicine, San Francisco, CA 94158, USA; Department of Pediatrics, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94143, USA
| | | | - Rohith Srivas
- Department of Genetics and Center for Genomics and Personalized Medicine, Stanford University, Stanford, CA 94305, USA
| | - Janell Rivera
- Gladstone Institute of Cardiovascular Disease and Roddenberry Center for Stem Cell Biology and Medicine, San Francisco, CA 94158, USA
| | - Nicole R Stone
- Gladstone Institute of Cardiovascular Disease and Roddenberry Center for Stem Cell Biology and Medicine, San Francisco, CA 94158, USA; Department of Pediatrics, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Karishma Pratt
- Gladstone Institute of Cardiovascular Disease and Roddenberry Center for Stem Cell Biology and Medicine, San Francisco, CA 94158, USA
| | - Tamer M A Mohamed
- Gladstone Institute of Cardiovascular Disease and Roddenberry Center for Stem Cell Biology and Medicine, San Francisco, CA 94158, USA; Department of Pediatrics, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Ji-Dong Fu
- Gladstone Institute of Cardiovascular Disease and Roddenberry Center for Stem Cell Biology and Medicine, San Francisco, CA 94158, USA
| | - C Ian Spencer
- Gladstone Institute of Cardiovascular Disease and Roddenberry Center for Stem Cell Biology and Medicine, San Francisco, CA 94158, USA
| | - Nathaniel D Tippens
- Department of Biological Statistics and Computational Biology, Cornell University, Ithaca, NY 14850, USA
| | - Molong Li
- Gladstone Institute of Cardiovascular Disease and Roddenberry Center for Stem Cell Biology and Medicine, San Francisco, CA 94158, USA
| | - Anil Narasimha
- Department of Genetics and Center for Genomics and Personalized Medicine, Stanford University, Stanford, CA 94305, USA
| | - Ethan Radzinsky
- Gladstone Institute of Cardiovascular Disease and Roddenberry Center for Stem Cell Biology and Medicine, San Francisco, CA 94158, USA
| | - Anita J Moon-Grady
- Department of Pediatrics, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Haiyuan Yu
- Department of Biological Statistics and Computational Biology, Cornell University, Ithaca, NY 14850, USA
| | - Beth L Pruitt
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Michael P Snyder
- Department of Genetics and Center for Genomics and Personalized Medicine, Stanford University, Stanford, CA 94305, USA
| | - Deepak Srivastava
- Gladstone Institute of Cardiovascular Disease and Roddenberry Center for Stem Cell Biology and Medicine, San Francisco, CA 94158, USA; Department of Pediatrics, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94143, USA.
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Ribeiro AJS, Schwab O, Mandegar MA, Ang YS, Conklin BR, Srivastava D, Pruitt BL. Multi-Imaging Method to Assay the Contractile Mechanical Output of Micropatterned Human iPSC-Derived Cardiac Myocytes. Circ Res 2017; 120:1572-1583. [PMID: 28400398 DOI: 10.1161/circresaha.116.310363] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 04/07/2017] [Accepted: 04/11/2017] [Indexed: 01/19/2023]
Abstract
RATIONALE During each beat, cardiac myocytes (CMs) generate the mechanical output necessary for heart function through contractile mechanisms that involve shortening of sarcomeres along myofibrils. Human-induced pluripotent stem cells (hiPSCs) can be differentiated into CMs (hiPSC-CMs) that model cardiac contractile mechanical output more robustly when micropatterned into physiological shapes. Quantifying the mechanical output of these cells enables us to assay cardiac activity in a dish. OBJECTIVE We sought to develop a computational platform that integrates analytic approaches to quantify the mechanical output of single micropatterned hiPSC-CMs from microscopy videos. METHODS AND RESULTS We micropatterned single hiPSC-CMs on deformable polyacrylamide substrates containing fluorescent microbeads. We acquired videos of single beating cells, of microbead displacement during contractions, and of fluorescently labeled myofibrils. These videos were independently analyzed to obtain parameters that capture the mechanical output of the imaged single cells. We also developed novel methods to quantify sarcomere length from videos of moving myofibrils and to analyze loss of synchronicity of beating in cells with contractile defects. We tested this computational platform by detecting variations in mechanical output induced by drugs and in cells expressing low levels of myosin-binding protein C. CONCLUSIONS Our method can measure the cardiac function of single micropatterned hiPSC-CMs and determine contractile parameters that can be used to elucidate mechanisms that underlie variations in CM function. This platform will be amenable to future studies of the effects of mutations and drugs on cardiac function.
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Affiliation(s)
- Alexandre J S Ribeiro
- From the Department of Mechanical Engineering (A.J.S.R., O.S., B.L.P.), Department of Molecular and Cellular Physiology (by courtesy) (B.L.P.), Department of Bioengineering (by courtesy) (B.L.P.), and Stanford Cardiovascular Institute (A.J.S.R., B.L.P.), Stanford University, CA; Gladstone Institute of Cardiovascular Disease, San Francisco, CA (A.J.S.R., M.A.M., Y.-S.A., B.R.C., D.S.); Roddenberry Stem Cell Center at Gladstone, San Francisco, CA (Y.-S.A., D.S.); Departments of Pediatrics and Biochemistry & Biophysics (D.S.), Department of Cellular and Molecular Pharmacology (B.R.C.), California Institute for Quantitative Biosciences, QB3 (B.R.C.), and Department of Medicine and Cellular and Molecular Pharmacology (B.R.C.), University of California, San Francisco
| | - Olivier Schwab
- From the Department of Mechanical Engineering (A.J.S.R., O.S., B.L.P.), Department of Molecular and Cellular Physiology (by courtesy) (B.L.P.), Department of Bioengineering (by courtesy) (B.L.P.), and Stanford Cardiovascular Institute (A.J.S.R., B.L.P.), Stanford University, CA; Gladstone Institute of Cardiovascular Disease, San Francisco, CA (A.J.S.R., M.A.M., Y.-S.A., B.R.C., D.S.); Roddenberry Stem Cell Center at Gladstone, San Francisco, CA (Y.-S.A., D.S.); Departments of Pediatrics and Biochemistry & Biophysics (D.S.), Department of Cellular and Molecular Pharmacology (B.R.C.), California Institute for Quantitative Biosciences, QB3 (B.R.C.), and Department of Medicine and Cellular and Molecular Pharmacology (B.R.C.), University of California, San Francisco
| | - Mohammad A Mandegar
- From the Department of Mechanical Engineering (A.J.S.R., O.S., B.L.P.), Department of Molecular and Cellular Physiology (by courtesy) (B.L.P.), Department of Bioengineering (by courtesy) (B.L.P.), and Stanford Cardiovascular Institute (A.J.S.R., B.L.P.), Stanford University, CA; Gladstone Institute of Cardiovascular Disease, San Francisco, CA (A.J.S.R., M.A.M., Y.-S.A., B.R.C., D.S.); Roddenberry Stem Cell Center at Gladstone, San Francisco, CA (Y.-S.A., D.S.); Departments of Pediatrics and Biochemistry & Biophysics (D.S.), Department of Cellular and Molecular Pharmacology (B.R.C.), California Institute for Quantitative Biosciences, QB3 (B.R.C.), and Department of Medicine and Cellular and Molecular Pharmacology (B.R.C.), University of California, San Francisco
| | - Yen-Sin Ang
- From the Department of Mechanical Engineering (A.J.S.R., O.S., B.L.P.), Department of Molecular and Cellular Physiology (by courtesy) (B.L.P.), Department of Bioengineering (by courtesy) (B.L.P.), and Stanford Cardiovascular Institute (A.J.S.R., B.L.P.), Stanford University, CA; Gladstone Institute of Cardiovascular Disease, San Francisco, CA (A.J.S.R., M.A.M., Y.-S.A., B.R.C., D.S.); Roddenberry Stem Cell Center at Gladstone, San Francisco, CA (Y.-S.A., D.S.); Departments of Pediatrics and Biochemistry & Biophysics (D.S.), Department of Cellular and Molecular Pharmacology (B.R.C.), California Institute for Quantitative Biosciences, QB3 (B.R.C.), and Department of Medicine and Cellular and Molecular Pharmacology (B.R.C.), University of California, San Francisco
| | - Bruce R Conklin
- From the Department of Mechanical Engineering (A.J.S.R., O.S., B.L.P.), Department of Molecular and Cellular Physiology (by courtesy) (B.L.P.), Department of Bioengineering (by courtesy) (B.L.P.), and Stanford Cardiovascular Institute (A.J.S.R., B.L.P.), Stanford University, CA; Gladstone Institute of Cardiovascular Disease, San Francisco, CA (A.J.S.R., M.A.M., Y.-S.A., B.R.C., D.S.); Roddenberry Stem Cell Center at Gladstone, San Francisco, CA (Y.-S.A., D.S.); Departments of Pediatrics and Biochemistry & Biophysics (D.S.), Department of Cellular and Molecular Pharmacology (B.R.C.), California Institute for Quantitative Biosciences, QB3 (B.R.C.), and Department of Medicine and Cellular and Molecular Pharmacology (B.R.C.), University of California, San Francisco
| | - Deepak Srivastava
- From the Department of Mechanical Engineering (A.J.S.R., O.S., B.L.P.), Department of Molecular and Cellular Physiology (by courtesy) (B.L.P.), Department of Bioengineering (by courtesy) (B.L.P.), and Stanford Cardiovascular Institute (A.J.S.R., B.L.P.), Stanford University, CA; Gladstone Institute of Cardiovascular Disease, San Francisco, CA (A.J.S.R., M.A.M., Y.-S.A., B.R.C., D.S.); Roddenberry Stem Cell Center at Gladstone, San Francisco, CA (Y.-S.A., D.S.); Departments of Pediatrics and Biochemistry & Biophysics (D.S.), Department of Cellular and Molecular Pharmacology (B.R.C.), California Institute for Quantitative Biosciences, QB3 (B.R.C.), and Department of Medicine and Cellular and Molecular Pharmacology (B.R.C.), University of California, San Francisco
| | - Beth L Pruitt
- From the Department of Mechanical Engineering (A.J.S.R., O.S., B.L.P.), Department of Molecular and Cellular Physiology (by courtesy) (B.L.P.), Department of Bioengineering (by courtesy) (B.L.P.), and Stanford Cardiovascular Institute (A.J.S.R., B.L.P.), Stanford University, CA; Gladstone Institute of Cardiovascular Disease, San Francisco, CA (A.J.S.R., M.A.M., Y.-S.A., B.R.C., D.S.); Roddenberry Stem Cell Center at Gladstone, San Francisco, CA (Y.-S.A., D.S.); Departments of Pediatrics and Biochemistry & Biophysics (D.S.), Department of Cellular and Molecular Pharmacology (B.R.C.), California Institute for Quantitative Biosciences, QB3 (B.R.C.), and Department of Medicine and Cellular and Molecular Pharmacology (B.R.C.), University of California, San Francisco.
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9
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Mohamed TMA, Stone NR, Berry EC, Radzinsky E, Huang Y, Pratt K, Ang YS, Yu P, Wang H, Tang S, Magnitsky S, Ding S, Ivey KN, Srivastava D. Chemical Enhancement of In Vitro and In Vivo Direct Cardiac Reprogramming. Circulation 2016; 135:978-995. [PMID: 27834668 DOI: 10.1161/circulationaha.116.024692] [Citation(s) in RCA: 159] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 10/21/2016] [Indexed: 12/22/2022]
Abstract
BACKGROUND Reprogramming of cardiac fibroblasts into induced cardiomyocyte-like cells in situ represents a promising strategy for cardiac regeneration. A combination of 3 cardiac transcription factors, Gata4, Mef2c, and Tbx5 (GMT), can convert fibroblasts into induced cardiomyocyte-like cells, albeit with low efficiency in vitro. METHODS We screened 5500 compounds in primary cardiac fibroblasts to identify the pathways that can be modulated to enhance cardiomyocyte reprogramming. RESULTS We found that a combination of the transforming growth factor-β inhibitor SB431542 and the WNT inhibitor XAV939 increased reprogramming efficiency 8-fold when added to GMT-overexpressing cardiac fibroblasts. The small molecules also enhanced the speed and quality of cell conversion; we observed beating cells as early as 1 week after reprogramming compared with 6 to 8 weeks with GMT alone. In vivo, mice exposed to GMT, SB431542, and XAV939 for 2 weeks after myocardial infarction showed significantly improved reprogramming and cardiac function compared with those exposed to only GMT. Human cardiac reprogramming was similarly enhanced on transforming growth factor-β and WNT inhibition and was achieved most efficiently with GMT plus myocardin. CONCLUSIONS Transforming growth factor-β and WNT inhibitors jointly enhance GMT-induced direct cardiac reprogramming from cardiac fibroblasts in vitro and in vivo and provide a more robust platform for cardiac regeneration.
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Affiliation(s)
- Tamer M A Mohamed
- From Gladstone Institute of Cardiovascular Disease and Roddenberry Center for Stem Cell Biology and Medicine, San Francisco, CA (T.M.A.M., N.R.S., E.C.B., E.R., Y.H., K.P., Y.-S.A., P.Y., H.W., S.T., S.D., K.N.I., D.S.); Institute of Cardiovascular Sciences, University of Manchester, UK (T.M.A.M.); Faculty of Pharmacy, Zagazig University, Egypt (T.M.A.M.); and Departments of Radiology (S.M.), Pharmaceutical Chemistry (S.D.), Pediatrics (K.N.I., D.S.), and Biochemistry and Biophysics (D.S.), University of California San Francisco
| | - Nicole R Stone
- From Gladstone Institute of Cardiovascular Disease and Roddenberry Center for Stem Cell Biology and Medicine, San Francisco, CA (T.M.A.M., N.R.S., E.C.B., E.R., Y.H., K.P., Y.-S.A., P.Y., H.W., S.T., S.D., K.N.I., D.S.); Institute of Cardiovascular Sciences, University of Manchester, UK (T.M.A.M.); Faculty of Pharmacy, Zagazig University, Egypt (T.M.A.M.); and Departments of Radiology (S.M.), Pharmaceutical Chemistry (S.D.), Pediatrics (K.N.I., D.S.), and Biochemistry and Biophysics (D.S.), University of California San Francisco
| | - Emily C Berry
- From Gladstone Institute of Cardiovascular Disease and Roddenberry Center for Stem Cell Biology and Medicine, San Francisco, CA (T.M.A.M., N.R.S., E.C.B., E.R., Y.H., K.P., Y.-S.A., P.Y., H.W., S.T., S.D., K.N.I., D.S.); Institute of Cardiovascular Sciences, University of Manchester, UK (T.M.A.M.); Faculty of Pharmacy, Zagazig University, Egypt (T.M.A.M.); and Departments of Radiology (S.M.), Pharmaceutical Chemistry (S.D.), Pediatrics (K.N.I., D.S.), and Biochemistry and Biophysics (D.S.), University of California San Francisco
| | - Ethan Radzinsky
- From Gladstone Institute of Cardiovascular Disease and Roddenberry Center for Stem Cell Biology and Medicine, San Francisco, CA (T.M.A.M., N.R.S., E.C.B., E.R., Y.H., K.P., Y.-S.A., P.Y., H.W., S.T., S.D., K.N.I., D.S.); Institute of Cardiovascular Sciences, University of Manchester, UK (T.M.A.M.); Faculty of Pharmacy, Zagazig University, Egypt (T.M.A.M.); and Departments of Radiology (S.M.), Pharmaceutical Chemistry (S.D.), Pediatrics (K.N.I., D.S.), and Biochemistry and Biophysics (D.S.), University of California San Francisco
| | - Yu Huang
- From Gladstone Institute of Cardiovascular Disease and Roddenberry Center for Stem Cell Biology and Medicine, San Francisco, CA (T.M.A.M., N.R.S., E.C.B., E.R., Y.H., K.P., Y.-S.A., P.Y., H.W., S.T., S.D., K.N.I., D.S.); Institute of Cardiovascular Sciences, University of Manchester, UK (T.M.A.M.); Faculty of Pharmacy, Zagazig University, Egypt (T.M.A.M.); and Departments of Radiology (S.M.), Pharmaceutical Chemistry (S.D.), Pediatrics (K.N.I., D.S.), and Biochemistry and Biophysics (D.S.), University of California San Francisco
| | - Karishma Pratt
- From Gladstone Institute of Cardiovascular Disease and Roddenberry Center for Stem Cell Biology and Medicine, San Francisco, CA (T.M.A.M., N.R.S., E.C.B., E.R., Y.H., K.P., Y.-S.A., P.Y., H.W., S.T., S.D., K.N.I., D.S.); Institute of Cardiovascular Sciences, University of Manchester, UK (T.M.A.M.); Faculty of Pharmacy, Zagazig University, Egypt (T.M.A.M.); and Departments of Radiology (S.M.), Pharmaceutical Chemistry (S.D.), Pediatrics (K.N.I., D.S.), and Biochemistry and Biophysics (D.S.), University of California San Francisco
| | - Yen-Sin Ang
- From Gladstone Institute of Cardiovascular Disease and Roddenberry Center for Stem Cell Biology and Medicine, San Francisco, CA (T.M.A.M., N.R.S., E.C.B., E.R., Y.H., K.P., Y.-S.A., P.Y., H.W., S.T., S.D., K.N.I., D.S.); Institute of Cardiovascular Sciences, University of Manchester, UK (T.M.A.M.); Faculty of Pharmacy, Zagazig University, Egypt (T.M.A.M.); and Departments of Radiology (S.M.), Pharmaceutical Chemistry (S.D.), Pediatrics (K.N.I., D.S.), and Biochemistry and Biophysics (D.S.), University of California San Francisco
| | - Pengzhi Yu
- From Gladstone Institute of Cardiovascular Disease and Roddenberry Center for Stem Cell Biology and Medicine, San Francisco, CA (T.M.A.M., N.R.S., E.C.B., E.R., Y.H., K.P., Y.-S.A., P.Y., H.W., S.T., S.D., K.N.I., D.S.); Institute of Cardiovascular Sciences, University of Manchester, UK (T.M.A.M.); Faculty of Pharmacy, Zagazig University, Egypt (T.M.A.M.); and Departments of Radiology (S.M.), Pharmaceutical Chemistry (S.D.), Pediatrics (K.N.I., D.S.), and Biochemistry and Biophysics (D.S.), University of California San Francisco
| | - Haixia Wang
- From Gladstone Institute of Cardiovascular Disease and Roddenberry Center for Stem Cell Biology and Medicine, San Francisco, CA (T.M.A.M., N.R.S., E.C.B., E.R., Y.H., K.P., Y.-S.A., P.Y., H.W., S.T., S.D., K.N.I., D.S.); Institute of Cardiovascular Sciences, University of Manchester, UK (T.M.A.M.); Faculty of Pharmacy, Zagazig University, Egypt (T.M.A.M.); and Departments of Radiology (S.M.), Pharmaceutical Chemistry (S.D.), Pediatrics (K.N.I., D.S.), and Biochemistry and Biophysics (D.S.), University of California San Francisco
| | - Shibing Tang
- From Gladstone Institute of Cardiovascular Disease and Roddenberry Center for Stem Cell Biology and Medicine, San Francisco, CA (T.M.A.M., N.R.S., E.C.B., E.R., Y.H., K.P., Y.-S.A., P.Y., H.W., S.T., S.D., K.N.I., D.S.); Institute of Cardiovascular Sciences, University of Manchester, UK (T.M.A.M.); Faculty of Pharmacy, Zagazig University, Egypt (T.M.A.M.); and Departments of Radiology (S.M.), Pharmaceutical Chemistry (S.D.), Pediatrics (K.N.I., D.S.), and Biochemistry and Biophysics (D.S.), University of California San Francisco
| | - Sergey Magnitsky
- From Gladstone Institute of Cardiovascular Disease and Roddenberry Center for Stem Cell Biology and Medicine, San Francisco, CA (T.M.A.M., N.R.S., E.C.B., E.R., Y.H., K.P., Y.-S.A., P.Y., H.W., S.T., S.D., K.N.I., D.S.); Institute of Cardiovascular Sciences, University of Manchester, UK (T.M.A.M.); Faculty of Pharmacy, Zagazig University, Egypt (T.M.A.M.); and Departments of Radiology (S.M.), Pharmaceutical Chemistry (S.D.), Pediatrics (K.N.I., D.S.), and Biochemistry and Biophysics (D.S.), University of California San Francisco
| | - Sheng Ding
- From Gladstone Institute of Cardiovascular Disease and Roddenberry Center for Stem Cell Biology and Medicine, San Francisco, CA (T.M.A.M., N.R.S., E.C.B., E.R., Y.H., K.P., Y.-S.A., P.Y., H.W., S.T., S.D., K.N.I., D.S.); Institute of Cardiovascular Sciences, University of Manchester, UK (T.M.A.M.); Faculty of Pharmacy, Zagazig University, Egypt (T.M.A.M.); and Departments of Radiology (S.M.), Pharmaceutical Chemistry (S.D.), Pediatrics (K.N.I., D.S.), and Biochemistry and Biophysics (D.S.), University of California San Francisco
| | - Kathryn N Ivey
- From Gladstone Institute of Cardiovascular Disease and Roddenberry Center for Stem Cell Biology and Medicine, San Francisco, CA (T.M.A.M., N.R.S., E.C.B., E.R., Y.H., K.P., Y.-S.A., P.Y., H.W., S.T., S.D., K.N.I., D.S.); Institute of Cardiovascular Sciences, University of Manchester, UK (T.M.A.M.); Faculty of Pharmacy, Zagazig University, Egypt (T.M.A.M.); and Departments of Radiology (S.M.), Pharmaceutical Chemistry (S.D.), Pediatrics (K.N.I., D.S.), and Biochemistry and Biophysics (D.S.), University of California San Francisco
| | - Deepak Srivastava
- From Gladstone Institute of Cardiovascular Disease and Roddenberry Center for Stem Cell Biology and Medicine, San Francisco, CA (T.M.A.M., N.R.S., E.C.B., E.R., Y.H., K.P., Y.-S.A., P.Y., H.W., S.T., S.D., K.N.I., D.S.); Institute of Cardiovascular Sciences, University of Manchester, UK (T.M.A.M.); Faculty of Pharmacy, Zagazig University, Egypt (T.M.A.M.); and Departments of Radiology (S.M.), Pharmaceutical Chemistry (S.D.), Pediatrics (K.N.I., D.S.), and Biochemistry and Biophysics (D.S.), University of California San Francisco.
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10
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Spence JC, Purssell H, Large J, Hendriskz C, Ang YS. Endoscopy under general anaesthetic in patients with metabolic disorders. Br J Hosp Med (Lond) 2016; 77:664. [PMID: 27828740 DOI: 10.12968/hmed.2016.77.11.664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- J C Spence
- Medical Student Manchester Medical School Faculty of Medical and Human Sciences University of Manchester Manchester
| | - H Purssell
- Core Medical Trainee Department of Gastroenterology Salford Royal NHS Foundation Trust Salford Greater Manchester
| | - J Large
- Consultant Anaesthetist Department of Anaesthesiology Salford Royal NHS Foundation Trust Salford Greater Manchester
| | - C Hendriskz
- Consultant in Transitional Metabolic Medicine Department of Transitional and Adult Metabolic Disorders Salford Royal NHS Foundation Trust Salford Greater Manchester
| | - Y S Ang
- Consultant Gastroenterologist Department of Gastroenterology Salford Royal NHS Foundation Trust Salford M6 8HD
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11
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Ribeiro AJ, Ang YS, Wilson RE, Rivas RN, Srivastava D, Pruitt BL. A Tuned Tension Regulates the Contractility of Cardiomyocytes Differentiated from Induced Pluripotent Stem Cells. Biophys J 2016. [DOI: 10.1016/j.bpj.2015.11.1587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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12
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Affiliation(s)
- Yen-Sin Ang
- From the Gladstone Institute of Cardiovascular Disease and Roddenberry Stem Cell Center at Gladstone Institutes, San Francisco, CA (Y.-S.A., D.S.); and Departments of Pediatrics and Biochemistry and Biophysics, University of California, San Francisco (Y.-S.A., D.S.)
| | - Deepak Srivastava
- From the Gladstone Institute of Cardiovascular Disease and Roddenberry Stem Cell Center at Gladstone Institutes, San Francisco, CA (Y.-S.A., D.S.); and Departments of Pediatrics and Biochemistry and Biophysics, University of California, San Francisco (Y.-S.A., D.S.)
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13
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Ang YS, Yung LYL. Toehold-mediated internal control to probe the near-field interaction between the metallic nanoparticle and the fluorophore. Nanoscale 2014; 6:12515-12523. [PMID: 25238596 DOI: 10.1039/c4nr03643c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Metallic nanoparticles (MNPs) are known to alter the emission of vicinal fluorophores through the near-field interaction, leading to either fluorescence quenching or enhancement. Much ambiguity remains in the experimental outcome of such a near-field interaction, particularly for bulk colloidal solution. It is hypothesized that the strong far-field interference from the inner filter effect of the MNPs could mask the true near-field MNP-fluorophore interaction significantly. Thus, in this work, a reliable internal control capable of decoupling the near-field interaction from far-field interference is established by the use of the DNA toehold concept to mediate the in situ assembly and disassembly of the MNP-fluorophore conjugate. A model gold nanoparticle (AuNP)-Cy3 system is used to investigate our proposed toehold-mediated internal control system. The maximum fluorescence enhancement is obtained for large-sized AuNP (58 nm) separated from Cy3 at an intermediate distance of 6.8 nm, while fluorescence quenching is observed for smaller-sized AuNP (11 nm and 23 nm), which is in agreement with the theoretical values reported in the literature. This work shows that the toehold-mediated internal control design can serve as a central system for evaluating the near-field interaction of other MNP-fluorophore combinations and facilitate the rational design of specific MNP-fluorophore systems for various applications.
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Affiliation(s)
- Y S Ang
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 11920, Singapore.
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Xu H, Ang YS, Sevilla A, Lemischka IR, Ma'ayan A. Construction and validation of a regulatory network for pluripotency and self-renewal of mouse embryonic stem cells. PLoS Comput Biol 2014; 10:e1003777. [PMID: 25122140 PMCID: PMC4133156 DOI: 10.1371/journal.pcbi.1003777] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 06/27/2014] [Indexed: 11/22/2022] Open
Abstract
A 30-node signed and directed network responsible for self-renewal and pluripotency of mouse embryonic stem cells (mESCs) was extracted from several ChIP-Seq and knockdown followed by expression prior studies. The underlying regulatory logic among network components was then learned using the initial network topology and single cell gene expression measurements from mESCs cultured in serum/LIF or serum-free 2i/LIF conditions. Comparing the learned network regulatory logic derived from cells cultured in serum/LIF vs. 2i/LIF revealed differential roles for Nanog, Oct4/Pou5f1, Sox2, Esrrb and Tcf3. Overall, gene expression in the serum/LIF condition was more variable than in the 2i/LIF but mostly consistent across the two conditions. Expression levels for most genes in single cells were bimodal across the entire population and this motivated a Boolean modeling approach. In silico predictions derived from removal of nodes from the Boolean dynamical model were validated with experimental single and combinatorial RNA interference (RNAi) knockdowns of selected network components. Quantitative post-RNAi expression level measurements of remaining network components showed good agreement with the in silico predictions. Computational removal of nodes from the Boolean network model was also used to predict lineage specification outcomes. In summary, data integration, modeling, and targeted experiments were used to improve our understanding of the regulatory topology that controls mESC fate decisions as well as to develop robust directed lineage specification protocols. For this study we first constructed a directed and signed network consisting of 15 pluripotency regulators and 15 lineage commitment markers that extensively interact to regulate mouse embryonic stem cells fate decisions from data available in the public domain. Given the connectivity structure of this network, the underlying regulatory logic was learned using single cell gene expression measurements of mESCs cultured in two different conditions. With connectivity and logic learned, the network was then simulated using a dynamic Boolean logic framework. Such simulations enabled prediction of knockdown effects on the overall activity of the network. Such predictions were validated by single and combinatorial RNA interference experiments followed by expression measurements. Finally, lineage specification outcomes upon single and combinatorial gene knockdowns were predicted for all possible knockdown combinations.
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Affiliation(s)
- Huilei Xu
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Department of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Yen-Sin Ang
- Department of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Ana Sevilla
- Department of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Ihor R. Lemischka
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Department of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- * E-mail: (IRL); (AM)
| | - Avi Ma'ayan
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- * E-mail: (IRL); (AM)
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Heidersbach A, Saxby C, Carver-Moore K, Huang Y, Ang YS, de Jong PJ, Ivey KN, Srivastava D. microRNA-1 regulates sarcomere formation and suppresses smooth muscle gene expression in the mammalian heart. eLife 2013; 2:e01323. [PMID: 24252873 PMCID: PMC3833424 DOI: 10.7554/elife.01323] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
microRNA-1 (miR-1) is an evolutionarily conserved, striated muscle-enriched miRNA. Most mammalian genomes contain two copies of miR-1, and in mice, deletion of a single locus, miR-1-2, causes incompletely penetrant lethality and subtle cardiac defects. Here, we report that deletion of miR-1-1 resulted in a phenotype similar to that of the miR-1-2 mutant. Compound miR-1 knockout mice died uniformly before weaning due to severe cardiac dysfunction. miR-1-null cardiomyocytes had abnormal sarcomere organization and decreased phosphorylation of the regulatory myosin light chain-2 (MLC2), a critical cytoskeletal regulator. The smooth muscle-restricted inhibitor of MLC2 phosphorylation, Telokin, was ectopically expressed in the myocardium, along with other smooth muscle genes. miR-1 repressed Telokin expression through direct targeting and by repressing its transcriptional regulator, Myocardin. Our results reveal that miR-1 is required for postnatal cardiac function and reinforces the striated muscle phenotype by regulating both transcriptional and effector nodes of the smooth muscle gene expression network. DOI:http://dx.doi.org/10.7554/eLife.01323.001 MicroRNAs are tiny RNAs that do not encode proteins. Instead, they regulate the expression of genes by preventing protein-encoding messenger RNAs from being translated into protein. MicroRNAs are expressed throughout the body, including the heart, where the most abundant microRNA is called miR-1. This is encoded by two nearly identical genes: miR-1-1 and miR-1-2. Mice that lack the miR-1-2 gene have various heart abnormalities, but generally survive because they still produce some miR-1 from their remaining miR-1-1 gene. Now, Heidersbach et al. have generated the first mice that specifically lack both miR-1 genes, and shown that these animals die before weaning. When viewed under the electron microscope, heart muscle from miR-1 double knockout mice lacks the characteristic ‘striped’, or striated, appearance of normal heart muscle. Additionally, miR-1 double knockout hearts have some gene expression characteristics more similar to the smooth muscle found in the gut and in the walls of blood vessels. Smooth muscle differs from striated muscle in that it lacks sarcomeres: these are bands of fibrous proteins, such as myosin, that are essential for muscle contraction. In normal mice, an enzyme called MLCK contributes to the formation and function of sarcomeres by adding phosphate groups to myosin molecules. By contrast, in smooth muscle an enzyme called Telokin promotes phosphate group removal, and thus affects the function of sarcomeres. Heidersbach et al. showed that miR-1 interacts directly with Telokin mRNA to prevent its expression in the heart, and simultaneously represses a protein called Myocardin, which directly activates transcription of Telokin. However, when miR-1 is absent, as in the miR-1 double knockout mice, Telokin is expressed in heart muscle, along with many other genes characteristic of smooth muscle. As well as improving our understanding of the development and functioning of the heart, these findings should shed new light on the role of microRNAs in maintaining the patterns of gene expression that characterize unique cell fates. DOI:http://dx.doi.org/10.7554/eLife.01323.002
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Affiliation(s)
- Amy Heidersbach
- Gladstone Institute of Cardiovascular Disease, San Francisco, United States
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16
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Lee DF, Su J, Ang YS, Carvajal-Vergara X, Mulero-Navarro S, Pereira CF, Gingold J, Wang HL, Zhao R, Sevilla A, Darr H, Williamson AJK, Chang B, Niu X, Aguilo F, Flores ER, Sher YP, Hung MC, Whetton AD, Gelb BD, Moore KA, Snoeck HW, Ma'ayan A, Schaniel C, Lemischka IR. Regulation of embryonic and induced pluripotency by aurora kinase-p53 signaling. Cell Stem Cell 2013; 11:179-94. [PMID: 22862944 DOI: 10.1016/j.stem.2012.05.020] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Revised: 03/06/2012] [Accepted: 05/03/2012] [Indexed: 12/28/2022]
Abstract
Many signals must be integrated to maintain self-renewal and pluripotency in embryonic stem cells (ESCs) and to enable induced pluripotent stem cell (iPSC) reprogramming. However, the exact molecular regulatory mechanisms remain elusive. To unravel the essential internal and external signals required for sustaining the ESC state, we conducted a short hairpin (sh) RNA screen of 104 ESC-associated phosphoregulators. Depletion of one such molecule, aurora kinase A (Aurka), resulted in compromised self-renewal and consequent differentiation. By integrating global gene expression and computational analyses, we discovered that loss of Aurka leads to upregulated p53 activity that triggers ESC differentiation. Specifically, Aurka regulates pluripotency through phosphorylation-mediated inhibition of p53-directed ectodermal and mesodermal gene expression. Phosphorylation of p53 not only impairs p53-induced ESC differentiation but also p53-mediated suppression of iPSC reprogramming. Our studies demonstrate an essential role for Aurka-p53 signaling in the regulation of self-renewal, differentiation, and somatic cell reprogramming.
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Affiliation(s)
- Dung-Fang Lee
- Department of Developmental and Regenerative Biology and The Black Family Stem Cell Institute, Mount Sinai School of Medicine, New York, NY 10029, USA
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17
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Dibb M, Han N, Choudhury J, Hayes S, Valentine H, West C, Ang YS, Sharrocks AD. The FOXM1-PLK1 axis is commonly upregulated in oesophageal adenocarcinoma. Br J Cancer 2012; 107:1766-75. [PMID: 23037713 PMCID: PMC3493860 DOI: 10.1038/bjc.2012.424] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Revised: 08/29/2012] [Accepted: 08/29/2012] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND The transcription factor FOXM1 is an important regulator of the cell cycle through controlling periodic gene expression during the G2 and M phases. One key target for FOXM1 is the gene encoding the protein kinase PLK1 and PLK1 itself acts in a positive feedback loop to phosphorylate and activate FOXM1. Both FOXM1 and PLK1 have been shown to be overexpressed in a variety of different tumour types. METHODS We have used a combination of RT-PCR, western blotting, tissue microarrays and metadata analysis of microarray data to study whether the FOXM1-PLK1 regulatory axis is upregulated and operational in oesophageal adenocarcinoma. RESULTS FOXM1 and PLK1 are expressed in oesophageal adenocarcinoma-derived cell lines and demonstrate cross-regulatory interactions. Importantly, we also demonstrate the concomitant overexpression of FOXM1 and PLK1 in a large proportion of oesophageal adenocarcinoma samples. This co-association was extended to the additional FOXM1 target genes CCNB1, AURKB and CKS1. In a cohort of patients who subsequently underwent surgery, the expression of several FOXM1 target genes was prognostic for overall survival. CONCLUSIONS FOXM1 and its target gene PLK1 are commonly overexpressed in oesophageal adenocarcinomas and this association can be extended to other FOXM1 target genes, providing potentially important biomarkers for predicting post-surgery disease survival.
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Affiliation(s)
- M Dibb
- Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
- Faculty of Medical and Human Sciences, University of Manchester, Oxford Road, Manchester, UK
| | - N Han
- Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - J Choudhury
- Department of Histopathology, Salford Royal Foundation Trust, Stott Lane, Salford M6 8HD, UK
| | - S Hayes
- Faculty of Medical and Human Sciences, University of Manchester, Oxford Road, Manchester, UK
- Department of Histopathology, Salford Royal Foundation Trust, Stott Lane, Salford M6 8HD, UK
| | - H Valentine
- School of Cancer and Enabling Sciences, Manchester Academic Health Science Centre, The University of Manchester, Christie Hospital, Manchester, UK
| | - C West
- School of Cancer and Enabling Sciences, Manchester Academic Health Science Centre, The University of Manchester, Christie Hospital, Manchester, UK
| | - Y S Ang
- Faculty of Medical and Human Sciences, University of Manchester, Oxford Road, Manchester, UK
| | - A D Sharrocks
- Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
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18
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Fidalgo M, Shekar PC, Ang YS, Fujiwara Y, Orkin SH, Wang J. Zfp281 functions as a transcriptional repressor for pluripotency of mouse embryonic stem cells. Stem Cells 2012; 29:1705-16. [PMID: 21915945 PMCID: PMC3272666 DOI: 10.1002/stem.736] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Embryonic stem cells (ESCs) derived from preimplantation blastocysts have unique self-renewal and multilineage differentiation properties that are controlled by key components of a core regulatory network including Oct4, Sox2, and Nanog. Understanding molecular underpinnings of these properties requires identification and characterization of additional factors that act in conjunction with these key factors in ESCs. We have previously identified Zfp281, a Krüppel-like zinc finger transcription factor, as an interaction partner of Nanog. We now present detailed functional analyses of Zfp281 using a genetically ablated null allele in mouse ESCs. Our data show that while Zfp281 is dispensable for establishment and maintenance of ESCs, it is required for their proper differentiation in vitro. We performed microarray profiling in combination with previously published datasets of Zfp281 global target gene occupancy and found that Zfp281 mainly functions as a repressor to restrict expression of many stem cell pluripotency genes. In particular, we demonstrated that deletion of Zfp281 resulted in upregulation of Nanog at both the transcript and protein levels with concomitant compromised differentiation of ESCs during embryoid body culture. Chromatin immunoprecipitation experiments demonstrated that Zfp281 is required for Nanog binding to its own promoter, suggesting that Nanog-associated repressive complex(es) involving Zfp281 may fine-tune Nanog expression for pluripotency of ESCs.
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Affiliation(s)
- Miguel Fidalgo
- Department of Developmental and Regenerative Biology, Black Family Stem Cell Institute, Mount Sinai School of Medicine, New York 10029, USA
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19
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Tsai SY, Bouwman BA, Ang YS, Kim SJ, Lee DF, Lemischka IR, Rendl M. Single transcription factor reprogramming of hair follicle dermal papilla cells to induced pluripotent stem cells. Stem Cells 2011; 29:964-71. [PMID: 21563278 DOI: 10.1002/stem.649] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Reprogramming patient-specific somatic cells into induced pluripotent stem (iPS) cells has great potential to develop feasible regenerative therapies. However, several issues need to be resolved such as ease, efficiency, and safety of generation of iPS cells. Many different cell types have been reprogrammed, most conveniently even peripheral blood mononuclear cells. However, they typically require the enforced expression of several transcription factors, posing mutagenesis risks as exogenous genetic material. To reduce this risk, iPS cells were previously generated with Oct4 alone from rather inaccessible neural stem cells that endogenously express the remaining reprogramming factors and very recently from fibroblasts with Oct4 alone in combination with additional small molecules. Here, we exploit that dermal papilla (DP) cells from hair follicles in the skin express all but one reprogramming factors to show that these accessible cells can be reprogrammed into iPS cells with the single transcription factor Oct4 and without further manipulation. Reprogramming was already achieved after 3 weeks and with efficiencies similar to other cell types reprogrammed with four factors. Dermal papilla-derived iPS cells are comparable to embryonic stem cells with respect to morphology, gene expression, and pluripotency. We conclude that DP cells may represent a preferred cell type for reprogramming accessible cells with less manipulation and for ultimately establishing safe conditions in the future by replacing Oct4 with small molecules.
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Affiliation(s)
- Su-Yi Tsai
- Black Family Stem Cell Institute, Mount Sinai School of Medicine, New York, New York 10029, USA
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20
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Keld R, Guo B, Downey P, Cummins R, Gulmann C, Ang YS, Sharrocks AD. PEA3/ETV4-related transcription factors coupled with active ERK signalling are associated with poor prognosis in gastric adenocarcinoma. Br J Cancer 2011; 105:124-30. [PMID: 21673681 PMCID: PMC3137405 DOI: 10.1038/bjc.2011.187] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Background: Transcription factors often play important roles in tumourigenesis. Members of the PEA3 subfamily of ETS-domain transcription factors fulfil such a role and have been associated with tumour metastasis in several different cancers. Moreover, the activity of the PEA3 subfamily transcription factors is potentiated by Ras-ERK pathway signalling, which is itself often deregulated in tumour cells. Methods: Immunohistochemical patterns of PEA3 expression and active ERK signalling were analysed and mRNA expression levels of PEA3, ER81, MMP-1 and MMP-7 were determined in gastric adenocarcinoma samples. Results: Here, we have studied the expression of the PEA3 subfamily members PEA3/ETV4 and ER81/ETV1 in gastric adenocarcinomas. PEA3 is upregulated at the protein level in gastric adenocarcinomas and both PEA3/ETV4 and ER81/ETV1 are upregulated at the mRNA level in gastric adenocarcinoma tissues. This increased expression correlates with the expression of a target gene associated with metastasis, MMP-1. Enhanced ERK signalling is also more prevalent in late-stage gastric adenocarcinomas, and the co-association of ERK signalling and PEA3 expression also occurs in late-stage gastric adenocarcinomas. Furthermore, the co-association of ERK signalling and PEA3 expression correlates with decreased survival rates. Conclusions: This study shows that members of the PEA3 subfamily of transcription factors are upregulated in gastric adenocarcinomas and that the simultaneous upregulation of PEA3 expression and ERK pathway signalling is indicative of late-stage disease and a poor survival prognosis.
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Affiliation(s)
- R Keld
- Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
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21
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Ang YS, Gaspar-Maia A, Lemischka IR, Bernstein E. Stem cells and reprogramming: breaking the epigenetic barrier? Trends Pharmacol Sci 2011; 32:394-401. [PMID: 21621281 DOI: 10.1016/j.tips.2011.03.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Revised: 03/01/2011] [Accepted: 03/02/2011] [Indexed: 01/25/2023]
Abstract
Increasing evidence suggests that epigenetic regulation is key to the maintenance of the stem cell state. Chromatin is the physiological form of eukaryotic genomes and the substrate for epigenetic marking, including DNA methylation, post-translational modifications of histones and the exchange of core histones with histone variants. The chromatin template undergoes significant reorganization during embryonic stem cell (ESC) differentiation and somatic cell reprogramming (SCR). Intriguingly, remodeling of the epigenome appears to be a crucial barrier that must be surmounted for efficient SCR. This area of research has gained significant attention due to the importance of ESCs in modeling and treating human disease. Here we review the epigenetic mechanisms that are key for maintenance of the ESC state, ESC differentiation and SCR. We focus on murine and human ESCs and induced pluripotent stem cells, and highlight the pharmacological approaches used to study or manipulate cell fate where relevant.
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Affiliation(s)
- Yen-Sin Ang
- Black Family Stem Cell Institute, Mount Sinai School of Medicine, 1425 Madison Avenue, New York, NY 10029, USA
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22
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Ang YS, Tsai SY, Lee DF, Monk J, Su J, Ratnakumar K, Ding J, Ge Y, Darr H, Chang B, Wang J, Rendl M, Bernstein E, Schaniel C, Lemischka IR. Wdr5 mediates self-renewal and reprogramming via the embryonic stem cell core transcriptional network. Cell 2011; 145:183-97. [PMID: 21477851 DOI: 10.1016/j.cell.2011.03.003] [Citation(s) in RCA: 435] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Revised: 12/22/2010] [Accepted: 02/09/2011] [Indexed: 11/24/2022]
Abstract
The embryonic stem (ES) cell transcriptional and chromatin-modifying networks are critical for self-renewal maintenance. However, it remains unclear whether these networks functionally interact and, if so, what factors mediate such interactions. Here, we show that WD repeat domain 5 (Wdr5), a core member of the mammalian Trithorax (trxG) complex, positively correlates with the undifferentiated state and is a regulator of ES cell self-renewal. We demonstrate that Wdr5, an "effector" of H3K4 methylation, interacts with the pluripotency transcription factor Oct4. Genome-wide protein localization and transcriptome analyses demonstrate overlapping gene regulatory functions between Oct4 and Wdr5. The Oct4-Sox2-Nanog circuitry and trxG cooperate in activating transcription of key self-renewal regulators, and furthermore, Wdr5 expression is required for the efficient formation of induced pluripotent stem (iPS) cells. We propose an integrated model of transcriptional and epigenetic control, mediated by select trxG members, for the maintenance of ES cell self-renewal and somatic cell reprogramming.
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Affiliation(s)
- Yen-Sin Ang
- Black Family Stem Cell Institute, Mount Sinai School of Medicine, New York, NY 10029, USA.
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23
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Carvajal-Vergara X, Sevilla A, D'Souza SL, Ang YS, Schaniel C, Lee DF, Yang L, Kaplan AD, Adler ED, Rozov R, Ge Y, Cohen N, Edelmann LJ, Chang B, Waghray A, Su J, Pardo S, Lichtenbelt KD, Tartaglia M, Gelb BD, Lemischka IR. Patient-specific induced pluripotent stem-cell-derived models of LEOPARD syndrome. Nature 2010; 465:808-12. [PMID: 20535210 PMCID: PMC2885001 DOI: 10.1038/nature09005] [Citation(s) in RCA: 504] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2009] [Accepted: 03/08/2010] [Indexed: 12/23/2022]
Abstract
Generation of reprogrammed induced pluripotent stem cells (iPSC) from patients with defined genetic disorders promises important avenues to understand the etiologies of complex diseases, and the development of novel therapeutic interventions. We have generated iPSC from patients with LEOPARD syndrome (LS; acronym of its main features: Lentigines, Electrocardiographic abnormalities, Ocular hypertelorism, Pulmonary valve stenosis, Abnormal genitalia, Retardation of growth and Deafness), an autosomal dominant developmental disorder belonging to a relatively prevalent class of inherited RAS-MAPK signaling diseases, which also includes Noonan syndrome (NS), with pleiomorphic effects on several tissues and organ systems1,2. The patient-derived cells have a mutation in the PTPN11 gene, which encodes the SHP2 phosphatase. The iPSC have been extensively characterized and produce multiple differentiated cell lineages. A major disease phenotype in patients with LEOPARD syndrome is hypertrophic cardiomyopathy. We show that in vitro-derived cardiomyocytes from LS-iPSC are larger, have a higher degree of sarcomeric organization and preferential localization of NFATc4 in the nucleus when compared to cardiomyocytes derived from human embryonic stem cells (HESC) or wild type (wt) iPSC derived from a healthy brother of one of the LS patients. These features correlate with a potential hypertrophic state. We also provide molecular insights into signaling pathways that may promote the disease phenotype.
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Affiliation(s)
- Xonia Carvajal-Vergara
- Department of Gene and Cell Medicine, Black Family Stem Cell Institute, Mount Sinai School of Medicine, New York, New York 10029, USA.
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24
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Tsai SY, Clavel C, Kim S, Ang YS, Grisanti L, Lee DF, Kelley K, Rendl M. Oct4 and klf4 reprogram dermal papilla cells into induced pluripotent stem cells. Stem Cells 2010; 28:221-8. [PMID: 20014278 DOI: 10.1002/stem.281] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Direct reprogramming of somatic cells into induced pluripotent stem (iPS) cells by only four transcription factors (Oct4, Sox2, Klf4, and c-Myc) has great potential for tissue-specific regenerative therapies, eliminating the ethical issues surrounding the use of embryonic stem cells and the rejection problems of using non-autologous cells. The reprogramming efficiency generally is very low, however, and the problems surrounding the introduction of viral genetic material are only partially investigated. Recent efforts to reduce the number of virally expressed transcription factors succeeded at reprogramming neural stem cells into iPS cells by overexpressing Oct4 alone. However, the relative inaccessibility and difficulty of obtaining neural cells in humans remains to be resolved. Here we report that dermal papilla (DP) cells, which are specialized skin fibroblasts thought to instruct hair follicle stem cells, endogenously express high levels of Sox2 and c-Myc, and that these cells can be reprogrammed into iPS cells with only Oct4 and Klf4. Moreover, we show that DP cells are reprogrammed more efficiently than skin and embryonic fibroblasts. iPS cells derived from DP cells expressed pluripotency genes and differentiated into cells from all germ layers in vitro and widely contributed to chimeric mice in vivo, including the germline. Our work establishes DP cells as an easily accessible source to generate iPS cells with efficiency and with less genetic material. This opens up the possibility of streamlined generation of skin-derived, patient-specific pluripotent stem cells and of ultimately replacing the remaining two factors with small molecules for safe generation of transplantable cells.
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Affiliation(s)
- Su-Yi Tsai
- Black Family Stem Cell Institute,Mount Sinai School of Medicine, New York, New York 10029, USA
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25
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Schaniel C, Ang YS, Ratnakumar K, Cormier C, James T, Bernstein E, Lemischka IR, Paddison PJ. Smarcc1/Baf155 couples self-renewal gene repression with changes in chromatin structure in mouse embryonic stem cells. Stem Cells 2010; 27:2979-91. [PMID: 19785031 DOI: 10.1002/stem.223] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Little is known about the molecular mechanism(s) governing differentiation decisions in embryonic stem cells (ESCs). To identify factors critical for ESC lineage formation, we carried out a functional genetic screen for factors affecting Nanog promoter activity during mESC differentiation. We report that members of the PBAF chromatin remodeling complex, including Smarca4/Brg1, Smarcb1/Baf47, Smarcc1/Baf155, and Smarce1/Baf57, are required for the repression of Nanog and other self-renewal gene expression upon mouse ESC (mESC) differentiation. Knockdown of Smarcc1 or Smarce1 suppressed loss of Nanog expression in multiple forms of differentiation. This effect occurred in the absence of self-renewal factors normally required for Nanog expression (e.g., Oct4), possibly indicating that changes in chromatin structure, rather than loss of self-renewal gene transcription per se, trigger differentiation. Consistent with this notion, mechanistic studies demonstrated that expression of Smarcc1 is necessary for heterochromatin formation and chromatin compaction during differentiation. Collectively, our data reveal that Smarcc1 plays important roles in facilitating mESCs differentiation by coupling gene repression with global and local changes in chromatin structure.
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Affiliation(s)
- Christoph Schaniel
- Black Family Stem Cell Institute, Department of Gene and Cell Medicine, New York, New York 10029, USA
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Abstract
Gastro-oesophageal reflux disease (GORD) is a common disorder which significantly impairs the quality of life. Recently an EndoCinch system has been described, with an approach to the treatment of GORD that would obviate the need for long-term proton pump inhibitors and the cost and potential risk of laparoscopic Nissen fundoplication. We set outto evaluate the status of this new technique for the management of GORD. We review the literatures (publications and abstracts) regarding safety, efficacy, and durability of this new antireflux procedure. On the whole, this new antireflux technique produced significant improvement in GORD symptomatology and quality of life and reduced the use of antireflux medication. However, it failed to normalize acid reflux, long-term durability data are lacking, and some serious side effects have been reported. In conclusion, EndoCinch has the potential to treat patients with this common ailment. However, further studies are necessary to determine what modifications to this antireflux technique are required in order to produce the maximum clinical benefit.
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Affiliation(s)
- Z Mahmood
- Department of Gastroenterology, West Cumberland Hospital, Whitehaven, UK.
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Tam WL, Lim CY, Han J, Zhang J, Ang YS, Ng HH, Yang H, Lim B. T-cell factor 3 regulates embryonic stem cell pluripotency and self-renewal by the transcriptional control of multiple lineage pathways. Stem Cells 2008; 26:2019-31. [PMID: 18467660 DOI: 10.1634/stemcells.2007-1115] [Citation(s) in RCA: 142] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The Wnt signaling pathway is necessary both for maintaining undifferentiated stem cells and for directing their differentiation. In mouse embryonic stem cells (ESCs), Wnt signaling preferentially maintains "stemness" under certain permissive conditions. T-cell factor 3 (Tcf3) is a component of the Wnt signaling and a dominant downstream effector in ESCs. Despite the wealth of knowledge regarding the importance of Wnt signaling underlying stem cells functions, the precise mechanistic explanation by which the effects are mediated is unknown. In this study, we identified new regulatory targets of Tcf3 using a whole-genome approach and found that Tcf3 transcriptionally represses many genes important for maintaining pluripotency and self-renewal, as well as those involved in lineage commitment and stem cell differentiation. This effect is in part mediated by the corepressors transducin-like enhancer of split 2 and C-terminal Binding Protein (CtBP). Notably, Tcf3 binds to and represses the Oct4 promoter, and this repressive effect requires both the Groucho and CtBP interacting domains of Tcf3. Interestingly, we find that in mouse preimplantation development embryos, Tcf3 expression is coregulated with Oct4 and Nanog and becomes localized to the inner cell mass of the blastocyst. These data demonstrate an important role for Tcf3 in modulating the appropriate level of gene transcription in ESCs and during embryonic development. Disclosure of potential conflicts of interest is found at the end of this article.
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Affiliation(s)
- Wai-Leong Tam
- Stem Cell and Developmental Biology, Genome Institute of Singapore, #02-01, Genome, Singapore
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28
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Tay YMS, Tam WL, Ang YS, Gaughwin PM, Yang H, Wang W, Liu R, George J, Ng HH, Perera RJ, Lufkin T, Rigoutsos I, Thomson AM, Lim B. MicroRNA-134 modulates the differentiation of mouse embryonic stem cells, where it causes post-transcriptional attenuation of Nanog and LRH1. Stem Cells 2007; 26:17-29. [PMID: 17916804 DOI: 10.1634/stemcells.2007-0295] [Citation(s) in RCA: 189] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Hundreds of microRNAs (miRNAs) are expressed in mammalian cells, where they aid in modulating gene expression by mediating mRNA transcript cleavage and/or regulation of translation rate. Functional studies to date have demonstrated that several of these miRNAs are important during development. However, the role of miRNAs in the regulation of stem cell growth and differentiation is not well understood. We show herein that microRNA (miR)-134 levels are maximally elevated at day 4 after retinoic acid-induced differentiation or day 2 after N2B27-induced differentiation of mouse embryonic stem cells (mESCs), but this change is not observed during embryoid body differentiation. The elevation of miR-134 levels alone in mESCs enhances differentiation toward ectodermal lineages, an effect that is blocked by a miR-134 antagonist. The promotion of mESC differentiation by miR-134 is due, in part, to its direct translational attenuation of Nanog and LRH1, both of which are known positive regulators of Oct4/POU5F1 and mESC growth. Together, the data demonstrate that miR-134 alone can enhance the differentiation of mESCs to ectodermal lineages and establish a functional role for miR-134 in modulating mESC differentiation through its potential to target and regulate multiple mRNAs.
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Affiliation(s)
- Yvonne M-S Tay
- Stem Cell and Developmental Biology, Genome Institute of Singapore, #02-01 Genome, Singapore 138672
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Mahmood Z, Zaheer A, Ang YS, Mahmud N. Endocinch treatment for gastro-oesophageal reflux (GORD): retention of plications are essential to control GORD. Gut 2007; 56:1027; author reply 1027. [PMID: 17566040 PMCID: PMC1994387 DOI: 10.1136/gut.2007.122978] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
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Abstract
Ageing is often defined in the context of telomerase activity and telomere length regulation. Most somatic cells have limited replication ability and undergo senescence eventually. Stem cells are unique as they possess more abundant telomerase activity and are able to maintain telomere lengths for a longer period. Embryonic stem cells are particularly resistant to ageing and can be propagated indefinitely. Remarkably, adult somatic cells can be reprogrammed to an ESC-like state by various means including cell fusion, exposure to ESC cell-free extracts, enforced expression of specific molecules, and somatic cell nuclear transfer. Thus, the rejuvenation of an 'aged' state can be effected by the activation of specific key molecules in the cell. Here, we argue that cellular ageing is a reversible process, and this is determined by the balance of biological molecules which directly or indirectly control telomere length and telomerase activity, either through altering gene expression and/or modulating the epigenetic state of the chromatin.
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Affiliation(s)
- Wai-Leong Tam
- Stem Cell & Developmental Biology, Genome Institute of Singapore, Singapore 138672, Singapore
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Miranda KC, Huynh T, Tay Y, Ang YS, Tam WL, Thomson AM, Lim B, Rigoutsos I. A pattern-based method for the identification of MicroRNA binding sites and their corresponding heteroduplexes. Cell 2006; 126:1203-17. [PMID: 16990141 DOI: 10.1016/j.cell.2006.07.031] [Citation(s) in RCA: 1482] [Impact Index Per Article: 82.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2006] [Revised: 06/16/2006] [Accepted: 07/26/2006] [Indexed: 12/12/2022]
Abstract
We present rna22, a method for identifying microRNA binding sites and their corresponding heteroduplexes. Rna22 does not rely upon cross-species conservation, is resilient to noise, and, unlike previous methods, it first finds putative microRNA binding sites in the sequence of interest, then identifies the targeting microRNA. Computationally, we show that rna22 identifies most of the currently known heteroduplexes. Experimentally, with luciferase assays, we demonstrate average repressions of 30% or more for 168 of 226 tested targets. The analysis suggests that some microRNAs may have as many as a few thousand targets, and that between 74% and 92% of the gene transcripts in four model genomes are likely under microRNA control through their untranslated and amino acid coding regions. We also extended the method's key idea to a low-error microRNA-precursor-discovery scheme; our studies suggest that the number of microRNA precursors in mammalian genomes likely ranges in the tens of thousands.
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Affiliation(s)
- Kevin C Miranda
- Bioinformatics and Pattern Discovery Group, IBM Thomas J. Watson Research Center, Yorktown Heights, P.O. Box 218, NY 10598, USA
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Ang YS, Farrell RJ. Risk of lymphoma: inflammatory bowel disease and immunomodulators. Gut 2006; 55:580-1. [PMID: 16531538 PMCID: PMC1856179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
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Chew JL, Loh YH, Zhang W, Chen X, Tam WL, Yeap LS, Li P, Ang YS, Lim B, Robson P, Ng HH. Reciprocal transcriptional regulation of Pou5f1 and Sox2 via the Oct4/Sox2 complex in embryonic stem cells. Mol Cell Biol 2005; 25:6031-46. [PMID: 15988017 PMCID: PMC1168830 DOI: 10.1128/mcb.25.14.6031-6046.2005] [Citation(s) in RCA: 505] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Embryonic stem cells (ESCs) are pluripotent cells that can either self-renew or differentiate into many cell types. Oct4 and Sox2 are transcription factors essential to the pluripotent and self-renewing phenotypes of ESCs. Both factors are upstream in the hierarchy of the transcription regulatory network and are partners in regulating several ESC-specific genes. In ESCs, Sox2 is transcriptionally regulated by an enhancer containing a composite sox-oct element that Oct4 and Sox2 bind in a combinatorial interaction. It has previously been shown that Pou5f1, the Oct4 gene, contains a distal enhancer imparting specific expression in both ESCs and preimplantation embryos. Here, we identify a composite sox-oct element within this enhancer and show that it is involved in Pou5f1 transcriptional activity in ESCs. In vitro experiments with ESC nuclear extracts demonstrate that Oct4 and Sox2 interact specifically with this regulatory element. More importantly, by chromatin immunoprecipitation assay, we establish that both Oct4 and Sox2 bind directly to the composite sox-oct elements in both Pou5f1 and Sox2 in living mouse and human ESCs. Specific knockdown of either Oct4 or Sox2 by RNA interference leads to the reduction of both genes' enhancer activities and endogenous expression levels in addition to ESC differentiation. Our data uncover a positive and potentially self-reinforcing regulatory loop that maintains Pou5f1 and Sox2 expression via the Oct4/Sox2 complex in pluripotent cells.
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Affiliation(s)
- Joon-Lin Chew
- Department of Biological Sciences, National University of Singapore
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Windle HJ, Ang YS, Athie-Morales V, Morales VA, McManus R, Kelleher D. Human peripheral and gastric lymphocyte responses to Helicobacter pylori NapA and AphC differ in infected and uninfected individuals. Gut 2005; 54:25-32. [PMID: 15591500 PMCID: PMC1774350 DOI: 10.1136/gut.2003.025494] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND In this study, we identify the nature of the immunological response of human peripheral blood mononuclear cells (PBMC) and lamina propria gastric lymphocytes (LPL) to two Helicobacter pylori antigens, the neutrophil activating protein (NapA) and alkyl hydroperoxide reductase (AphC). These antigens were identified and selected for study based on the observation that serological recognition of these proteins was associated with H pylori negative status in humans. AIMS The aim was to study the serological, proliferative, and cytokine responses of PBMC and LPL, obtained from H pylori infected and uninfected individuals, to these antigens. METHODS Patient serum, PBMC, and LPL were used to determine antibody isotype, and proliferative and cytokine responses to recombinant forms of NapA and AphC using western blotting and ELISA. RESULTS Western blotting revealed antibody reactivity to recombinant NapA and AphC among the H pylori negative population studied. Both the proliferative and interferon gamma responses of PBMC and LPL to NapA and AphC were significantly higher in H pylori negative compared with H pylori positive subjects. Analysis of the IgG subclass profiles to both antigens revealed a T helper 1 associated IgG3 antibody response in uninfected individuals. However, interleukin 10 production was greater in H pylori positive individuals in response to these antigens. CONCLUSIONS Taken together these data are consistent with an immune response to these antigens skewed towards a T helper 1 response in the uninfected cohort.
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Affiliation(s)
- H J Windle
- Trinity Centre for Health Sciences, Department of Clinical Medicine, St James's Hospital, Dublin 8, Ireland.
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Abdel-Latif MMM, Windle HJ, Fitzgerald KA, Ang YS, Eidhin DN, Li-Weber M, Sabra K, Kelleher D. Helicobacter pylori activates the early growth response 1 protein in gastric epithelial cells. Infect Immun 2004; 72:3549-60. [PMID: 15155664 PMCID: PMC415651 DOI: 10.1128/iai.72.6.3549-3560.2004] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The early growth response 1 (Egr-1) transcription factor is rapidly induced by various stimuli and is implicated in the regulation of cell growth, differentiation, and gene expression. The aim of this study was to examine the effect of Helicobacter pylori on the expression of Egr-1 and Egr-1-regulated genes in gastric epithelial AGS cells. Egr-1 expression was assayed by immunoblotting and electrophoretic mobility shift assays using H. pylori-stimulated AGS cells. Transient transfection experiments with promoter-reporter constructs of CD44, ICAM-1, and CD95L were used for expression studies. H. pylori induced the expression of Egr-1 in gastric epithelial cell lines in a dose-dependent manner, with the rapid kinetics that are typical of this class of transcription factors. Immunohistochemical studies of biopsies revealed that Egr-1 expression is more abundant in H. pylori-positive patients than in uninfected individuals. Reporter-promoter transfection studies indicated that Egr-1 binding is required for the H. pylori-induced transcriptional promoter activity of the CD44, ICAM-1, and CD95L (APO-1/Fas) constructs. The blocking of egr-1 with an antisense sequence prevented H. pylori-induced Egr-1 and CD44 protein expression. The MEK1/2 signaling cascade participates in H. pylori-mediated Egr-1 expression, but the p38 pathway does not. The data indicate that H. pylori induces Egr-1 expression in AGS cells in vitro and that the Egr-1 protein is readily detectable in biopsies from H. pylori-positive subjects. These observations suggest that H. pylori-associated Egr-1 expression may play a role, in part, in H. pylori-induced pathology.
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Affiliation(s)
- M M M Abdel-Latif
- Department of Clinical Medicine and Dublin Molecular Medicine Centre, Trinity Centre for Health Sciences, St. James's Hospital, Dublin 8, Ireland.
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Ang YS, Mahmud N, White B, Byrne M, Kelly A, Lawler M, McDonald GS, Smith OP, Keeling PW. Randomized comparison of unfractionated heparin with corticosteroids in severe active inflammatory bowel disease. Aliment Pharmacol Ther 2000; 14:1015-22. [PMID: 10930895 DOI: 10.1046/j.1365-2036.2000.00802.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Heparin therapy may be effective in steroid resistant inflammatory bowel disease. AIM A randomized pilot study, to compare unfractionated heparin as a first-line therapy with corticosteroids in colonic inflammatory bowel disease. METHODS Twenty patients with severe inflammatory bowel disease (ulcerative colitis, n=17; Crohn's colitis, n=3) were randomized to either intravenous heparin for 5 days, followed by subcutaneous heparin for 5 weeks (n=8), or high-dose intravenous hydrocortisone for 5 days followed by oral prednisolone 40 mg daily, reducing by 5 mg per day each week (n=12). After 5 days, non-responders in each treatment group were commenced on combination therapy. Response to therapy was monitored by: clinical disease activity (ulcerative colitis: Truelove and Witt Index; Crohn's colitis: Harvey and Bradshaw Index), stool frequency, serum C-reactive protein and alpha1 acid glycoprotein, endoscopic and histopathological grading. RESULTS The response rates were similar in both treatment groups: clinical activity index (heparin vs. steroid; 75% vs. 67%; P=0.23), stool frequency (75% vs. 67%; P=0.61), endoscopic (75% vs. 67%; P=0.4) and histopathological grading (63% vs. 50%; P=0.67). Both treatments were well-tolerated with no serious adverse events. CONCLUSION Heparin as a first line therapy is as effective as corticosteroids in the treatment of colonic inflammatory bowel disease. Large multicentre randomized comparative studies are required to determine the role of heparin in the management of inflammatory bowel disease.
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Affiliation(s)
- Y S Ang
- Department of Clinical Medicine, Trinity College Dublin, Ireland
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