1
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Narayan G, Sen P, Nagotu S, Thummer RP. Biological activity of recombinant human PDX1 protein produced from Escherichia coli. J Biochem Mol Toxicol 2023; 37:e23511. [PMID: 37632262 DOI: 10.1002/jbt.23511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 08/11/2023] [Accepted: 08/17/2023] [Indexed: 08/27/2023]
Abstract
Pancreatic and duodenum homeobox 1 (PDX1) is considered as a pivotal transcription factor that acts as a "master regulator" in pancreatogenesis and maintenance of β-cells. Earlier study has reported that PDX1 also functions as a tumor suppressor in human gastric cancer cells by inhibiting cell growth. Here, we report the bioactivity of the purified human PDX1 fusion protein using various assays like cell migration, proliferation, cell cycle analysis, and gene expression. In cancer cells, recombinant PDX1 protein reduced cell migration and proliferation, and arrested cell growth by inducing apoptosis in gastric cancer cells. In pancreatic ductal cancer cells, the application of the PDX1 protein resulted in the induction of insulin gene expression. The results of these experiments demonstrate the biological activity imparted by recombinant human PDX1 fusion protein on gastric and pancreatic cancer cells and its usefulness as a biological tool to elucidate its function in various cellular processes.
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Affiliation(s)
- Gloria Narayan
- Laboratory for Stem Cell Engineering and Regenerative Medicine, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India
| | - Plaboni Sen
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India
| | - Shirisha Nagotu
- Organelle Biology and Cellular Ageing Lab, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India
| | - Rajkumar P Thummer
- Laboratory for Stem Cell Engineering and Regenerative Medicine, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India
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2
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Bohuslavova R, Fabriciova V, Smolik O, Lebrón-Mora L, Abaffy P, Benesova S, Zucha D, Valihrach L, Berkova Z, Saudek F, Pavlinkova G. NEUROD1 reinforces endocrine cell fate acquisition in pancreatic development. Nat Commun 2023; 14:5554. [PMID: 37689751 PMCID: PMC10492842 DOI: 10.1038/s41467-023-41306-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Accepted: 08/30/2023] [Indexed: 09/11/2023] Open
Abstract
NEUROD1 is a transcription factor that helps maintain a mature phenotype of pancreatic β cells. Disruption of Neurod1 during pancreatic development causes severe neonatal diabetes; however, the exact role of NEUROD1 in the differentiation programs of endocrine cells is unknown. Here, we report a crucial role of the NEUROD1 regulatory network in endocrine lineage commitment and differentiation. Mechanistically, transcriptome and chromatin landscape analyses demonstrate that Neurod1 inactivation triggers a downregulation of endocrine differentiation transcription factors and upregulation of non-endocrine genes within the Neurod1-deficient endocrine cell population, disturbing endocrine identity acquisition. Neurod1 deficiency altered the H3K27me3 histone modification pattern in promoter regions of differentially expressed genes, which resulted in gene regulatory network changes in the differentiation pathway of endocrine cells, compromising endocrine cell potential, differentiation, and functional properties.
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Affiliation(s)
- Romana Bohuslavova
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology CAS, 25250, Vestec, Czechia
| | - Valeria Fabriciova
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology CAS, 25250, Vestec, Czechia
| | - Ondrej Smolik
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology CAS, 25250, Vestec, Czechia
| | - Laura Lebrón-Mora
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology CAS, 25250, Vestec, Czechia
| | - Pavel Abaffy
- Laboratory of Gene Expression, Institute of Biotechnology CAS, 25250, Vestec, Czechia
| | - Sarka Benesova
- Laboratory of Gene Expression, Institute of Biotechnology CAS, 25250, Vestec, Czechia
| | - Daniel Zucha
- Laboratory of Gene Expression, Institute of Biotechnology CAS, 25250, Vestec, Czechia
| | - Lukas Valihrach
- Laboratory of Gene Expression, Institute of Biotechnology CAS, 25250, Vestec, Czechia
| | - Zuzana Berkova
- Diabetes Centre, Experimental Medicine Centre, Institute for Clinical and Experimental Medicine, 14021, Prague, Czechia
| | - Frantisek Saudek
- Diabetes Centre, Experimental Medicine Centre, Institute for Clinical and Experimental Medicine, 14021, Prague, Czechia
| | - Gabriela Pavlinkova
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology CAS, 25250, Vestec, Czechia.
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3
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Yang X, Raum JC, Kim J, Yu R, Yang J, Rice G, Li C, Won KJ, Stanescu DE, Stoffers DA. A PDX1 cistrome and single-cell transcriptome resource of the developing pancreas. Development 2022; 149:dev200432. [PMID: 35708349 PMCID: PMC9340549 DOI: 10.1242/dev.200432] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 05/31/2022] [Indexed: 09/09/2023]
Abstract
Pancreatic and duodenal homeobox 1 (PDX1) is crucial for pancreas organogenesis, yet the dynamic changes in PDX1 binding in human or mouse developing pancreas have not been examined. To address this knowledge gap, we performed PDX1 ChIP-seq and single-cell RNA-seq using fetal human pancreata. We integrated our datasets with published datasets and revealed the dynamics of PDX1 binding and potential cell lineage-specific PDX1-bound genes in the pancreas from fetal to adult stages. We identified a core set of developmentally conserved PDX1-bound genes that reveal the broad multifaceted role of PDX1 in pancreas development. Despite the well-known dramatic changes in PDX1 function and expression, we found that PDX1-bound genes are largely conserved from embryonic to adult stages. This points towards a dual role of PDX1 in regulating the expression of its targets at different ages, dependent on other functionally congruent or directly interacting partners. We also showed that PDX1 binding is largely conserved in mouse pancreas. Together, our study reveals PDX1 targets in the developing pancreas in vivo and provides an essential resource for future studies on pancreas development.
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Affiliation(s)
- Xiaodun Yang
- Institute of Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jeffrey C. Raum
- Institute of Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Junil Kim
- School of Systems Biomedical Science, Soongsil University, 369 Sangdo-Ro, Dongjak-Gu, Seoul 06978, Republic of Korea
| | - Reynold Yu
- Institute of Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Juxiang Yang
- Division of Endocrinology and Diabetes, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Gabriella Rice
- Department of Cell and Developmental Biology, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Changhong Li
- Division of Endocrinology and Diabetes, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Kyoung-Jae Won
- Biotech Research & Innovation Centre, University of Copenhagen, Copenhagen 2200, Denmark
| | - Diana E. Stanescu
- Division of Endocrinology and Diabetes, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Doris A. Stoffers
- Institute of Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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4
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REST Inhibits Direct Reprogramming of Pancreatic Exocrine to Endocrine Cells by Preventing PDX1-Mediated Activation of Endocrine Genes. Cell Rep 2021; 31:107591. [PMID: 32375045 DOI: 10.1016/j.celrep.2020.107591] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 01/29/2020] [Accepted: 04/09/2020] [Indexed: 12/13/2022] Open
Abstract
The emerging appreciation of plasticity among pancreatic lineages has created interest in harnessing cellular reprogramming for β cell replacement therapy of diabetes. Current reprogramming methodologies are inefficient, largely because of a limited understanding of the underlying mechanisms. Using an in vitro reprogramming system, we reveal the transcriptional repressor RE-1 silencing transcription factor (REST) as a barrier for β cell gene expression in the reprogramming of pancreatic exocrine cells. We observe that REST-bound loci lie adjacent to the binding sites of multiple key β cell transcription factors, including PDX1. Accordingly, a loss of REST function combined with PDX1 expression results in the synergistic activation of endocrine genes. This is accompanied by increased histone acetylation and PDX1 binding at endocrine gene loci. Collectively, our data identify a mechanism for REST activity involving the prevention of PDX1-mediated activation of endocrine genes and uncover REST downregulation and the resulting chromatin alterations as key events in β cell reprogramming.
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5
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Gİrgİn B, KaradaĞ-Alpaslan M, KocabaŞ F. Oncogenic and tumor suppressor function of MEIS and associated factors. ACTA ACUST UNITED AC 2021; 44:328-355. [PMID: 33402862 PMCID: PMC7759197 DOI: 10.3906/biy-2006-25] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 08/13/2020] [Indexed: 12/14/2022]
Abstract
MEIS proteins are historically associated with tumorigenesis, metastasis, and invasion in cancer. MEIS and associated PBX-HOX proteins may act as tumor suppressors or oncogenes in different cellular settings. Their expressions tend to be misregulated in various cancers. Bioinformatic analyses have suggested their upregulation in leukemia/lymphoma, thymoma, pancreas, glioma, and glioblastoma, and downregulation in cervical, uterine, rectum, and colon cancers. However, every cancer type includes, at least, a subtype with high MEIS expression. In addition, studies have highlighted that MEIS proteins and associated factors may function as diagnostic or therapeutic biomarkers for various diseases. Herein, MEIS proteins and associated factors in tumorigenesis are discussed with recent discoveries in addition to how they could be modulated by noncoding RNAs or newly developed small-molecule MEIS inhibitors.
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Affiliation(s)
- Birkan Gİrgİn
- Regenerative Biology Research Laboratory, Department of Genetics and Bioengineering, Faculty of Engineering, Yeditepe University, İstanbul Turkey.,Graduate School of Natural and Applied Sciences, Yeditepe University, İstanbul Turkey.,Meinox Pharma Technologies, İstanbul Turkey
| | - Medine KaradaĞ-Alpaslan
- Department of Medical Genetics, Faculty of Medicine, Ondokuz Mayıs University, Samsun Turkey
| | - Fatih KocabaŞ
- Regenerative Biology Research Laboratory, Department of Genetics and Bioengineering, Faculty of Engineering, Yeditepe University, İstanbul Turkey.,Graduate School of Natural and Applied Sciences, Yeditepe University, İstanbul Turkey.,Meinox Pharma Technologies, İstanbul Turkey
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6
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Yong HJ, Xie G, Liu C, Wang W, Naji A, Irianto J, Wang YJ. Gene Signatures of NEUROGENIN3+ Endocrine Progenitor Cells in the Human Pancreas. Front Endocrinol (Lausanne) 2021; 12:736286. [PMID: 34566896 PMCID: PMC8456125 DOI: 10.3389/fendo.2021.736286] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 08/23/2021] [Indexed: 12/12/2022] Open
Abstract
NEUROGENIN3+ (NEUROG3+) cells are considered to be pancreatic endocrine progenitors. Our current knowledge on the molecular program of NEUROG3+ cells in humans is largely extrapolated from studies in mice. We hypothesized that single-cell RNA-seq enables in-depth exploration of the rare NEUROG3+ cells directly in humans. We aligned four large single-cell RNA-seq datasets from postnatal human pancreas. Our integrated analysis revealed 10 NEUROG3+ epithelial cells from a total of 11,174 pancreatic cells. Noticeably, human NEUROG3+ cells clustered with mature pancreatic cells and epsilon cells displayed the highest frequency of NEUROG3 positivity. We confirmed the co-expression of NEUROG3 with endocrine markers and the high percentage of NEUROG3+ cells among epsilon cells at the protein level based on immunostaining on pancreatic tissue sections. We further identified unique genetic signatures of the NEUROG3+ cells. Regulatory network inference revealed novel transcription factors including Prospero homeobox protein 1 (PROX1) may act jointly with NEUROG3. As NEUROG3 plays a central role in endocrine differentiation, knowledge gained from our study will accelerate the development of beta cell regeneration therapies to treat diabetes.
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Affiliation(s)
- Hyo Jeong Yong
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL, United States
| | - Gengqiang Xie
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL, United States
| | - Chengyang Liu
- Department of Surgery, Hospital of the University of Pennsylvania, Philadelphia, PA, United States
| | - Wei Wang
- Department of Surgery, Hospital of the University of Pennsylvania, Philadelphia, PA, United States
| | - Ali Naji
- Department of Surgery, Hospital of the University of Pennsylvania, Philadelphia, PA, United States
| | - Jerome Irianto
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL, United States
| | - Yue J. Wang
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL, United States
- *Correspondence: Yue J. Wang,
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7
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Guler GD, Ning Y, Ku CJ, Phillips T, McCarthy E, Ellison CK, Bergamaschi A, Collin F, Lloyd P, Scott A, Antoine M, Wang W, Chau K, Ashworth A, Quake SR, Levy S. Detection of early stage pancreatic cancer using 5-hydroxymethylcytosine signatures in circulating cell free DNA. Nat Commun 2020; 11:5270. [PMID: 33077732 PMCID: PMC7572413 DOI: 10.1038/s41467-020-18965-w] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Accepted: 09/18/2020] [Indexed: 12/15/2022] Open
Abstract
Pancreatic cancer is often detected late, when curative therapies are no longer possible. Here, we present non-invasive detection of pancreatic ductal adenocarcinoma (PDAC) by 5-hydroxymethylcytosine (5hmC) changes in circulating cell free DNA from a PDAC cohort (n = 64) in comparison with a non-cancer cohort (n = 243). Differential hydroxymethylation is found in thousands of genes, most significantly in genes related to pancreas development or function (GATA4, GATA6, PROX1, ONECUT1, MEIS2), and cancer pathogenesis (YAP1, TEAD1, PROX1, IGF1). cfDNA hydroxymethylome in PDAC cohort is differentially enriched for genes that are commonly de-regulated in PDAC tumors upon activation of KRAS and inactivation of TP53. Regularized regression models built using 5hmC densities in genes perform with AUC of 0.92 (discovery dataset, n = 79) and 0.92-0.94 (two independent test sets, n = 228). Furthermore, tissue-derived 5hmC features can be used to classify PDAC cfDNA (AUC = 0.88). These findings suggest that 5hmC changes enable classification of PDAC even during early stage disease.
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Affiliation(s)
- Gulfem D Guler
- Bluestar Genomics, 185 Berry Street, Lobby 4, Suite 210, San Francisco, CA, 94107, USA
| | - Yuhong Ning
- Bluestar Genomics, 185 Berry Street, Lobby 4, Suite 210, San Francisco, CA, 94107, USA
| | - Chin-Jen Ku
- Bluestar Genomics, 185 Berry Street, Lobby 4, Suite 210, San Francisco, CA, 94107, USA
| | - Tierney Phillips
- Bluestar Genomics, 10578 Science Center Drive Suite 210, San Diego, CA, 92121, USA
| | - Erin McCarthy
- Bluestar Genomics, 10578 Science Center Drive Suite 210, San Diego, CA, 92121, USA
| | | | - Anna Bergamaschi
- Bluestar Genomics, 10578 Science Center Drive Suite 210, San Diego, CA, 92121, USA
| | - Francois Collin
- Bluestar Genomics, 185 Berry Street, Lobby 4, Suite 210, San Francisco, CA, 94107, USA
| | - Paul Lloyd
- Bluestar Genomics, 185 Berry Street, Lobby 4, Suite 210, San Francisco, CA, 94107, USA
| | - Aaron Scott
- Bluestar Genomics, 185 Berry Street, Lobby 4, Suite 210, San Francisco, CA, 94107, USA
| | - Michael Antoine
- Bluestar Genomics, 10578 Science Center Drive Suite 210, San Diego, CA, 92121, USA
| | - Wendy Wang
- Bluestar Genomics, 10578 Science Center Drive Suite 210, San Diego, CA, 92121, USA
| | - Kim Chau
- Bluestar Genomics, 185 Berry Street, Lobby 4, Suite 210, San Francisco, CA, 94107, USA
| | - Alan Ashworth
- UCSF Helen Diller Family Comprehensive Cancer Center, San Francisco, CA, 94158, USA
| | - Stephen R Quake
- Departments of Bioengineering and Applied Physics, Stanford University, Stanford, CA, 94304, USA
- Chan Zuckerberg Biohub, San Francisco, CA, 94158, USA
| | - Samuel Levy
- Bluestar Genomics, 185 Berry Street, Lobby 4, Suite 210, San Francisco, CA, 94107, USA.
- Bluestar Genomics, 10578 Science Center Drive Suite 210, San Diego, CA, 92121, USA.
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8
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Schulte D, Geerts D. MEIS transcription factors in development and disease. Development 2019; 146:146/16/dev174706. [PMID: 31416930 DOI: 10.1242/dev.174706] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 06/28/2019] [Indexed: 12/12/2022]
Abstract
MEIS transcription factors are key regulators of embryonic development and cancer. Research on MEIS genes in the embryo and in stem cell systems has revealed novel and surprising mechanisms by which these proteins control gene expression. This Primer summarizes recent findings about MEIS protein activity and regulation in development, and discusses new insights into the role of MEIS genes in disease, focusing on the pathogenesis of solid cancers.
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Affiliation(s)
- Dorothea Schulte
- Institute of Neurology (Edinger Institute), University Hospital Frankfurt, Goethe University, 60528 Frankfurt, Germany
| | - Dirk Geerts
- Department of Medical Biology L2-109, Amsterdam University Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
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9
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Du X, Diao Y, Liu H, Li S. MsDBP: Exploring DNA-Binding Proteins by Integrating Multiscale Sequence Information via Chou’s Five-Step Rule. J Proteome Res 2019; 18:3119-3132. [DOI: 10.1021/acs.jproteome.9b00226] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Xiuquan Du
- The School of Computer Science and Technology, Anhui University, Hefei, Anhui, China
| | - Yanyu Diao
- The School of Computer Science and Technology, Anhui University, Hefei, Anhui, China
| | - Heng Liu
- Department of Gastroenterology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China
| | - Shuo Li
- Department of Medical Imaging, Western University, London, ON N6A 3K7, Canada
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10
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Oriente F, Perruolo G, Cimmino I, Cabaro S, Liotti A, Longo M, Miele C, Formisano P, Beguinot F. Prep1, A Homeodomain Transcription Factor Involved in Glucose and Lipid Metabolism. Front Endocrinol (Lausanne) 2018; 9:346. [PMID: 30002646 PMCID: PMC6032887 DOI: 10.3389/fendo.2018.00346] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 06/11/2018] [Indexed: 12/28/2022] Open
Abstract
The three-amino acid loop extension (TALE) homeodomain proteins are a family of transcription factor including the mammalian Pbx, MEIS and Prep proteins. TALE proteins can bind other transcription factors such as Pdx-1 and play an important role in the regulation of glucose metabolism. Experiments performed in mutant mice have shown that while the single Pbx1 or Pdx-1 knockout mice feature pancreatic islet malformations, impaired glucose tolerance and hypoinsulinemia, the trans-heterozygous Pbx1+/-Pdx1+/- mice develop age-dependent overt diabetes mellitus. In contrast, Prep1 plays a different role with respect to these proteins. Indeed, Prep1 hypomorphic mice, expressing low levels of protein, feature pancreatic islet hypoplasia accompanied by hypoinsulinemia similar to Pbx1 or Pdx1. Nevertheless, these animals show increased insulin sensitivity in skeletal muscle, liver and adipose tissue accompanied by protection from streptozotocin-induced diabetes. In addition, Prep1 hypomorphic mice feature reduced triglyceride synthesis and do not develop steatohepatitis after a methionine and coline deficient diet. In this review we have underlined how important metabolic functions are controlled by TALE proteins, in particular by Prep1, leading to hypothesis that its suppression might represent beneficial effect in the care of metabolic diseases.
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Affiliation(s)
- Francesco Oriente
- Department of Translational Medicine, Federico II University of Naples, Naples, Italy
- URT Genomic of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy
| | - Giuseppe Perruolo
- Department of Translational Medicine, Federico II University of Naples, Naples, Italy
- URT Genomic of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy
| | - Ilaria Cimmino
- Department of Translational Medicine, Federico II University of Naples, Naples, Italy
- URT Genomic of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy
| | - Serena Cabaro
- Department of Translational Medicine, Federico II University of Naples, Naples, Italy
- URT Genomic of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy
| | - Antonietta Liotti
- Department of Translational Medicine, Federico II University of Naples, Naples, Italy
- URT Genomic of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy
| | - Michele Longo
- Department of Translational Medicine, Federico II University of Naples, Naples, Italy
- URT Genomic of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy
| | - Claudia Miele
- Department of Translational Medicine, Federico II University of Naples, Naples, Italy
- URT Genomic of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy
| | - Pietro Formisano
- Department of Translational Medicine, Federico II University of Naples, Naples, Italy
- URT Genomic of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy
- *Correspondence: Pietro Formisano
| | - Francesco Beguinot
- Department of Translational Medicine, Federico II University of Naples, Naples, Italy
- URT Genomic of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy
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11
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Yang YP, Magnuson MA, Stein R, Wright CVE. The mammal-specific Pdx1 Area II enhancer has multiple essential functions in early endocrine cell specification and postnatal β-cell maturation. Development 2016; 144:248-257. [PMID: 27993987 DOI: 10.1242/dev.143123] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 12/07/2016] [Indexed: 01/19/2023]
Abstract
The transcription factor Pdx1 is required for multiple aspects of pancreatic organogenesis. It remains unclear to what extent Pdx1 expression and function depend upon trans-activation through 5' conserved cis-regulatory regions and, in particular, whether the mammal-specific Area II (-2139 to -1958 bp) affects minor or major aspects of organogenesis. We show that Area II is a primary effector of endocrine-selective transcription in epithelial multipotent cells, nascent endocrine progenitors, and differentiating and mature β cells in vivo Pdx1ΔAREAII/- mice exhibit a massive reduction in endocrine progenitor cells and progeny hormone-producing cells, indicating that Area II activity is fundamental to mounting an effective endocrine lineage-specification program within the multipotent cell population. Creating an Area II-deleted state within already specified Neurog3-expressing endocrine progenitor cells increased the proportion of glucagon+ α relative to insulin+ β cells, associated with the transcriptional and epigenetic derepression of the α-cell-determining Arx gene in endocrine progenitors. There were also glucagon and insulin co-expressing cells, and β cells that were incapable of maturation. Creating the Pdx1ΔAREAII state after cells entered an insulin-expressing stage led to immature and dysfunctional islet β cells carrying abnormal chromatin marking in vital β-cell-associated genes. Therefore, trans-regulatory integration through Area II mediates a surprisingly extensive range of progenitor and β-cell-specific Pdx1 functions.
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Affiliation(s)
- Yu-Ping Yang
- Vanderbilt University Program in Developmental Biology and Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232 USA.,Vanderbilt Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Mark A Magnuson
- Vanderbilt University Program in Developmental Biology and Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232 USA.,Vanderbilt Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Roland Stein
- Vanderbilt University Program in Developmental Biology and Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232 USA.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Christopher V E Wright
- Vanderbilt University Program in Developmental Biology and Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232 USA .,Vanderbilt Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA
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12
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Roy N, Takeuchi KK, Ruggeri JM, Bailey P, Chang D, Li J, Leonhardt L, Puri S, Hoffman MT, Gao S, Halbrook CJ, Song Y, Ljungman M, Malik S, Wright CVE, Dawson DW, Biankin AV, Hebrok M, Crawford HC. PDX1 dynamically regulates pancreatic ductal adenocarcinoma initiation and maintenance. Genes Dev 2016; 30:2669-2683. [PMID: 28087712 PMCID: PMC5238727 DOI: 10.1101/gad.291021.116] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 12/14/2016] [Indexed: 02/06/2023]
Abstract
Aberrant activation of embryonic signaling pathways is frequent in pancreatic ductal adenocarcinoma (PDA), making developmental regulators therapeutically attractive. Here we demonstrate diverse functions for pancreatic and duodenal homeobox 1 (PDX1), a transcription factor indispensable for pancreas development, in the progression from normal exocrine cells to metastatic PDA. We identify a critical role for PDX1 in maintaining acinar cell identity, thus resisting the formation of pancreatic intraepithelial neoplasia (PanIN)-derived PDA. Upon neoplastic transformation, the role of PDX1 changes from tumor-suppressive to oncogenic. Interestingly, subsets of malignant cells lose PDX1 expression while undergoing epithelial-to-mesenchymal transition (EMT), and PDX1 loss is associated with poor outcome. This stage-specific functionality arises from profound shifts in PDX1 chromatin occupancy from acinar cells to PDA. In summary, we report distinct roles of PDX1 at different stages of PDA, suggesting that therapeutic approaches against this potential target need to account for its changing functions at different stages of carcinogenesis. These findings provide insight into the complexity of PDA pathogenesis and advocate a rigorous investigation of therapeutically tractable targets at distinct phases of PDA development and progression.
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Affiliation(s)
- Nilotpal Roy
- Diabetes Center, Department of Medicine, University of California at San Francisco, San Francisco, California 94143, USA
| | - Kenneth K Takeuchi
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Jeanine M Ruggeri
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Peter Bailey
- Wolfson Wohl Cancer Research Center, University of Glasgow, Glasgow G61 1BD, Scotland
| | - David Chang
- Wolfson Wohl Cancer Research Center, University of Glasgow, Glasgow G61 1BD, Scotland
| | - Joey Li
- Diabetes Center, Department of Medicine, University of California at San Francisco, San Francisco, California 94143, USA
| | - Laura Leonhardt
- Diabetes Center, Department of Medicine, University of California at San Francisco, San Francisco, California 94143, USA
| | - Sapna Puri
- Diabetes Center, Department of Medicine, University of California at San Francisco, San Francisco, California 94143, USA
| | - Megan T Hoffman
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Shan Gao
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Christopher J Halbrook
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Yan Song
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York 11794, USA
| | - Mats Ljungman
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Shivani Malik
- Department of Medicine/ Hematology and Oncology, University of California at San Francisco, San Francisco, California 94143, USA
| | - Christopher V E Wright
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee 37240, USA
| | - David W Dawson
- Department of Pathology and Laboratory Medicine, University of California at Los Angeles, Los Angeles, California 90095, USA
| | - Andrew V Biankin
- Wolfson Wohl Cancer Research Center, University of Glasgow, Glasgow G61 1BD, Scotland
| | - Matthias Hebrok
- Diabetes Center, Department of Medicine, University of California at San Francisco, San Francisco, California 94143, USA
| | - Howard C Crawford
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48109, USA
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The Gene Regulatory Network of Lens Induction Is Wired through Meis-Dependent Shadow Enhancers of Pax6. PLoS Genet 2016; 12:e1006441. [PMID: 27918583 PMCID: PMC5137874 DOI: 10.1371/journal.pgen.1006441] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 10/21/2016] [Indexed: 01/03/2023] Open
Abstract
Lens induction is a classical developmental model allowing investigation of cell specification, spatiotemporal control of gene expression, as well as how transcription factors are integrated into highly complex gene regulatory networks (GRNs). Pax6 represents a key node in the gene regulatory network governing mammalian lens induction. Meis1 and Meis2 homeoproteins are considered as essential upstream regulators of Pax6 during lens morphogenesis based on their interaction with the ectoderm enhancer (EE) located upstream of Pax6 transcription start site. Despite this generally accepted regulatory pathway, Meis1-, Meis2- and EE-deficient mice have surprisingly mild eye phenotypes at placodal stage of lens development. Here, we show that simultaneous deletion of Meis1 and Meis2 in presumptive lens ectoderm results in arrested lens development in the pre-placodal stage, and neither lens placode nor lens is formed. We found that in the presumptive lens ectoderm of Meis1/Meis2 deficient embryos Pax6 expression is absent. We demonstrate using chromatin immunoprecipitation (ChIP) that in addition to EE, Meis homeoproteins bind to a remote, ultraconserved SIMO enhancer of Pax6. We further show, using in vivo gene reporter analyses, that the lens-specific activity of SIMO enhancer is dependent on the presence of three Meis binding sites, phylogenetically conserved from man to zebrafish. Genetic ablation of EE and SIMO enhancers demostrates their requirement for lens induction and uncovers an apparent redundancy at early stages of lens development. These findings identify a genetic requirement for Meis1 and Meis2 during the early steps of mammalian eye development. Moreover, they reveal an apparent robustness in the gene regulatory mechanism whereby two independent "shadow enhancers" maintain critical levels of a dosage-sensitive gene, Pax6, during lens induction.
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14
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The Promoter and Multiple Enhancers of the pou4f3 Gene Regulate Expression in Inner Ear Hair Cells. Mol Neurobiol 2016; 54:5414-5426. [PMID: 27592349 DOI: 10.1007/s12035-016-0060-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 08/16/2016] [Indexed: 12/21/2022]
Abstract
Few enhancers that target gene expression to inner ear hair cells (HCs) have been identified. Using transgenic analysis of enhanced green fluorescent protein (eGFP) reporter constructs and bioinformatics, we evaluated the control of pou4f3 gene expression, since it is expressed only in HCs within the inner ear and continues to be expressed throughout life. An 8.5-kb genomic DNA fragment 5' to the start codon, containing three regions of high cross-species homology, drove expression in all embryonic and neonatal HCs, and adult vestibular and inner HCs, but not adult outer HCs. Transgenes with 0.4, 0.8, 2.5, or 6.5 kb of 5' DNA did not produce HC expression. However, addition of the region from 6.5 to 7.2 kb produced expression in vestibular HCs and neonatal basal turn outer HCs, which also implicated the region from 7.2 to 8.5 kb in inner and apical outer HC expression. Deletion of the region from 0.4 to 5.5 kb 5' from the 8.5-kb construct did not affect HC expression, further indicating lack of HC regulatory elements. When the region from 1 to 0.4 kb was replaced with the minimal promoter of the Ela1 gene, HC expression was maintained but at a drastically reduced level. Bioinformatics identified regions of highly conserved sequence outside of the 8.5 kb, which contained POU4F3-, GFI1-, and LHX3-binding sites. These regions may be involved in maintaining POU4F3 expression in adult outer HCs. Our results identify separate enhancers at various locations that direct expression to different HC types at different ages and determine that 0.4 kb of upstream sequence determines expression level. These data will assist in the identification of mutations in noncoding, regulatory regions of this deafness gene.
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15
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Fujiwara N, Cave JW. Partial Conservation between Mice and Humans in Olfactory Bulb Interneuron Transcription Factor Codes. Front Neurosci 2016; 10:337. [PMID: 27489533 PMCID: PMC4951497 DOI: 10.3389/fnins.2016.00337] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 07/04/2016] [Indexed: 11/13/2022] Open
Abstract
The mammalian main olfactory bulb (OB) has a large population of GABAergic inhibitory interneurons that contains several subtypes defined by the co-expression other neurotransmitters and calcium binding proteins. The three most commonly studied OB interneuron subtypes co-express either Calretinin, Calbindin, or Tyrosine hydroxylase (Th). Combinations of transcription factors used to specify the phenotype of progenitors are referred to as transcription factor codes, and the current understanding of transcription factor codes that specify OB inhibitory neuron phenotypes are largely based on studies in mice. The conservation of these transcription factor codes in the human OB, however, has not been investigated. The aim of this study was to establish whether transcription factor codes in OB interneurons are conserved between mice and humans. This study compared the co-expression of Foxp2, Meis2, Pax6, and Sp8 transcription factors with Calretinin, Calbindin, or Th in human and mouse OB interneurons. This analysis found strong conservation of Calretinin co-expression with Sp8 and Meis2 as well as Th co-expression with Pax6 and Meis2. This analysis also showed that selective Foxp2 co-expression with Calbindin was conserved between mice and humans, which suggests Foxp2 is a novel determinant of the OB Calbindin interneuron phenotype. Together, the findings in this study provide insight into the conservation of transcription codes for OB interneuron phenotypes between humans and mice, as well as reveal some important differences between the species. This advance in our understanding of transcription factor codes in OB interneurons provides an important complement to the codes that have been established for other regions within the mammalian central nervous system, such as the cortex and spinal cord.
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Affiliation(s)
- Nana Fujiwara
- Burke Medical Research Institute White Plains, NY, USA
| | - John W Cave
- Burke Medical Research InstituteWhite Plains, NY, USA; The Feil Family Brain and Mind Research Institute, Weill Cornell MedicineNew York, NY, USA
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16
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Marty-Santos L, Cleaver O. Pdx1 regulates pancreas tubulogenesis and E-cadherin expression. Development 2015; 143:101-12. [PMID: 26657766 DOI: 10.1242/dev.126755] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 11/19/2015] [Indexed: 12/27/2022]
Abstract
Current efforts in developing treatments for diabetes focus on in vitro generation of functional β-cells for cell replacement therapies; however, these attempts have only been partly successful because factors involved in islet formation remain incompletely understood. The embryonic pancreas, which gives rise to β-cells, undergoes early epithelial rearrangements, including transient stratification of an initially monolayered epithelium, followed by microlumen formation and later resolution into branches. Within the epithelium, a multipotent progenitor cell (MPC) population is specified, giving rise to three important lineages: acinar, ductal and endocrine. Pdx1 is a transcription factor required for pancreas development and lineage specification; however, few Pdx1 targets that regulate pancreatogenesis have been identified. We find that pancreatic defects in Pdx1(-/-) embryos initiate at the time when the progenitor pool is specified and the epithelium should resolve into branches. Pdx1(-/-) microlumen diameters expand aberrantly, resulting in failure of epithelial tubulogenesis and ductal plexus formation. Pdx1(-/-) epithelial cell proliferation is decreased and the MPC pool is rapidly lost. We identify two conserved Pdx1 binding sites in the epithelial cadherin (E-cad, Cdh1) promoter, and show that Pdx1 directly binds and activates E-cad transcription. In addition, Pdx1 is required in vivo for maintenance of E-cad expression, actomyosin complex activity and cell shape. These findings demonstrate a novel link between regulators of epithelial architecture, specification of pancreatic cell fate and organogenesis.
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Affiliation(s)
- Leilani Marty-Santos
- Department of Molecular Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - Ondine Cleaver
- Department of Molecular Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
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17
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Golonzhka O, Nord A, Tang PLF, Lindtner S, Ypsilanti AR, Ferretti E, Visel A, Selleri L, Rubenstein JLR. Pbx Regulates Patterning of the Cerebral Cortex in Progenitors and Postmitotic Neurons. Neuron 2015; 88:1192-1207. [PMID: 26671461 DOI: 10.1016/j.neuron.2015.10.045] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 08/13/2015] [Accepted: 10/13/2015] [Indexed: 11/27/2022]
Abstract
We demonstrate using conditional mutagenesis that Pbx1, with and without Pbx2(+/-) sensitization, regulates regional identity and laminar patterning of the developing mouse neocortex in cortical progenitors (Emx1-Cre) and in newly generated neurons (Nex1-Cre). Pbx1/2 mutants have three salient molecular phenotypes of cortical regional and laminar organization: hypoplasia of the frontal cortex, ventral expansion of the dorsomedial cortex, and ventral expansion of Reelin expression in the cortical plate of the frontal cortex, concomitant with an inversion of cortical layering in the rostral cortex. Molecular analyses, including PBX ChIP-seq, provide evidence that PBX promotes frontal cortex identity by repressing genes that promote dorsocaudal fate.
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Affiliation(s)
- Olga Golonzhka
- Department of Psychiatry, Neuroscience Program and the Nina Ireland Laboratory of Developmental Neurobiology, University of California San Francisco, San Francisco, CA 94158, USA; Acetylon Pharmaceuticals, 70 Fargo Street, Suite 205, Boston, MA 02210, USA.
| | - Alex Nord
- Departments of Neurobiology, Physiology, and Behavior and Psychiatry and Behavioral Sciences, Center for Neuroscience, University of California Davis, Davis, CA 95618, USA
| | - Paul L F Tang
- Institute for Human Genetics, University of California San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA
| | - Susan Lindtner
- Department of Psychiatry, Neuroscience Program and the Nina Ireland Laboratory of Developmental Neurobiology, University of California San Francisco, San Francisco, CA 94158, USA
| | - Athena R Ypsilanti
- Department of Psychiatry, Neuroscience Program and the Nina Ireland Laboratory of Developmental Neurobiology, University of California San Francisco, San Francisco, CA 94158, USA
| | - Elisabetta Ferretti
- Department of Cell and Developmental Biology, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10021, USA; The Danish Stem Cell Center, University of Copenhagen, Blegdamsvej 3B, DK-2200 Copenhagen, Denmark
| | - Axel Visel
- Genomics Division, MS 84-171, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA 94598, USA; School of Natural Sciences, University of California, Merced, Merced, CA 95343, USA
| | - Licia Selleri
- Department of Cell and Developmental Biology, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10021, USA
| | - John L R Rubenstein
- Department of Psychiatry, Neuroscience Program and the Nina Ireland Laboratory of Developmental Neurobiology, University of California San Francisco, San Francisco, CA 94158, USA.
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Abstract
Studies in dopamine-depleted rats indicate that the external globus pallidus (GPe) contains two main types of GABAergic projection cell; so-called "prototypic" and "arkypallidal" neurons. Here, we used correlative anatomical and electrophysiological approaches in rats to determine whether and how this dichotomous organization applies to the dopamine-intact GPe. Prototypic neurons coexpressed the transcription factors Nkx2-1 and Lhx6, comprised approximately two-thirds of all GPe neurons, and were the major GPe cell type innervating the subthalamic nucleus (STN). In contrast, arkypallidal neurons expressed the transcription factor FoxP2, constituted just over one-fourth of GPe neurons, and innervated the striatum but not STN. In anesthetized dopamine-intact rats, molecularly identified prototypic neurons fired at relatively high rates and with high regularity, regardless of brain state (slow-wave activity or spontaneous activation). On average, arkypallidal neurons fired at lower rates and regularities than prototypic neurons, and the two cell types could be further distinguished by the temporal coupling of their firing to ongoing cortical oscillations. Complementing the activity differences observed in vivo, the autonomous firing of identified arkypallidal neurons in vitro was slower and more variable than that of prototypic neurons, which tallied with arkypallidal neurons displaying lower amplitudes of a "persistent" sodium current important for such pacemaking. Arkypallidal neurons also exhibited weaker driven and rebound firing compared with prototypic neurons. In conclusion, our data support the concept that a dichotomous functional organization, as actioned by arkypallidal and prototypic neurons with specialized molecular, structural, and physiological properties, is fundamental to the operations of the dopamine-intact GPe.
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19
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PDX1 binds and represses hepatic genes to ensure robust pancreatic commitment in differentiating human embryonic stem cells. Stem Cell Reports 2015; 4:578-90. [PMID: 25843046 PMCID: PMC4400640 DOI: 10.1016/j.stemcr.2015.02.015] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 02/23/2015] [Accepted: 02/23/2015] [Indexed: 12/30/2022] Open
Abstract
Inactivation of the Pancreatic and Duodenal Homeobox 1 (PDX1) gene causes pancreatic agenesis, which places PDX1 high atop the regulatory network controlling development of this indispensable organ. However, little is known about the identity of PDX1 transcriptional targets. We simulated pancreatic development by differentiating human embryonic stem cells (hESCs) into early pancreatic progenitors and subjected this cell population to PDX1 chromatin immunoprecipitation sequencing (ChIP-seq). We identified more than 350 genes bound by PDX1, whose expression was upregulated on day 17 of differentiation. This group included known PDX1 targets and many genes not previously linked to pancreatic development. ChIP-seq also revealed PDX1 occupancy at hepatic genes. We hypothesized that simultaneous PDX1-driven activation of pancreatic and repression of hepatic programs underlie early divergence between pancreas and liver. In HepG2 cells and differentiating hESCs, we found that PDX1 binds and suppresses expression of endogenous liver genes. These findings rebrand PDX1 as a context-dependent transcriptional repressor and activator within the same cell type. Early pancreatic progenitor (ePP) cells are efficiently derived from hESCs High levels of the homeobox transcription factor PDX1 label ePP cells PDX1 binds a battery of foregut/midgut and early pancreatic genes in ePP cells PDX1 binds and represses hepatic genes
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20
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AWAIS M, VORONINA SG, SUTTON R. An Efficient Method is Required to Transfect Non-dividing Cells with Genetically Encoded Optical Probes for Molecular Imaging. ANAL SCI 2015; 31:293-8. [DOI: 10.2116/analsci.31.293] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Muhammad AWAIS
- NIHR Liverpool Pancreas Biomedical Research Unit, Institute of Translational Medicine, The University of Liverpool, Royal Liverpool University Hospital
| | - Svetlana G VORONINA
- Department of Cellular and Molecular Physiology, The University of Liverpool
| | - Robert SUTTON
- NIHR Liverpool Pancreas Biomedical Research Unit, Institute of Translational Medicine, The University of Liverpool, Royal Liverpool University Hospital
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21
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Schulte D. Meis: New friends of Pax. NEUROGENESIS 2014; 1:e976014. [PMID: 27502016 PMCID: PMC4973581 DOI: 10.4161/23262133.2014.976014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 08/04/2014] [Accepted: 10/08/2014] [Indexed: 12/27/2022]
Abstract
The generation of neuronal diversity in the mammalian brain is a multistep process, beginning with the regional patterning of neural stem- and progenitor cell domains, the commitment of these cells toward a general neuronal fate, followed by the selection of a particular neuronal subtype and the differentiation of postmitotic neurons. Each of these steps as well as the transitions between them require precisely controlled changes in transcriptional programs. Although a large number of transcription factors are known to regulate neurogenesis in the embryonic and adult central nervous system, the sheer number of neuronal cell types in the brain and the complexity of the cellular processes that accompany their production suggest that transcription factors act cooperatively to control individual steps in neurogenesis. In fact, combinatorial regulation by sets of transcription factors has emerged as a versatile mode to control cell fate specification. Here, I discuss our recent finding that members of the MEIS-subfamily of TALE-transcription factors, originally identified as HOX cofactors in non-neural tissues, function in concert with PAX-proteins in the regulation of cell fate specification and neuronal differentiation in the embryonic and adult brain.
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Affiliation(s)
- Dorothea Schulte
- Institute of Neurology (Edinger Institute); University Hospital Goethe University ; Frankfurt, Germany
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22
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Brücher BLDM, Kitajima M, Siewert JR. Undervalued criteria in the evaluation of multimodal trials for upper GI cancers. Cancer Invest 2014; 32:497-506. [PMID: 25250506 PMCID: PMC4266078 DOI: 10.3109/07357907.2014.958497] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Global economies and their health systems face a huge challenge from cancer: 1 in 3 women and 1 in 2 men will develop cancer in their lifetime. In the less developed countries, the volume of cancer patients will overwhelm the existing healthcare systems. Even in developed regions, patients with upper gastrointestinal (GI) cancer usually present with locally advanced tumors that their prognosis is poor. A detailed knowledge of anatomy, embryology, epidemiology, tumor classifications and tumor growth is key understanding and evaluating the relevant research. We review undervalued criteria necessary to evaluate the response to multimodal therapy for upper GI cancers.
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Affiliation(s)
- Björn L D M Brücher
- Theodor-Billroth-Academy®, Munich, Germany; Richmond, VA, Sacramento, CA, USA,1
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23
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Brücher BL, Jamall IS. Epistemology of the origin of cancer: a new paradigm. BMC Cancer 2014; 14:331. [PMID: 24885752 PMCID: PMC4026115 DOI: 10.1186/1471-2407-14-331] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 05/06/2014] [Indexed: 02/06/2023] Open
Abstract
Background Carcinogenesis is widely thought to originate from somatic mutations and an inhibition of growth suppressors, followed by cell proliferation, tissue invasion, and risk of metastasis. Fewer than 10% of all cancers are hereditary; the ratio in gastric (1%), colorectal (3-5%) and breast (8%) cancers is even less. Cancers caused by infection are thought to constitute some 15% of the non-hereditary cancers. Those remaining, 70 to 80%, are called “sporadic,” because they are essentially of unknown etiology. We propose a new paradigm for the origin of the majority of cancers. Presentation of hypothesis Our paradigm postulates that cancer originates following a sequence of events that include (1) a pathogenic stimulus (biological or chemical) followed by (2) chronic inflammation, from which develops (3) fibrosis with associated changes in the cellular microenvironment. From these changes a (4) pre-cancerous niche develops, which triggers the deployment of (5) a chronic stress escape strategy, and when this fails to resolve, (6) a transition of a normal cell to a cancer cell occurs. If we are correct, this paradigm would suggest that the majority of the findings in cancer genetics so far reported are either late events or are epiphenomena that occur after the appearance of the pre-cancerous niche. Testing the hypothesis If, based on experimental and clinical findings presented here, this hypothesis is plausible, then the majority of findings in the genetics of cancer so far reported in the literature are late events or epiphenomena that could have occurred after the development of a PCN. Our model would make clear the need to establish preventive measures long before a cancer becomes clinically apparent. Future research should focus on the intermediate steps of our proposed sequence of events, which will enhance our understanding of the nature of carcinogenesis. Findings on inflammation and fibrosis would be given their warranted importance, with research in anticancer therapies focusing on suppressing the PCN state with very early intervention to detect and quantify any subclinical inflammatory change and to treat all levels of chronic inflammation and prevent fibrotic changes, and so avoid the transition from a normal cell to a cancer cell. Implication of the hypothesis The paradigm proposed here, if proven, spells out a sequence of steps, one or more of which could be interdicted or modulated early in carcinogenesis to prevent or, at a minimum, slow down the progression of many cancers.
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24
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Cerdá-Esteban N, Spagnoli FM. Glimpse into Hox and tale regulation of cell differentiation and reprogramming. Dev Dyn 2013; 243:76-87. [PMID: 24123411 DOI: 10.1002/dvdy.24075] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2013] [Revised: 09/15/2013] [Accepted: 10/04/2013] [Indexed: 12/20/2022] Open
Abstract
During embryonic development, cells become gradually restricted in their developmental potential and start elaborating lineage-specific transcriptional networks to ultimately acquire a unique differentiated state. Hox genes play a central role in specifying regional identities, thereby providing the cell with critical information on positional value along its differentiation path. The exquisite DNA-binding specificity of the Hox proteins is frequently dependent upon their interaction with members of the TALE family of homeodomain proteins. In addition to their function as Hox-cofactors, TALE homeoproteins control multiple crucial developmental processes through Hox-independent mechanisms. Here, we will review recent findings on the function of both Hox and TALE proteins in cell differentiation, referring mostly to vertebrate species. In addition, we will discuss the direct implications of this knowledge on cell plasticity and cell reprogramming.
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Affiliation(s)
- Nuria Cerdá-Esteban
- Laboratory of Molecular and Cellular Basis of Embryonic Development, Max Delbrück Center for Molecular Medicine, Berlin, Germany
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25
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Babin V, Wang D, Rose RB, Sagui C. Binding polymorphism in the DNA bound state of the Pdx1 homeodomain. PLoS Comput Biol 2013; 9:e1003160. [PMID: 23950697 PMCID: PMC3738460 DOI: 10.1371/journal.pcbi.1003160] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 06/13/2013] [Indexed: 11/18/2022] Open
Abstract
The subtle effects of DNA-protein recognition are illustrated in the homeodomain fold. This is one of several small DNA binding motifs that, in spite of limited DNA binding specificity, adopts crucial, specific roles when incorporated in a transcription factor. The homeodomain is composed of a 3-helix domain and a mobile N-terminal arm. Helix 3 (the recognition helix) interacts with the DNA bases through the major groove, while the N-terminal arm becomes ordered upon binding a specific sequence through the minor groove. Although many structural studies have characterized the DNA binding properties of homeodomains, the factors behind the binding specificity are still difficult to elucidate. A crystal structure of the Pdx1 homeodomain bound to DNA (PDB 2H1K) obtained previously in our lab shows two complexes with differences in the conformation of the N-terminal arm, major groove contacts, and backbone contacts, raising new questions about the DNA recognition process by homeodomains. Here, we carry out fully atomistic Molecular Dynamics simulations both in crystal and aqueous environments in order to elucidate the nature of the difference in binding contacts. The crystal simulations reproduce the X-ray experimental structures well. In the absence of crystal packing constraints, the differences between the two complexes increase during the solution simulations. Thus, the conformational differences are not an artifact of crystal packing. In solution, the homeodomain with a disordered N-terminal arm repositions to a partially specific orientation. Both the crystal and aqueous simulations support the existence of different stable binding conformers identified in the original crystallographic data with different degrees of specificity. We propose that protein-protein and protein-DNA interactions favor a subset of the possible conformations. This flexibility in DNA binding may facilitate multiple functions for the same transcription factor.
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Affiliation(s)
- Volodymyr Babin
- Center for High Performance Simulations (CHiPS) and Department of Physics, North Carolina State University, Raleigh, North Carolina, United States of America
- Department of Chemistry and Biochemistry, UC San Diego, La Jolla, California, United States of America
| | - Dongli Wang
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Robert B. Rose
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina, United States of America
- * E-mail: (RBR); (CS)
| | - Celeste Sagui
- Center for High Performance Simulations (CHiPS) and Department of Physics, North Carolina State University, Raleigh, North Carolina, United States of America
- * E-mail: (RBR); (CS)
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ICAT is a novel Ptf1a interactor that regulates pancreatic acinar differentiation and displays altered expression in tumours. Biochem J 2013; 451:395-405. [PMID: 23339455 DOI: 10.1042/bj20120873] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The PTF1 (pancreas transcription factor 1) complex is a master regulator of differentiation of acinar cells, responsible for the production of digestive enzymes. In the adult pancreas, PTF1 contains two pancreas-restricted transcription factors: Ptf1a and Rbpjl. PTF1 recruits P/CAF [p300/CREB (cAMP-response-element-binding protein)-binding protein-associated factor] which acetylates Ptf1a and enhances its transcriptional activity. Using yeast two-hybrid screening, we identified ICAT (inhibitor of β-catenin and Tcf4) as a novel Ptf1a interactor. ICAT regulates the Wnt pathway and cell proliferation. We validated and mapped the ICAT-Ptf1a interaction in vitro and in vivo. We demonstrated that, following its overexpression in acinar tumour cells, ICAT regulates negatively PTF1 activity in vitro and in vivo. This effect was independent of β-catenin and was mediated by direct binding to Ptf1a and displacement of P/CAF. ICAT also modulated the expression of Pdx1 and Sox9 in acinar tumour cells. ICAT overexpression reduced the interaction of Ptf1a with Rbpjl and P/CAF and impaired Ptf1a acetylation by P/CAF. ICAT did not affect the subcellular localization of Ptf1a. In human pancreas, ICAT displayed a cell-type-specific distribution; in acinar and endocrine cells, it was nuclear, whereas in ductal cells, it was cytoplasmic. In ductal adenocarcinomas, ICAT displayed mainly a nuclear or mixed distribution and the former was an independent marker of survival. ICAT regulates acinar differentiation and it does so through a novel Wnt pathway-independent mechanism that may contribute to pancreatic disease.
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27
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Matsuoka TA. Molecular mechanism of pancreatic β-cell dysfunction under diabetic conditions. Diabetol Int 2012. [DOI: 10.1007/s13340-012-0091-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Chen C, Fang R, Chou LC, Lowe AW, Sibley E. PDX1 regulation of FABP1 and novel target genes in human intestinal epithelial Caco-2 cells. Biochem Biophys Res Commun 2012; 423:183-7. [PMID: 22640736 DOI: 10.1016/j.bbrc.2012.05.113] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 05/18/2012] [Indexed: 10/28/2022]
Abstract
The transcription factor pancreatic and duodenal homeobox 1 (PDX1) plays an essential role in pancreatic development and in maintaining proper islet function via target gene regulation. Few intestinal PDX1 targets, however, have been described. We sought to define novel PDX1-regulated intestinal genes. Caco-2 human intestinal epithelial cells were engineered to overexpress PDX1 and gene expression profiles relative to control cells were assessed. Expression of 80 genes significantly increased while that of 49 genes significantly decreased more than 4-fold following PDX1 overexpression in differentiated Caco-2 cells. Analysis of the differentially regulated genes with known functional annotations revealed genes encoding transcription factors, growth factors, kinases, digestive glycosidases, nutrient transporters, nutrient binding proteins, and structural components. The gene for fatty acid binding protein 1, liver, FABP1, is repressed by PDX1 in Caco-2 cells. PDX1 overexpression in Caco-2 cells also results in repression of promoter activity driven by the 0.6kb FABP1 promoter. PDX1 regulation of promoter activity is consistent with the decrease in FABP1 RNA abundance resulting from PDX1 overexpression and identifies FABP1 as a candidate PDX1 target. PDX1 repression of FABP1, LCT, and SI suggests a role for PDX1 in patterning anterior intestinal development.
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Affiliation(s)
- Chin Chen
- Division of Pediatric Gastroenterology, Stanford University School of Medicine, Stanford, CA 94305-5208, United States
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Khoo C, Yang J, Weinrott SA, Kaestner KH, Naji A, Schug J, Stoffers DA. Research resource: the pdx1 cistrome of pancreatic islets. Mol Endocrinol 2012; 26:521-33. [PMID: 22322596 DOI: 10.1210/me.2011-1231] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The homeodomain transcription factor pancreas duodenal homeobox 1 (Pdx1, also known as insulin promoter factor 1) is a master regulator of pancreas development, as mice or humans lacking Pdx1 function are a pancreatic. Importantly, heterozygous mutations in Pdx1 cause early and late onset forms of diabetes in humans. Despite these central roles in development and adult β-cell function, we have only rudimentary knowledge of the transcriptome targets of Pdx1 that mediate these phenotypes. Therefore, we performed global location analysis of Pdx1 occupancy in pancreatic islets. We used evolutionary conservation of target genes to identify the most relevant Pdx1 targets by performing chromatin immunoprecipitation sequencing on both human and mouse islets. Remarkably, the conserved target set is highly enriched for genes annotated to function in endocrine system and metabolic disorders, various signaling pathways, and cell survival, providing a molecular explanation for many of the phenotypes resulting from Pdx1 deficiency.
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Affiliation(s)
- Cynthia Khoo
- Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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Abstract
Pancreas oganogenesis comprises a coordinated and highly complex interplay of signaling events and transcriptional networks that guide a step-wise process of organ development from early bud specification all the way to the final mature organ state. Extensive research on pancreas development over the last few years, largely driven by a translational potential for pancreatic diseases (diabetes, pancreatic cancer, and so on), is markedly advancing our knowledge of these processes. It is a tenable goal that we will one day have a clear, complete picture of the transcriptional and signaling codes that control the entire organogenetic process, allowing us to apply this knowledge in a therapeutic context, by generating replacement cells in vitro, or perhaps one day to the whole organ in vivo. This review summarizes findings in the past 5 years that we feel are amongst the most significant in contributing to the deeper understanding of pancreas development. Rather than try to cover all aspects comprehensively, we have chosen to highlight interesting new concepts, and to discuss provocatively some of the more controversial findings or proposals. At the end of the review, we include a perspective section on how the whole pancreas differentiation process might be able to be unwound in a regulated fashion, or redirected, and suggest linkages to the possible reprogramming of other pancreatic cell-types in vivo, and to the optimization of the forward-directed-differentiation of human embryonic stem cells (hESC), or induced pluripotential cells (iPSC), towards mature β-cells.
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Gao P, Jiao Y, Xiong Q, Wang CY, Gerling I, Gu W. Genetic and Molecular Basis of QTL of Diabetes in Mouse: Genes and Polymorphisms. Curr Genomics 2011; 9:324-37. [PMID: 19471607 PMCID: PMC2685644 DOI: 10.2174/138920208785133253] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2008] [Revised: 04/14/2008] [Accepted: 04/17/2008] [Indexed: 12/14/2022] Open
Abstract
A systematic study has been conducted of all available reports in PubMed and OMIM (Online Mendelian Inheritance in Man) to examine the genetic and molecular basis of quantitative genetic loci (QTL) of diabetes with the main focus on genes and polymorphisms. The major question is, What can the QTL tell us? Specifically, we want to know whether those genome regions differ from other regions in terms of genes relevant to diabetes. Which genes are within those QTL regions, and, among them, which genes have already been linked to diabetes? whether more polymorphisms have been associated with diabetes in the QTL regions than in the non-QTL regions. Our search revealed a total of 9038 genes from 26 type 1 diabetes QTL, which cover 667,096,006 bp of the mouse genomic sequence. On one hand, a large number of candidate genes are in each of these QTL; on the other hand, we found that some obvious candidate genes of QTL have not yet been investigated. Thus, the comprehensive search of candidate genes for known QTL may provide unexpected benefit for identifying QTL genes for diabetes.
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Affiliation(s)
- Peng Gao
- Departments of Orthopaedic Surgery, Campbell Clinic and Pathology, University of Tennessee Health Science Center, Memphis, Tennessee, USA
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Capellini TD, Zappavigna V, Selleri L. Pbx homeodomain proteins: TALEnted regulators of limb patterning and outgrowth. Dev Dyn 2011; 240:1063-86. [PMID: 21416555 DOI: 10.1002/dvdy.22605] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/13/2011] [Indexed: 12/14/2022] Open
Abstract
Limb development has long provided an excellent model for understanding the genetic principles driving embryogenesis. Studies utilizing chick and mouse have led to new insights into limb patterning and morphogenesis. Recent research has centered on the regulatory networks underlying limb development. Here, we discuss the hierarchical, overlapping, and iterative roles of Pbx family members in appendicular development that have emerged from genetic analyses in the mouse. Pbx genes are essential in determining limb bud positioning, early bud formation, limb axes establishment and coordination, and patterning and morphogenesis of most elements of the limb and girdle. Pbx proteins directly regulate critical effectors of limb and girdle development, including morphogen-encoding genes like Shh in limb posterior mesoderm, and transcription factor-encoding genes like Alx1 in pre-scapular domains. Interestingly, at least in limb buds, Pbx appear to act not only as Hox cofactors, but also in the upstream control of 5' HoxA/D gene expression.
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Affiliation(s)
- Terence D Capellini
- Department of Cell and Developmental Biology, Weill Medical College of Cornell University, New York, New York, USA
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33
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Adkins DE, Åberg K, McClay JL, Bukszár J, Zhao Z, Jia P, Stroup TS, Perkins D, McEvoy JP, Lieberman JA, Sullivan PF, van den Oord EJ. Genomewide pharmacogenomic study of metabolic side effects to antipsychotic drugs. Mol Psychiatry 2011; 16:321-32. [PMID: 20195266 PMCID: PMC2891163 DOI: 10.1038/mp.2010.14] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Understanding individual differences in the susceptibility to metabolic side effects as a response to antipsychotic therapy is essential to optimize the treatment of schizophrenia. Here, we perform genomewide association studies (GWAS) to search for genetic variation affecting the susceptibility to metabolic side effects. The analysis sample consisted of 738 schizophrenia patients, successfully genotyped for 492K single nucleotide polymorphisms (SNPs), from the genomic subsample of the Clinical Antipsychotic Trial of Intervention Effectiveness study. Outcomes included 12 indicators of metabolic side effects, quantifying antipsychotic-induced change in weight, blood lipids, glucose and hemoglobin A1c, blood pressure and heart rate. Our criterion for genomewide significance was a pre-specified threshold that ensures, on average, only 10% of the significant findings are false discoveries. A total of 21 SNPs satisfied this criterion. The top finding indicated that a SNP in Meis homeobox 2 (MEIS2) mediated the effects of risperidone on hip circumference (q=0.004). The same SNP was also found to mediate risperidone's effect on waist circumference (q=0.055). Genomewide significant finding were also found for SNPs in PRKAR2B, GPR98, FHOD3, RNF144A, ASTN2, SOX5 and ATF7IP2, as well as in several intergenic markers. PRKAR2B and MEIS2 both have previous research indicating metabolic involvement, and PRKAR2B has previously been shown to mediate antipsychotic response. Although our findings require replication and functional validation, this study shows the potential of GWAS to discover genes and pathways that potentially mediate adverse effects of antipsychotic medication.
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Affiliation(s)
- Daniel E. Adkins
- Center for Biomarker Research and Personalized Medicine, School of Pharmacy, Medical College of Virginia of Virginia Commonwealth University, Richmond, VA, USA,Corresponding author ()
| | - Karolina Åberg
- Center for Biomarker Research and Personalized Medicine, School of Pharmacy, Medical College of Virginia of Virginia Commonwealth University, Richmond, VA, USA
| | - Joseph L. McClay
- Center for Biomarker Research and Personalized Medicine, School of Pharmacy, Medical College of Virginia of Virginia Commonwealth University, Richmond, VA, USA
| | - József Bukszár
- Center for Biomarker Research and Personalized Medicine, School of Pharmacy, Medical College of Virginia of Virginia Commonwealth University, Richmond, VA, USA
| | - Zhongming Zhao
- Departments of Biomedical Informatics, Psychiatry, and Cancer Biology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Peilin Jia
- Departments of Biomedical Informatics, Psychiatry, and Cancer Biology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - T. Scott Stroup
- Department of Psychiatry, University of North Carolina at Chapel Hill, NC, USA
| | - Diana Perkins
- Department of Psychiatry, University of North Carolina at Chapel Hill, NC, USA
| | | | | | - Patrick F. Sullivan
- Departments of Genetics, Psychiatry, & Epidemiology, University of North Carolina at Chapel Hill, NC, USA, Department of Medical Epidemiology & Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Edwin J.C.G. van den Oord
- Center for Biomarker Research and Personalized Medicine, School of Pharmacy, Medical College of Virginia of Virginia Commonwealth University, Richmond, VA, USA
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Stein R. Insulin Gene Transcription: Factors Involved in Cell Type–Specific and Glucose‐Regulated Expression in Islet β Cells are Also Essential During Pancreatic Development. Compr Physiol 2011. [DOI: 10.1002/cphy.cp070202] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Teoh PH, Shu-Chien AC, Chan WK. Pbx1 is essential for growth of zebrafish swim bladder. Dev Dyn 2010; 239:865-74. [PMID: 20108353 DOI: 10.1002/dvdy.22221] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
pbx1, a TALE (three-amino acid loop extension) homeodomain transcription factor, is involved in a diverse range of developmental processes. We examined the expression of pbx1 during zebrafish development by in situ hybridization. pbx1 transcripts could be detected in the central nervous system and pharyngeal arches from 24 hpf onwards. In the swim bladder anlage, pbx1 was detected as early as 28 hpf, making it the earliest known marker for this organ. Morpholino-mediated gene knockdown of pbx1 revealed that the swim bladder failed to inflate, with eventual lethality occurring by 8 dpf. The knockdown of pbx1 did not perturb the expression of prdc and foxA3, with both early swim bladder markers appearing normally at 36 and 48 hpf, respectively. However, the expression of anxa5 was completely abolished by pbx1 knockdown at 60 hpf suggesting that pbx1 may be required during the late stage of swim bladder development.
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Affiliation(s)
- Pick-Har Teoh
- School of Biological Sciences, Universiti Sains Malaysia, Penang, Malaysia
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36
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Liu SH, Patel S, Gingras MC, Nemunaitis J, Zhou G, Chen C, Li M, Fisher W, Gibbs R, Brunicardi FC. PDX-1: demonstration of oncogenic properties in pancreatic cancer. Cancer 2010; 117:723-33. [PMID: 20886630 DOI: 10.1002/cncr.25629] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Accepted: 08/06/2010] [Indexed: 01/13/2023]
Abstract
BACKGROUND Pancreatic-duodenal homeobox 1 (PDX-1) is a transcription factor that regulates embryologic pancreas development and insulin expression in the adult islet; however, it is overexpressed in many types of cancer, including pancreatic cancer. The purpose of this study was to investigate the role of PDX-1 in tumorigenesis in human cells. METHODS In vitro cell proliferation, invasion, and transformation were performed in human embryonic kidney cell line (HEK 293), pancreatic cancer cell line MIA PaCa2, and human pancreatic ductal epithelial (HPDE) cells transiently or stably expressing PDX-1 or green fluorescent protein (GFP) PDX-1, with or without cotransfection of PDX-1 short hairpin RNA (shRNA). In vivo tumor formation was carried out in severe combined immunodeficiency (SCID) mice with subcutaneous injection of HEK 293 and MIA PaCa2 stably transfected cells. Cell cycle was analyzed by Western blot or immunostaining. Microarray of RNA from pancreatic adenocarcinoma cells with and without PDX-1 shRNA was performed and analyzed. RESULTS Transient and stable expressing PDX-1 significantly increased cell proliferation and invasion in HEK 293, human pancreatic ductal epithelial (HPDE), and MIA PaCa2 cells versus controls (P < .05), human PDX-1 shRNA reversed these effects. Expression of PDX-1 significantly increased colony formation in HEK 293, HPDE, and MIA PaCa2 cells versus controls in vitro (P < .05). PDX-1 promoted HEK 293 and MIA PaCa2 tumor formation in SCID mice as compared with that of control (P < .05). PDX-1 overexpression disrupted cell cycles proteins. PDX-1 expression was confirmed by Western blot and tracked by viewing of GFP-PDX-1 expression. Microarray data support an oncogenic role of PDX-1 in pancreas cancer cells. CONCLUSIONS PDX-1 induced increased cell proliferation, invasion, and colony formation in vitro, and resulted in markedly increased HEK 293 and MIA PaCa2 tumor formation in SCID mice. These data suggest that PDX-1 is a potential oncogene that regulates tumorigenesis.
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Affiliation(s)
- Shi-He Liu
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas, USA
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Hoffman BG, Robertson G, Zavaglia B, Beach M, Cullum R, Lee S, Soukhatcheva G, Li L, Wederell ED, Thiessen N, Bilenky M, Cezard T, Tam A, Kamoh B, Birol I, Dai D, Zhao Y, Hirst M, Verchere CB, Helgason CD, Marra MA, Jones SJM, Hoodless PA. Locus co-occupancy, nucleosome positioning, and H3K4me1 regulate the functionality of FOXA2-, HNF4A-, and PDX1-bound loci in islets and liver. Genome Res 2010; 20:1037-51. [PMID: 20551221 DOI: 10.1101/gr.104356.109] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The liver and pancreas share a common origin and coexpress several transcription factors. To gain insight into the transcriptional networks regulating the function of these tissues, we globally identify binding sites for FOXA2 in adult mouse islets and liver, PDX1 in islets, and HNF4A in liver. Because most eukaryotic transcription factors bind thousands of loci, many of which are thought to be inactive, methods that can discriminate functionally active binding events are essential for the interpretation of genome-wide transcription factor binding data. To develop such a method, we also generated genome-wide H3K4me1 and H3K4me3 localization data in these tissues. By analyzing our binding and histone methylation data in combination with comprehensive gene expression data, we show that H3K4me1 enrichment profiles discriminate transcription factor occupied loci into three classes: those that are functionally active, those that are poised for activation, and those that reflect pioneer-like transcription factor activity. Furthermore, we demonstrate that the regulated presence of H3K4me1-marked nucleosomes at transcription factor occupied promoters and enhancers controls their activity, implicating both tissue-specific transcription factor binding and nucleosome remodeling complex recruitment in determining tissue-specific gene expression. Finally, we apply these approaches to generate novel insights into how FOXA2, PDX1, and HNF4A cooperate to drive islet- and liver-specific gene expression.
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Affiliation(s)
- Brad G Hoffman
- Department of Cancer Endocrinology, British Columbia Cancer Agency, Vancouver, British Columbia V5Z 1L3, Canada.
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Galbo T, Pedersen IL, Fløyel T, Bang-Berthelsen CH, Serup P, Madsen OD, Hald J. Novel monoclonal antibodies against Pdx1 reveal feedback regulation of Pdx1 protein levels. Eur J Histochem 2010; 54:e19. [PMID: 20558340 PMCID: PMC3167305 DOI: 10.4081/ejh.2010.e19] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2010] [Revised: 02/26/2010] [Accepted: 02/26/2010] [Indexed: 11/23/2022] Open
Abstract
The aim of this study was to characterize two monoclonal antibodies (F6A11 and F109-D12) generated against Pdx1 (pancreatic and duodenal homeobox-1), a homeodomain transcription factor, which is critical for pancreas formation as well as for normal pancreatic beta cell function. For production of monoclonal antibodies, we immunized Robertsonian POSF (RBF)mice with a GST-Pdx1 fusion protein containing a 68-amino acid C-terminal fragment of rat Pdx1. These monoclonal antibodies detect Pdx1 by western blotting and allow immunohistochemical detection of Pdx1 in both mouse and rat tissue. F6A11 and F109-D12 produce IHC staining patterns indistinguishable from that obtained with highly specific polyclonal Pdx1 antisera raised in rabbits and goats, when applied to embryonic or adult mouse pancreatic tissue. In contrast to previously generated polyclonal anti-Pdx1 antisera, we also demonstrate that F6A11 works for intracellular fluorescence activated cell sorting (FACS) staining of Pdx1. By using F6A11, we characterize the induction of Pdx1 in the Doxycycline (DOX) inducible insulinoma cell line INSrαβ-Pdx1 and follow the reduction of Pdx1 after removing Dox. Finally, we show that induction of exogenous Pdx1 leads to a reduction in endogenous Pdx1 levels, which suggests that a negative feedback loop is involved in maintaining correct levels of Pdx1 in the cell.
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Affiliation(s)
- T Galbo
- Hagedorn Research Institute, Department of Beta-cell Regeneration, Gentofte, Denmark
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Chen C, Fang R, Davis C, Maravelias C, Sibley E. Pdx1 inactivation restricted to the intestinal epithelium in mice alters duodenal gene expression in enterocytes and enteroendocrine cells. Am J Physiol Gastrointest Liver Physiol 2009; 297:G1126-37. [PMID: 19808654 PMCID: PMC2850094 DOI: 10.1152/ajpgi.90586.2008] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Null mutant mice lacking the transcription factor pancreatic and duodenal homeobox 1 (Pdx1) are apancreatic and survive only a few days after birth. The role of Pdx1 in regulating intestinal gene expression has therefore yet to be determined in viable mice with normal pancreatic development. We hypothesized that conditional inactivation of Pdx1 restricted to the intestinal epithelium would alter intestinal gene expression and cell differentiation. Pdx1(flox/flox);VilCre mice with intestine-specific Pdx1 inactivation were generated by crossing a transgenic mouse strain expressing Cre recombinase, driven by a mouse villin 1 gene promoter fragment, with a mutant mouse strain homozygous for loxP site-flanked Pdx1. Pdx1 protein is undetectable in all epithelial cells in the intestinal epithelium of Pdx1(flox/flox);VilCre mice. Goblet cell number and mRNA abundance for mucin 3 and mucin 13 genes in the proximal small intestine are comparable between Pdx1(flox/flox);VilCre and control mice. Similarly, Paneth cell number and expression of Paneth cell-related genes Defa1, Defcr-rs1, and Mmp7 in the proximal small intestine remain statistically unchanged by Pdx1 inactivation. Although the number of enteroendocrine cells expressing chromogranin A/B, gastric inhibitory polypeptide (Gip), or somatostatin (Sst) is unaffected in the Pdx1(flox/flox);VilCre mice, mRNA abundance for Gip and Sst is significantly reduced in the proximal small intestine. Conditional Pdx1 inactivation attenuates intestinal alkaline phosphatase (IAP) activity in the duodenal epithelium, consistent with an average 91% decrease in expression of the mouse enterocyte IAP gene, alkaline phosphatase 3 (a novel Pdx1 target candidate), in the proximal small intestine following Pdx1 inactivation. We conclude that Pdx1 is necessary for patterning appropriate gene expression in enterocytes and enteroendocrine cells of the proximal small intestine.
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Affiliation(s)
- Chin Chen
- Stanford Univ. School of Medicine, CA 94305-5208, USA.
| | - Rixun Fang
- 1Division of Pediatric Gastroenterology and
| | - Corrine Davis
- 2Department of Comparative Medicine, Stanford University School of Medicine, Stanford, California
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Gidekel Friedlander SY, Chu GC, Snyder EL, Girnius N, Dibelius G, Crowley D, Vasile E, DePinho RA, Jacks T. Context-dependent transformation of adult pancreatic cells by oncogenic K-Ras. Cancer Cell 2009; 16:379-89. [PMID: 19878870 PMCID: PMC3048064 DOI: 10.1016/j.ccr.2009.09.027] [Citation(s) in RCA: 254] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2008] [Revised: 07/14/2009] [Accepted: 09/04/2009] [Indexed: 02/06/2023]
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal human malignancies. To investigate the cellular origin(s) of this cancer, we determined the effect of PDAC-relevant gene mutations in distinct cell types of the adult pancreas. We show that a subpopulation of Pdx1-expressing cells is susceptible to oncogenic K-Ras-induced transformation without tissue injury, whereas insulin-expressing endocrine cells are completely refractory to transformation under these conditions. However, chronic pancreatic injury can alter their endocrine fate and allow them to serve as the cell of origin for exocrine neoplasia. These results suggest that one mechanism by which inflammation and/or tissue damage can promote neoplasia is by altering the fate of differentiated cells that are normally refractory to oncogenic stimulation.
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Affiliation(s)
| | - Gerald C. Chu
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
- Department of Pathology, Brigham and Woman's Hospital, Boston, Massachusetts
- Center for Applied Cancer Science, Belfer Foundation Institute for Innovative Cancer Science
| | - Eric L. Snyder
- The David H. Koch Institute for Integrative Cancer Research at MIT, Cambridge, Massachusetts 02139, USA
- Department of Pathology, Brigham and Woman's Hospital, Boston, Massachusetts
| | - Nomeda Girnius
- The David H. Koch Institute for Integrative Cancer Research at MIT, Cambridge, Massachusetts 02139, USA
| | - Gregory Dibelius
- The David H. Koch Institute for Integrative Cancer Research at MIT, Cambridge, Massachusetts 02139, USA
| | - Denise Crowley
- The David H. Koch Institute for Integrative Cancer Research at MIT, Cambridge, Massachusetts 02139, USA
- Howard Hughes Medical Institute at Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Eliza Vasile
- The David H. Koch Institute for Integrative Cancer Research at MIT, Cambridge, Massachusetts 02139, USA
| | - Ronald A. DePinho
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
- Center for Applied Cancer Science, Belfer Foundation Institute for Innovative Cancer Science
- Department of Medicine and Genetics, Harvard Medical School, Boston, Massachusetts
| | - Tyler Jacks
- The David H. Koch Institute for Integrative Cancer Research at MIT, Cambridge, Massachusetts 02139, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- Howard Hughes Medical Institute at Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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Agoston Z, Schulte D. Meis2 competes with the Groucho co-repressor Tle4 for binding to Otx2 and specifies tectal fate without induction of a secondary midbrain-hindbrain boundary organizer. Development 2009; 136:3311-22. [DOI: 10.1242/dev.037770] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The transcription factor Otx2 is expressed throughout the anterior neuroectoderm and is required for the formation of all forebrain- and midbrain-derived structures. The molecular determinants that cooperate with Otx2 to subdivide its expression domain into distinct functional units are, however, poorly understood at present. We show here that the TALE-homeodomain protein Meis2 is expressed in the chick tectal anlage and is both necessary and sufficient for tectal development. Unlike known tectum-inducing genes, the ability of Meis2 to initiate tectal development does not involve the formation of a secondary midbrain-hindbrain boundary organizer, but instead requires direct interaction with Otx2. Using an Otx2-dependent reporter assay we demonstrate that Meis2 competes with the Groucho co-repressor Tle4 (Grg4) for binding to Otx2 and thereby restores Otx2 transcriptional activator function. Together, our data suggest a model in which the balance between a co-repressor and a co-activator, which compete for binding to Otx2 in the mesencephalic vesicle, provides spatial and temporal control over tectal development. Controlled formation of Meis2-containing higher order protein complexes might thus serve as a general mechanism to achieve subdivision of the anterior neuroectoderm into distinct functional units during embryogenesis.
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Affiliation(s)
- Zsuzsa Agoston
- Department of Neuroanatomy, Max-Planck Institute for Brain Research,Deutschordenstr. 46, Frankfurt, Germany
| | - Dorothea Schulte
- Department of Neuroanatomy, Max-Planck Institute for Brain Research,Deutschordenstr. 46, Frankfurt, Germany
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Jiang Y, Shi H, Liu J. Two Hox cofactors, the Meis/Hth homolog UNC-62 and the Pbx/Exd homolog CEH-20, function together during C. elegans postembryonic mesodermal development. Dev Biol 2009; 334:535-46. [PMID: 19643105 DOI: 10.1016/j.ydbio.2009.07.034] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2009] [Revised: 07/14/2009] [Accepted: 07/20/2009] [Indexed: 01/12/2023]
Abstract
The TALE homeodomain-containing PBC and MEIS proteins play multiple roles during metazoan development. Mutations in these proteins can cause various disorders, including cancer. In this study, we examined the roles of MEIS proteins in mesoderm development in C. elegans using the postembryonic mesodermal M lineage as a model system. We found that the MEIS protein UNC-62 plays essential roles in regulating cell fate specification and differentiation in the M lineage. Furthermore, UNC-62 appears to function together with the PBC protein CEH-20 in regulating these processes. Both unc-62 and ceh-20 have overlapping expression patterns within and outside of the M lineage, and they share physical and regulatory interactions. In particular, we found that ceh-20 is genetically required for the promoter activity of unc-62, providing evidence for another layer of regulatory interactions between MEIS and PBC proteins.
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Affiliation(s)
- Yuan Jiang
- Department of Molecular Biology and Genetics, Cornell University, 439 Biotechnology Building, Ithaca, NY 14853, USA
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Miyatsuka T, Matsuoka TA, Kaneto H. Transcription factors as therapeutic targets for diabetes. Expert Opin Ther Targets 2009; 12:1431-42. [PMID: 18851698 DOI: 10.1517/14728222.12.11.1431] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Islet cell implantation and pancreas transplantation have been used as treatments for diabetes but are limited by the shortage of donors and the requirement for lifelong immunosuppression. As an alternative, the generation of surrogate insulin-producing cells has been an area of interest for many researchers. Understanding how pancreatic beta-cells are generated during pancreas development will provide information that can be applied to generating surrogate beta-cells. OBJECTIVE To outline the current knowledge of pancreas development and differentiation, with a focus on the regulatory network of pancreas-enriched transcription factors and their targets. METHODS A review of relevant literature. CONCLUSIONS Pancreatic and duodenal homeobox 1 (Pdx1), Neurogenin 3 (Ngn3), and musculoaponeurotic fibrosarcoma oncogene homolog A (MafA) have been shown to play essential roles in pancreas development and beta-cell differentiation, and gain-of-function approaches indicate the potency of these factors for inducing differentiation of non-beta-cells into insulin-producing cells, which could lead to a novel therapy to cure diabetes.
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Affiliation(s)
- Takeshi Miyatsuka
- Osaka University Graduate School of Medicine, Department of Internal Medicine and Therapeutics, 2-2 Yamadaoka, Suita 565-0871, Osaka, Japan
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Gittes GK. Developmental biology of the pancreas: a comprehensive review. Dev Biol 2008; 326:4-35. [PMID: 19013144 DOI: 10.1016/j.ydbio.2008.10.024] [Citation(s) in RCA: 300] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2008] [Revised: 10/09/2008] [Accepted: 10/13/2008] [Indexed: 02/06/2023]
Abstract
Pancreatic development represents a fascinating process in which two morphologically distinct tissue types must derive from one simple epithelium. These two tissue types, exocrine (including acinar cells, centro-acinar cells, and ducts) and endocrine cells serve disparate functions, and have entirely different morphology. In addition, the endocrine tissue must become disconnected from the epithelial lining during its development. The pancreatic development field has exploded in recent years, and numerous published reviews have dealt specifically with only recent findings, or specifically with certain aspects of pancreatic development. Here I wish to present a more comprehensive review of all aspects of pancreatic development, though still there is not a room for discussion of stem cell differentiation to pancreas, nor for discussion of post-natal regeneration phenomena, two important fields closely related to pancreatic development.
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Affiliation(s)
- George K Gittes
- Children's Hospital of Pittsburgh and the University of Pittsburgh School of Medicine, Department of Pediatric Surgery, 3705 Fifth Avenue, Pittsburgh, PA 15213, USA
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Abstract
The major forms of diabetes are characterized by pancreatic islet beta-cell dysfunction and decreased beta-cell numbers, raising hope for cell replacement therapy. Although human islet transplantation is a cell-based therapy under clinical investigation for the treatment of type 1 diabetes, the limited availability of human cadaveric islets for transplantation will preclude its widespread therapeutic application. The result has been an intense focus on the development of alternate sources of beta cells, such as through the guided differentiation of stem or precursor cell populations or the transdifferentiation of more plentiful mature cell populations. Realizing the potential for cell-based therapies, however, requires a thorough understanding of pancreas development and beta-cell formation. Pancreas development is coordinated by a complex interplay of signaling pathways and transcription factors that determine early pancreatic specification as well as the later differentiation of exocrine and endocrine lineages. This review describes the current knowledge of these factors as they relate specifically to the emergence of endocrine beta cells from pancreatic endoderm. Current therapeutic efforts to generate insulin-producing beta-like cells from embryonic stem cells have already capitalized on recent advances in our understanding of the embryonic signals and transcription factors that dictate lineage specification and will most certainly be further enhanced by a continuing emphasis on the identification of novel factors and regulatory relationships.
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Affiliation(s)
- Jennifer M. Oliver-Krasinski
- Institute for Diabetes, Obesity and Metabolism and the Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA
| | - Doris A. Stoffers
- Institute for Diabetes, Obesity and Metabolism and the Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA
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Delporte FM, Pasque V, Devos N, Manfroid I, Voz ML, Motte P, Biemar F, Martial JA, Peers B. Expression of zebrafish pax6b in pancreas is regulated by two enhancers containing highly conserved cis-elements bound by PDX1, PBX and PREP factors. BMC DEVELOPMENTAL BIOLOGY 2008; 8:53. [PMID: 18485195 PMCID: PMC2409314 DOI: 10.1186/1471-213x-8-53] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2008] [Accepted: 05/16/2008] [Indexed: 02/04/2023]
Abstract
Background PAX6 is a transcription factor playing a crucial role in the development of the eye and in the differentiation of the pancreatic endocrine cells as well as of enteroendocrine cells. Studies on the mouse Pax6 gene have shown that sequences upstream from the P0 promoter are required for expression in the lens and the pancreas; but there remain discrepancies regarding the precise location of the pancreatic regulatory elements. Results Due to genome duplication in the evolution of ray-finned fishes, zebrafish has two pax6 genes, pax6a and pax6b. While both zebrafish pax6 genes are expressed in the developing eye and nervous system, only pax6b is expressed in the endocrine cells of the pancreas. To investigate the cause of this differential expression, we used a combination of in silico, in vivo and in vitro approaches. We show that the pax6b P0 promoter targets expression to endocrine pancreatic cells and also to enteroendocrine cells, retinal neurons and the telencephalon of transgenic zebrafish. Deletion analyses indicate that strong pancreatic expression of the pax6b gene relies on the combined action of two conserved regulatory enhancers, called regions A and C. By means of gel shift assays, we detected binding of the homeoproteins PDX1, PBX and PREP to several cis-elements of these regions. In constrast, regions A and C of the zebrafish pax6a gene are not active in the pancreas, this difference being attributable to sequence divergences within two cis-elements binding the pancreatic homeoprotein PDX1. Conclusion Our data indicate a conserved role of enhancers A and C in the pancreatic expression of pax6b and emphasize the importance of the homeoproteins PBX and PREP cooperating with PDX1, in activating pax6b expression in endocrine pancreatic cells. This study also provides a striking example of how adaptative evolution of gene regulatory sequences upon gene duplication progressively leads to subfunctionalization of the paralogous gene pair.
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Affiliation(s)
- François M Delporte
- Unit of Molecular Biology and Genetic Engineering, University of Liège, Giga-R, B34, Avenue de l'hôpital, 1, B-4000 Liège, Belgium.
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Rovira M, Jané-Valbuena J, Marchand M, Savatier P, Real FX, Skoudy A. Viral-mediated coexpression of Pdx1 and p48 regulates exocrine pancreatic differentiation in mouse ES cells. CLONING AND STEM CELLS 2008; 9:327-38. [PMID: 17907943 DOI: 10.1089/clo.2006.0064] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Embryonic stem cells (ES) can spontaneously activate a pancreatic differentiation program in vitro, although with low efficiency. The aim was to improve such process by using viral mediated gene transduction. In this study, we have examined the suitability of using viral vectors to express key transcriptional factors involved in pancreatic development. ES cell lines that constitutively express Pdx1, a homeodomain protein involved in both exocrine and endocrine pancreatic development and differentiation, were established using a lentiviral vector. These cells were additionally infected with an adenovirus expressing p48, a bHLH factor that is also crucial for pancreatic development and acinar differentiation. Quantitative RT-PCR analysis demonstrated an increase in the expression of exocrine genes, including those coding for both digestive enzymes and transcription factors. Immunocytochemical staining also revealed an increase in the number of amylase-expressing cell clusters. However, other important genes involved in acinar cell maturation (i.e., Mist1) were not modulated under these conditions, suggesting that the cells display features of immature exocrine cells or because of an uncoupled gene expression of the exocrine differentiation program. Importantly, this effect was selective for the acinar lineage as the expression of a large set of endocrine markers remained unchanged. Therefore, combined expression of key genes involved in pancreatic development may be a promising approach to generate mature pancreatic exocrine cells.
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Affiliation(s)
- Meritxell Rovira
- Cell and Molecular Biology Unit, Institut Municipal d'Investigació Mèdica (IMIM), Dr Aiguader 88, Barcelona, Spain
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Duesing K, Charpentier G, Marre M, Tichet J, Hercberg S, Balkau B, Froguel P, Gibson F. Evaluating the association of common PBX1 variants with type 2 diabetes. BMC MEDICAL GENETICS 2008; 9:14. [PMID: 18312624 PMCID: PMC2292156 DOI: 10.1186/1471-2350-9-14] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2007] [Accepted: 02/29/2008] [Indexed: 01/14/2023]
Abstract
BACKGROUND PBX1 is a biological candidate gene for type 2 diabetes at the 1q21-q24 susceptibility locus. The aim of this study was to evaluate the association of common PBX1 variants with type 2 diabetes in French Caucasian subjects. METHODS Employing a case-control design, we genotyped 39 SNPs spanning the PBX1 locus in 3,093 subjects to test for association with type 2 diabetes. RESULTS Several PBX1 SNPs, including the G21S coding SNP rs2275558, were nominally associated with type 2 diabetes but the strongest result was obtained with the intron 2 SNP rs2792248 (P = 0.004, OR 1.20 [95% CI 1.06-1.37]). The SNPSpD multiple testing correction method gave a significance threshold of P = 0.002 for the 39 SNPs genotyped, indicating that the rs2792248 association did not survive multiple testing adjustment. SNP rs2792248 did not show evidence of association with the French 1q linkage signal (P = 0.31; weighted NPL score 2.16). None of the PBX1 SNPs nominally associated with type 2 diabetes were associated with a range of quantitative metabolic traits in the normoglycemic control subjects CONCLUSION The available data does not support a major influence of common PBX1 variants on type 2 diabetes susceptibility or quantitative metabolic traits. In order to make progress in identifying the elusive susceptibility variants in the 1q region it will be necessary to carry out further large association studies, meta-analyses of existing data from individual studies, and deep resequencing of the 1q region.
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Affiliation(s)
- Konsta Duesing
- Genomic Medicine, Imperial College London, Hammersmith Campus, Du Cane Rd, London W12 0NN, UK
| | | | - Michel Marre
- Endocrinology-Diabetology, Bichat Hospital, Paris, France
- INSERM U695, Paris, France
| | - Jean Tichet
- Institut Régional Pour la Santé, Tours, France
| | - Serge Hercberg
- U557 Inserm/U1125 Inra/Cnam/University Paris 13, CRNH IdF, F-93017 Bobigny, France
| | - Beverley Balkau
- INSERM U780-IFR69, Villejuif, France
- Paris Univ-Sud, Orsay, France
| | - Philippe Froguel
- Genomic Medicine, Imperial College London, Hammersmith Campus, Du Cane Rd, London W12 0NN, UK
- CNRS 8090, Institut de Biologie de Lille, Institut Pasteur, Lille, France
| | - Fernando Gibson
- Genomic Medicine, Imperial College London, Hammersmith Campus, Du Cane Rd, London W12 0NN, UK
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Dong Y, Matigian N, Harvey TJ, Samaratunga H, Hooper JD, Clements JA. Tissue-specific promoter utilisation of the kallikrein-related peptidase genes, KLK5 and KLK7, and cellular localisation of the encoded proteins suggest roles in exocrine pancreatic function. Biol Chem 2008; 389:99-109. [DOI: 10.1515/bc.2008.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractTissue kallikrein (kallikrein 1) was first identified in pancreas and is the namesake of the kallikrein-related peptidase (KLK) family. KLK1 and the other 14 members of the human KLK family are encoded by 15 serine protease genes clustered at chromosome 19q13.4. Our Northern blot analysis of 19 normal human tissues for expression ofKLK4toKLK15identified pancreas as a common expression site for the gene cluster spanningKLK5toKLK13, as well as forKLK15which is located adjacent toKLK1. Consistent with previous reports detailing the ability ofKLKgenes to generate organ- and disease-specific transcripts, detailed molecular andin silicoanalyses indicated thatKLK5andKLK7generate transcripts in pancreas variant from those in skin or ovary. Consistently, we identified in the promoters of theseKLKgenes motifs which conform with consensus binding sites for transcription factors conferring pancreatic expression. In addition, immunohistochemical analysis revealed predominant localisation of KLK5 and KLK7 in acinar cells of the exocrine pancreas, suggesting roles for these enzymes in digestion. Our data also support expression patterns derived from gene duplication events in the humanKLKcluster. These findings suggest that, in addition to KLK1, other related KLK enzymes will function in the exocrine pancreas.
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Bumsted-O'Brien KM, Hendrickson A, Haverkamp S, Ashery-Padan R, Schulte D. Expression of the homeodomain transcription factor Meis2 in the embryonic and postnatal retina. J Comp Neurol 2008; 505:58-72. [PMID: 17729288 DOI: 10.1002/cne.21458] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Members of the Meis subfamily of homeodomain-containing transcription factors play important roles during development and disease. Here we report that the Meis family protein Meis2 is expressed by a subpopulation of gamma-aminobutyric acid (GABA)ergic amacrine (AM) cells in the adult and embryonic retina of different vertebrate species. In mice, Meis2-expressing (Meis2+) AM cells are not cholinergic or dopaminergic, but some are immunoreactive for neuronal nitric oxide synthase (bNOS). About 50% of the mouse Meis2+ AM cell population expresses the calcium-binding protein calretinin, and some Meis2+ AM cells show characteristics of Type II CD-15+ cells. AM cell expression of Meis2 is lost in a conditional knockout mouse model for Pax6, indicating a dependency upon Pax6. Bromodeoxyuridine pulse labeling experiments and immunohistochemical staining for the neuronal marker NeuN in embryonic mouse retinae indicate that Meis2 is an early marker for newly postmitotic AM cells. In addition, taking advantage of the protracted retinal development in humans, we show that newly generated AM cells express Meis2 before adopting the GABAergic or glycinergic neurotransmitter phenotype. As development proceeds, some AM cells lose Meis2 expression concomitantly with the appearance of glycine, while other AM cells retain Meis2 expression after they express GABA. These data identify Meis2 as a suitable marker for the study of AM cell diversity and development in addition to providing evidence for the stepwise specification of the glycinergic and GABAergic neurotransmitter phenotypes during AM cell differentiation.
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Affiliation(s)
- Keely M Bumsted-O'Brien
- Department of Neuroanatomy, Max-Planck-Institute for Brain Research, Deutschordenst. 46, 60218 Frankfurt, Germany
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