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Primate-specific stress-induced transcription factor POU2F1Z protects human neuronal cells from stress. Sci Rep 2021; 11:18808. [PMID: 34552146 PMCID: PMC8458439 DOI: 10.1038/s41598-021-98323-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Accepted: 08/30/2021] [Indexed: 12/14/2022] Open
Abstract
The emergence of new primate-specific genes is an essential factor in human and primate brain development and functioning. POU2F1/Oct-1 is a transcription regulator in higher eukaryotes which is involved in the regulation of development, differentiation, stress response, and other processes. We have demonstrated that the Tigger2 transposon insertion into the POU2F1 gene which occurred in the primate lineage led to the formation of an additional exon (designated the Z-exon). Z-exon-containing primate-specific Oct-1Z transcript includes a short upstream ORF (uORF) located at its 5’-end and the main ORF encoding the Oct-1Z protein isoform (Pou2F1 isoform 3, P14859-3), which differs from other Oct-1 isoforms by its N-terminal peptide. The Oct-1Z-encoding transcript is expressed mainly in human brain cortex. Under normal conditions, the translation of the ORF coding for the Oct-1Z isoform is repressed by uORF. Under various stress conditions, uORF enables a strong increase in the translation of the Oct-1Z-encoding ORF. Increased Oct-1Z expression levels in differentiating human neuroblasts activate genes controlling stress response, neural cell differentiation, brain formation, and organogenesis. We have shown that the Oct-1Z isoform of the POU2F1/Oct-1 transcription factor is an example of a primate-specific genomic element contributing to brain development and cellular stress defense.
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Javed A, Mattar P, Lu S, Kruczek K, Kloc M, Gonzalez-Cordero A, Bremner R, Ali RR, Cayouette M. Pou2f1 and Pou2f2 cooperate to control the timing of cone photoreceptor production in the developing mouse retina. Development 2020; 147:dev.188730. [DOI: 10.1242/dev.188730] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 08/19/2020] [Indexed: 12/27/2022]
Abstract
Multipotent retinal progenitor cells (RPCs) generate various cell types in a precise chronological order, but how exactly cone photoreceptor production is restricted to early stages remains unclear. Here, we show that the POU-homeodomain factors Pou2f1/Pou2f2, the homologs of Drosophila temporal identity factors nub/pdm2, regulate the timely production of cones in mice. Forcing sustained expression of Pou2f1 or Pou2f2 in RPCs expands the period of cone production, whereas misexpression in late-stage RPCs triggers ectopic cone production at the expense of late-born fates. Mechanistically, we report that Pou2f1 induces Pou2f2 expression, which binds to a POU motif in the promoter of the rod-inducing factor Nrl to repress its expression. Conversely, conditional inactivation of Pou2f2 in RPCs increases Nrl expression and reduces cone production. Finally, we provide evidence that Pou2f1 is part of a cross-regulatory cascade with the other temporal identity factors Ikzf1 and Casz1. These results uncover Pou2f1/2 as regulators of the temporal window for cone genesis and, given their widespread expression in the nervous system, raise the possibility of a general role in temporal patterning.
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Affiliation(s)
- Awais Javed
- Cellular Neurobiology Research Unit, Institut de recherches cliniques de Montreal (IRCM), Canada
- Molecular Biology Program, Université de Montréal, Canada
| | - Pierre Mattar
- Cellular Neurobiology Research Unit, Institut de recherches cliniques de Montreal (IRCM), Canada
| | - Suying Lu
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Canada. Department of Ophthalmology and Vision Science, Department of Lab Medicine and Pathobiology, University of Toronto
| | | | | | | | - Rod Bremner
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Canada. Department of Ophthalmology and Vision Science, Department of Lab Medicine and Pathobiology, University of Toronto
| | - Robin R. Ali
- UCL Institute of Ophthalmology, London, UK
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
| | - Michel Cayouette
- Cellular Neurobiology Research Unit, Institut de recherches cliniques de Montreal (IRCM), Canada
- Molecular Biology Program, Université de Montréal, Canada
- Department of Medicine, Université de Montréal, Canada
- Department of Anatomy and Cell Biology; Division of Experimental Medicine, McGill University, Canada
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Vázquez-Arreguín K, Bensard C, Schell JC, Swanson E, Chen X, Rutter J, Tantin D. Oct1/Pou2f1 is selectively required for colon regeneration and regulates colon malignancy. PLoS Genet 2019; 15:e1007687. [PMID: 31059499 PMCID: PMC6522070 DOI: 10.1371/journal.pgen.1007687] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 05/16/2019] [Accepted: 04/16/2019] [Indexed: 12/22/2022] Open
Abstract
The transcription factor Oct1/Pou2f1 promotes poised gene expression states, mitotic stability, glycolytic metabolism and other characteristics of stem cell potency. To determine the effect of Oct1 loss on stem cell maintenance and malignancy, we deleted Oct1 in two different mouse gut stem cell compartments. Oct1 deletion preserved homeostasis in vivo and the ability to establish organoids in vitro, but blocked the ability to recover from treatment with dextran sodium sulfate, and the ability to maintain organoids after passage. In a chemical model of colon cancer, loss of Oct1 in the colon severely restricted tumorigenicity. In contrast, loss of one or both Oct1 alleles progressively increased tumor burden in a colon cancer model driven by loss-of-heterozygosity of the tumor suppressor gene Apc. The different outcomes are consistent with prior findings that Oct1 promotes mitotic stability, and consistent with differentially expressed genes between the two models. Oct1 ChIPseq using HCT116 colon carcinoma cells identifies target genes associated with mitotic stability, metabolism, stress response and malignancy. This set of gene targets overlaps significantly with genes differentially expressed in the two tumor models. These results reveal that Oct1 is selectively required for recovery after colon damage, and that Oct1 has potent effects in colon malignancy, with outcome (pro-oncogenic or tumor suppressive) dictated by tumor etiology. Colorectal cancer is the second leading cause of cancer death in the United States. Approximately 35% of diagnosed patients eventually succumb to disease. The high incidence and mortality due to colon cancer demand a better understanding of factors controlling the physiology and pathophysiology of the gastrointestinal tract. Previously, we and others showed that the widely expressed transcription factor Oct1 is expressed at higher protein levels in stem cells, including intestinal stem cells. Here we use deletion of a conditional mouse Oct1 (Pou2f1) allele in two different intestinal stem cell compartments to study gut homeostasis. We then proceed to investigate the effect of Oct1 loss in colon regeneration and malignancy. The results indicate that Oct1 loss is dispensable for maintenance of the mouse gut, but required for recovery after damage to the colon epithelium. We also find that Oct1 loss has opposing effects in two different mouse colon cancer models, and further that the two models are associated with different gene expression signatures. The differentially expressed genes are enriched for Oct1 targets, suggesting that differential gene control by Oct1 is one mechanism underlying the different outcomes.
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Affiliation(s)
- Karina Vázquez-Arreguín
- Department of Pathology and Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT, United States of America
| | - Claire Bensard
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, United States of America
| | - John C. Schell
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, United States of America
| | - Eric Swanson
- Department of Pathology and Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT, United States of America
| | - Xinjian Chen
- Department of Pathology and Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT, United States of America
| | - Jared Rutter
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, United States of America
- Howard Hughes Medical Institute, Salt Lake City, Utah, United States of America
| | - Dean Tantin
- Department of Pathology and Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT, United States of America
- * E-mail:
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Cao Y. Tumorigenesis as a process of gradual loss of original cell identity and gain of properties of neural precursor/progenitor cells. Cell Biosci 2017; 7:61. [PMID: 29177029 PMCID: PMC5693707 DOI: 10.1186/s13578-017-0188-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 10/27/2017] [Indexed: 02/07/2023] Open
Abstract
Cancer is a complex disease without a unified explanation for its cause so far. Our recent work demonstrates that cancer cells share similar regulatory networks and characteristics with embryonic neural cells. Based on the study, I will address the relationship between tumor and neural cells in more details. I collected the evidence from various aspects of cancer development in many other studies, and integrated the information from studies on cancer cell properties, cell fate specification during embryonic development and evolution. Synthesis of the information strongly supports that cancer cells share much more similarities with neural progenitor/stem cells than with mesenchymal-type cells and that tumorigenesis represents a process of gradual loss of cell or lineage identity and gain of characteristics of neural cells. I also discuss cancer EMT, a concept having been under intense debate, and possibly the true meaning of EMT in cancer initiation and development. This synthesis provides fresh insights into a unified explanation for and a previously unrecognized nature of tumorigenesis, which might not be revealed by studies on individual molecular events. The review will also present some brief suggestions for cancer research based on the proposed model of tumorigenesis.
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Affiliation(s)
- Ying Cao
- Model Animal Research Center and MOE Key Laboratory of Model Animals for Disease Study, Nanjing University, 12 Xuefu Road, Pukou High-Tech Zone, Nanjing, 210061 China
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Manojlovic Z, Earwood R, Kato A, Perez D, Cabrera OA, Didier R, Megraw TL, Stefanovic B, Kato Y. La-related protein 6 controls ciliated cell differentiation. Cilia 2017; 6:4. [PMID: 28344782 PMCID: PMC5364628 DOI: 10.1186/s13630-017-0047-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2016] [Accepted: 02/16/2017] [Indexed: 01/07/2023] Open
Abstract
Background La-related protein 6 (LARP6) is an evolutionally conserved RNA-binding protein. Vertebrate LARP6 binds the 5′ stem-loop found in mRNAs encoding type I collagen to regulate their translation, but other target mRNAs and additional functions for LARP6 are unknown. The aim of this study was to elucidate an additional function of LARP6 and to evaluate the importance of its function during development. Methods To uncover the role of LARP6 in development, we utilized Morpholino Oligos to deplete LARP6 protein in Xenopus embryos. Then, embryonic phenotypes and ciliary structures of LAPR6 morphants were examined. To identify the molecular mechanism underlying ciliogenesis regulated by LARP6, we tested the expression level of cilia-related genes, which play important roles in ciliogenesis, by RT-PCR or whole mount in situ hybridization (WISH). Results We knocked down LARP6 in Xenopus embryos and found neural tube closure defects. LARP6 mutant, which compromises the collagen synthesis, could rescue these defects. Neural tube closure defects are coincident with lack of cilia, antenna-like cellular organelles with motility- or sensory-related functions, in the neural tube. The absence of cilia at the epidermis was also observed in LARP6 morphants, and this defect was due to the absence of basal bodies which are formed from centrioles and required for ciliary assembly. In the process of multi-ciliated cell (MCC) differentiation, mcidas, which activates the transcription of genes required for centriole formation during ciliogenesis, could partially restore MCCs in LARP6 morphants. In addition, LARP6 likely controls the expression of mcidas in a Notch-independent manner. Conclusions La-related protein 6 is involved in ciliated cell differentiation during development by controlling the expression of cilia-related genes including mcidas. This LARP6 function involves a mechanism that is distinct from its established role in binding to collagen mRNAs and regulating their translation. Electronic supplementary material The online version of this article (doi:10.1186/s13630-017-0047-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Zarko Manojlovic
- Department of Biomedical Sciences, Florida State University College of Medicine, 1115W. Call Street, Tallahassee, FL 32306-4300 USA.,Department of Translational Genomics, Keck School of Medicine of University of Southern California, Los Angeles, CA 90089-9601 USA
| | - Ryan Earwood
- Department of Biomedical Sciences, Florida State University College of Medicine, 1115W. Call Street, Tallahassee, FL 32306-4300 USA
| | - Akiko Kato
- Department of Biomedical Sciences, Florida State University College of Medicine, 1115W. Call Street, Tallahassee, FL 32306-4300 USA
| | - Diana Perez
- Department of Biomedical Sciences, Florida State University College of Medicine, 1115W. Call Street, Tallahassee, FL 32306-4300 USA
| | - Oscar A Cabrera
- Department of Biomedical Sciences, Florida State University College of Medicine, 1115W. Call Street, Tallahassee, FL 32306-4300 USA
| | - Ruth Didier
- Department of Biomedical Sciences, Florida State University College of Medicine, 1115W. Call Street, Tallahassee, FL 32306-4300 USA
| | - Timothy L Megraw
- Department of Biomedical Sciences, Florida State University College of Medicine, 1115W. Call Street, Tallahassee, FL 32306-4300 USA
| | - Branko Stefanovic
- Department of Biomedical Sciences, Florida State University College of Medicine, 1115W. Call Street, Tallahassee, FL 32306-4300 USA
| | - Yoichi Kato
- Department of Biomedical Sciences, Florida State University College of Medicine, 1115W. Call Street, Tallahassee, FL 32306-4300 USA
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Pankratova EV, Stepchenko AG, Portseva T, Mogila VA, Georgieva SG. Different N-terminal isoforms of Oct-1 control expression of distinct sets of genes and their high levels in Namalwa Burkitt's lymphoma cells affect a wide range of cellular processes. Nucleic Acids Res 2016; 44:9218-9230. [PMID: 27407111 PMCID: PMC5100579 DOI: 10.1093/nar/gkw623] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 06/28/2016] [Accepted: 07/01/2016] [Indexed: 01/03/2023] Open
Abstract
Oct-1 transcription factor has various functions in gene regulation. Its expression level is increased in several types of cancer and is associated with poor survival prognosis. Here we identified distinct Oct-1 protein isoforms in human cells and compared gene expression patterns and functions for Oct-1A, Oct-1L, and Oct-1X isoforms that differ by their N-terminal sequences. The longest isoform, Oct-1A, is abundantly expressed and is the main Oct-1 isoform in most of human tissues. The Oct-1L and the weakly expressed Oct-1X regulate the majority of Oct-1A targets as well as additional sets of genes. Oct-1X controls genes involved in DNA replication, DNA repair, RNA processing, and cellular response to stress. The high level of Oct-1 isoforms upregulates genes related to cell cycle progression and activates proliferation both in Namalwa Burkitt's lymphoma cells and primary human fibroblasts. It downregulates expression of genes related to antigen processing and presentation, cytokine-cytokine receptor interaction, oxidative metabolism, and cell adhesion, thus facilitating pro-oncogenic processes.
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Affiliation(s)
- Elizaveta V Pankratova
- Department of Transcription Factors, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov Str. 32, Moscow 119991 Russia
| | - Alexander G Stepchenko
- Department of Transcription Factors, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov Str. 32, Moscow 119991 Russia
| | - Tatiana Portseva
- Department of Transcription Factors, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov Str. 32, Moscow 119991 Russia
| | - Vladic A Mogila
- Department of Transcription Factors, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov Str. 32, Moscow 119991 Russia
| | - Sofia G Georgieva
- Department of Transcription Factors, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov Str. 32, Moscow 119991 Russia
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Gao J, Ruan H, Qi X, Tao Y, Guo X, Shen W. HDAC3 But not HDAC2 Mediates Visual Experience-Dependent Radial Glia Proliferation in the Developing Xenopus Tectum. Front Cell Neurosci 2016; 10:221. [PMID: 27729849 PMCID: PMC5037170 DOI: 10.3389/fncel.2016.00221] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Accepted: 09/09/2016] [Indexed: 01/12/2023] Open
Abstract
Radial glial cells (RGs) are one of the important progenitor cells that can differentiate into neurons or glia to form functional neural circuits in the developing central nervous system (CNS). Histone deacetylases (HDACs) has been associated with visual activity dependent changes in BrdU-positive progenitor cells in the developing brain. We previously have shown that HDAC1 is involved in the experience-dependent proliferation of RGs. However, it is less clear whether two other members of class I HDACs, HDAC2 and HDAC3, are involved in the regulation of radial glia proliferation. Here, we reported that HDAC2 and HDAC3 expression were developmentally regulated in tectal cells, especially in the ventricular layer of the BLBP-positive RGs. Pharmacological blockade using an inhibitor of class I HDACs, MS-275, decreased the number of BrdU-positive dividing progenitor cells. Specific knockdown of HDAC3 but not HDAC2 decreased the number of BrdU- and BLBP-labeled cells, suggesting that the proliferation of radial glia was selectively mediated by HDAC3. Visual deprivation induced selective augmentation of histone H4 acetylation at lysine 16 in BLBP-positive cells. Furthermore, the visual deprivation-induced increase in BrdU-positive cells was partially blocked by HDAC3 downregulation but not by HDAC2 knockdown at stage 49 tadpoles. These data revealed a specific role of HDAC3 in experience-dependent radial glia proliferation during the development of Xenopus tectum.
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Affiliation(s)
- Juanmei Gao
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University Hangzhou, Zhejiang, China
| | - Hangze Ruan
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University Hangzhou, Zhejiang, China
| | - Xianjie Qi
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University Hangzhou, Zhejiang, China
| | - Yi Tao
- Department of Neurosurgery, Nanjing Medical University and Jiangsu Cancer Hospital Nanjing, Jiangsu, China
| | - Xia Guo
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University Hangzhou, Zhejiang, China
| | - Wanhua Shen
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University Hangzhou, Zhejiang, China
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Chen C, Jin J, Lee GA, Silva E, Donoghue M. Cross-species functional analyses reveal shared and separate roles for Sox11 in frog primary neurogenesis and mouse cortical neuronal differentiation. Biol Open 2016; 5:409-17. [PMID: 26962049 PMCID: PMC4890661 DOI: 10.1242/bio.015404] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
A well-functioning brain requires production of the correct number and types of cells during development; cascades of transcription factors are essential for cellular coordination. Sox proteins are transcription factors that affect various processes in the development of the nervous system. Sox11, a member of the SoxC family, is expressed in differentiated neurons and supports neuronal differentiation in several systems. To understand how generalizable the actions of Sox11 are across phylogeny, its function in the development of the frog nervous system and the mouse cerebral cortex were compared. Expression of Sox11 is largely conserved between these species; in the developing frog, Sox11 is expressed in the neural plate, neural tube and throughout the segmented brain, while in the mouse cerebral cortex, Sox11 is expressed in differentiated zones, including the preplate, subplate, marginal zone and cortical plate. In both frog and mouse, data demonstrate that Sox11 supports a role in promoting neuronal differentiation, with Sox11-positive cells expressing pan-neural markers and becoming morphologically complex. However, frog and mouse Sox11 cannot substitute for one another; a functional difference likely reflected in sequence divergence. Thus, Sox11 appears to act similarly in subserving neuronal differentiation but is species-specific in frog neural development and mouse corticogenesis. Summary: Sox11 acts to designate neurons in both mouse and frog brains, but orthologs are not functionally redundant. These data show evolutionary conservation of Sox11 function with molecular divergence.
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Affiliation(s)
- Chao Chen
- Department of Biology, Georgetown University, 37th and O Street NW, Washington, DC 20057, USA
| | - Jing Jin
- Department of Biology, Georgetown University, 37th and O Street NW, Washington, DC 20057, USA
| | - Garrett A Lee
- Department of Biology, Georgetown University, 37th and O Street NW, Washington, DC 20057, USA
| | - Elena Silva
- Department of Biology, Georgetown University, 37th and O Street NW, Washington, DC 20057, USA
| | - Maria Donoghue
- Department of Biology, Georgetown University, 37th and O Street NW, Washington, DC 20057, USA
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Mashanov VS, Zueva OR, García-Arrarás JE. Heterogeneous generation of new cells in the adult echinoderm nervous system. Front Neuroanat 2015; 9:123. [PMID: 26441553 PMCID: PMC4585025 DOI: 10.3389/fnana.2015.00123] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 08/29/2015] [Indexed: 11/13/2022] Open
Abstract
Adult neurogenesis, generation of new functional cells in the mature central nervous system (CNS), has been documented in a number of diverse organisms, ranging from humans to invertebrates. However, the origin and evolution of this phenomenon is still poorly understood for many of the key phylogenetic groups. Echinoderms are one such phylum, positioned as a sister group to chordates within the monophyletic clade Deuterostomia. They are well known for the ability of their adult organs, including the CNS, to completely regenerate after injury. Nothing is known, however, about production of new cells in the nervous tissue under normal physiological conditions in these animals. In this study, we show that new cells are continuously generated in the mature radial nerve cord (RNC) of the sea cucumber Holothuria glaberrima. Importantly, this neurogenic activity is not evenly distributed, but is significantly more extensive in the lateral regions of the RNC than along the midline. Some of the new cells generated in the apical region of the ectoneural neuroepithelium leave their place of origin and migrate basally to populate the neural parenchyma. Gene expression analysis showed that generation of new cells in the adult sea cucumber CNS is associated with transcriptional activity of genes known to be involved in regulation of various aspects of neurogenesis in other animals. Further analysis of one of those genes, the transcription factor Myc, showed that it is expressed, in some, but not all radial glial cells, suggesting heterogeneity of this CNS progenitor cell population in echinoderms.
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Affiliation(s)
| | - Olga R Zueva
- Department of Biology, University of Puerto Rico Rio Piedras, PR, USA
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10
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Coumailleau P, Kah O. Expression of the cyp19a1 gene in the adult brain of Xenopus is neuronal and not sexually dimorphic. Gen Comp Endocrinol 2015; 221:203-12. [PMID: 26255686 DOI: 10.1016/j.ygcen.2015.08.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 07/16/2015] [Accepted: 08/04/2015] [Indexed: 01/07/2023]
Abstract
The last step of oestrogen biosynthesis is catalyzed by the enzyme aromatase, the product of the cyp19a1 gene. In vertebrates, cyp19a1 is expressed in the brain resulting in a local oestrogen production that seems important not only for the control of reproduction-related circuits and sexual behaviour, but also for the regulation of neural development, synaptic plasticity and cell survival. In adult amphibians, the precise sites of expression of cyp19a1 in the brain have not been investigated which prevents proper understanding of its potential physiological functions. The present study aimed at examining the precise neuroanatomical distribution of cyp19a1 transcripts in adult brains of both male and female Xenopus. We found that cyp19a1 expression is highly regionalized in the brains of both sexes. The highest expression was found in the anterior part of the preoptic area and in the caudal hypothalamus, but significant levels of cyp19a1 transcripts were also found in the supraoptic paraventricular and suprachiasmatic areas, and in brain regions corresponding to the septum, bed nucleus of the stria terminalis and amygdala. Importantly, no obvious difference between male and female Xenopus was detected at the level of cyp19a1 transcripts. Additionally, in the brain of adult Xenopus, cyp19a1 transcripts were detected in neurons, and not in glial cells. These data and those available in other vertebrates on cyp19a1/aromatase expression suggest that, with the intriguing exception of teleost fishes, cyp19a1 was under strong evolutionary conservation with respect to its sites of expression and the nature of the cells in which it is expressed.
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Affiliation(s)
- Pascal Coumailleau
- Research Institute in Health, Environment and Occupation, INSERM U1085, SFR Biosite, Université de Rennes 1, Campus de Beaulieu, 35 042 Rennes cedex, France.
| | - Olivier Kah
- Research Institute in Health, Environment and Occupation, INSERM U1085, SFR Biosite, Université de Rennes 1, Campus de Beaulieu, 35 042 Rennes cedex, France
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Tao Y, Ruan H, Guo X, Li L, Shen W. HDAC1 regulates the proliferation of radial glial cells in the developing Xenopus tectum. PLoS One 2015; 10:e0120118. [PMID: 25789466 PMCID: PMC4366096 DOI: 10.1371/journal.pone.0120118] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 02/04/2015] [Indexed: 12/01/2022] Open
Abstract
In the developing central nervous system (CNS), progenitor cells differentiate into progeny to form functional neural circuits. Radial glial cells (RGs) are a transient progenitor cell type that is present during neurogenesis. It is thought that a combination of neural trophic factors, neurotransmitters and electrical activity regulates the proliferation and differentiation of RGs. However, it is less clear how epigenetic modulation changes RG proliferation. We sought to explore the effect of histone deacetylase (HDAC) activity on the proliferation of RGs in the visual optic tectum of Xenopus laevis. We found that the number of BrdU-labeled precursor cells along the ventricular layer of the tectum decrease developmentally from stage 46 to stage 49. The co-labeling of BrdU-positive cells with brain lipid-binding protein (BLBP), a radial glia marker, showed that the majority of BrdU-labeled cells along the tectal midline are RGs. BLBP-positive cells are also developmentally decreased with the maturation of the brain. Furthermore, HDAC1 expression is developmentally down-regulated in tectal cells, especially in the ventricular layer of the tectum. Pharmacological blockade of HDACs using Trichostatin A (TSA) or Valproic acid (VPA) decreased the number of BrdU-positive, BLBP-positive and co-labeling cells. Specific knockdown of HDAC1 by a morpholino (HDAC1-MO) decreased the number of BrdU- and BLBP-labeled cells and increased the acetylation level of histone H4 at lysine 12 (H4K12). The visual deprivation-induced increase in BrdU- and BLBP-positive cells was blocked by HDAC1 knockdown at stage 49 tadpoles. These data demonstrate that HDAC1 regulates radial glia cell proliferation in the developing optical tectum of Xenopus laevis.
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Affiliation(s)
- Yi Tao
- Department of Neurosurgery, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu, 210029, China
| | - Hangze Ruan
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Xia Guo
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Lixin Li
- Department of Neurosurgery, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu, 210029, China
- * E-mail: (LL); (WS)
| | - Wanhua Shen
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, China
- * E-mail: (LL); (WS)
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Mashanov VS, Zueva OR, García-Arrarás JE. Expression of pluripotency factors in echinoderm regeneration. Cell Tissue Res 2014; 359:521-536. [PMID: 25468557 DOI: 10.1007/s00441-014-2040-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 10/16/2014] [Indexed: 12/15/2022]
Abstract
Cell dedifferentiation is an integral component of post-traumatic regeneration in echinoderms. As dedifferentiated cells become multipotent, we asked if this spontaneous broadening of developmental potential is associated with the action of the same pluripotency factors (known as Yamanaka factors) that were used to induce pluripotency in specialized mammalian cells. In this study, we investigate the expression of orthologs of the four Yamanaka factors in regeneration of two different organs, the radial nerve cord and the digestive tube, in the sea cucumber Holothuria glaberrima. All four pluripotency factors are expressed in uninjured animals, although their expression domains do not always overlap. In regeneration, the expression levels of the four genes were not regulated in a coordinated way, but instead showed different dynamics for individual genes and also were different between the radial nerve and the gut. SoxB1, the ortholog of the mammalian Sox2, was drastically downregulated in the regenerating intestine, suggesting that this factor is not required for dedifferentiation/regeneration in this organ. On the other hand, during the early post-injury stage, Myc, the sea cucumber ortholog of c-Myc, was significantly upregulated in both the intestine and the radial nerve cord and is therefore hypothesized to play a central role in dedifferentiation/regeneration of various tissue types.
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Affiliation(s)
- Vladimir S Mashanov
- Department of Biology, University of Puerto Rico, PO Box 70377, San Juan, PR, 00936-8377, USA.
| | - Olga R Zueva
- Department of Biology, University of Puerto Rico, PO Box 70377, San Juan, PR, 00936-8377, USA
| | - José E García-Arrarás
- Department of Biology, University of Puerto Rico, PO Box 70377, San Juan, PR, 00936-8377, USA
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13
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del Rosario RCH, Rayan NA, Prabhakar S. Noncoding origins of anthropoid traits and a new null model of transposon functionalization. Genome Res 2014; 24:1469-84. [PMID: 25043600 PMCID: PMC4158753 DOI: 10.1101/gr.168963.113] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Little is known about novel genetic elements that drove the emergence of anthropoid primates. We exploited the sequencing of the marmoset genome to identify 23,849 anthropoid-specific constrained (ASC) regions and confirmed their robust functional signatures. Of the ASC base pairs, 99.7% were noncoding, suggesting that novel anthropoid functional elements were overwhelmingly cis-regulatory. ASCs were highly enriched in loci associated with fetal brain development, motor coordination, neurotransmission, and vision, thus providing a large set of candidate elements for exploring the molecular basis of hallmark primate traits. We validated ASC192 as a primate-specific enhancer in proliferative zones of the developing brain. Unexpectedly, transposable elements (TEs) contributed to >56% of ASCs, and almost all TE families showed functional potential similar to that of nonrepetitive DNA. Three L1PA repeat-derived ASCs displayed coherent eye-enhancer function, thus demonstrating that the "gene-battery" model of TE functionalization applies to enhancers in vivo. Our study provides fundamental insights into genome evolution and the origins of anthropoid phenotypes and supports an elegantly simple new null model of TE exaptation.
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Affiliation(s)
- Ricardo C H del Rosario
- Computational and Systems Biology, Genome Institute of Singapore, #02-01 Genome, Singapore 138672
| | - Nirmala Arul Rayan
- Computational and Systems Biology, Genome Institute of Singapore, #02-01 Genome, Singapore 138672
| | - Shyam Prabhakar
- Computational and Systems Biology, Genome Institute of Singapore, #02-01 Genome, Singapore 138672
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14
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Coumailleau P, Kah O. Cyp19a1 (aromatase) expression in the Xenopus brain at different developmental stages. J Neuroendocrinol 2014; 26:226-36. [PMID: 24612124 PMCID: PMC4238815 DOI: 10.1111/jne.12142] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Revised: 02/17/2014] [Accepted: 02/22/2014] [Indexed: 12/24/2022]
Abstract
Cytochrome P450 aromatase (P450arom; aromatase) is a microsomal enzyme involved in the production of endogeneous sex steroids by converting testosterone into oestradiol. Aromatase is the product of the cyp19a1 gene and plays a crucial role in the sexual differentiation of the brain and in the regulation of reproductive functions. In the brain of mammals and birds, expression of cyp19a1 has been demonstrated in neuronal populations of the telencephalon and diencephalon. By contrast, a wealth of evidence established that, in teleost fishes, aromatase expression in the brain is restricted to radial glial cells. The present study investigated the precise neuroanatomical distribution of cyp19a1 mRNA during brain development in Xenopus laevis (late embryonic to juvenile stages). For this purpose, we used in situ hybridisation alone or combined with the detection of a proliferative (proliferating cell nuclear antigen), glial (brain lipid binding protein, Vimentin) or neuronal (acetylated tubulin; HuC/D; NeuroβTubulin) markers. We provide evidence that cyp19a1 expression in the brain is initiated from the very early larval stage and remains strongly detected until the juvenile and adult stages. At all stages analysed, we found the highest expression of cyp19a1 in the preoptic area and the hypothalamus compared to the rest of the brain. In these two brain regions, cyp19a1-positive cells were never detected in the ventricular layers. Indeed, no co-labelling could be observed with radial glial (brain lipid binding protein, Vimentin) or dividing progenitors (proliferating cell nuclear antigen) markers. By contrast, cyp19a1-positive cells perfectly matched with the distribution of post-mitotic neurones as shown by the use of specific markers (HuC/D, acetylated tubulin and NeuroβTubulin). These data suggest that, similar to that found in other tetrapods, aromatase in the brain of amphibians is found in post-mitotic neurones and not in radial glia as reported in teleosts.
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Affiliation(s)
- P Coumailleau
- Neuroendocrine Effects of Endocrine Disruptors, IRSET, INSERM U1085, SFR Biosit, Université de Rennes 1, Rennes, France
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15
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Rouault H, Santolini M, Schweisguth F, Hakim V. Imogene: identification of motifs and cis-regulatory modules underlying gene co-regulation. Nucleic Acids Res 2014; 42:6128-45. [PMID: 24682824 PMCID: PMC4041412 DOI: 10.1093/nar/gku209] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Cis-regulatory modules (CRMs) and motifs play a central role in tissue and condition-specific gene expression. Here we present Imogene, an ensemble of statistical tools that we have developed to facilitate their identification and implemented in a publicly available software. Starting from a small training set of mammalian or fly CRMs that drive similar gene expression profiles, Imogene determines de novocis-regulatory motifs that underlie this co-expression. It can then predict on a genome-wide scale other CRMs with a regulatory potential similar to the training set. Imogene bypasses the need of large datasets for statistical analyses by making central use of the information provided by the sequenced genomes of multiple species, based on the developed statistical tools and explicit models for transcription factor binding site evolution. We test Imogene on characterized tissue-specific mouse developmental CRMs. Its ability to identify CRMs with the same specificity based on its de novo created motifs is comparable to that of previously evaluated ‘motif-blind’ methods. We further show, both in flies and in mammals, that Imogene de novo generated motifs are sufficient to discriminate CRMs related to different developmental programs. Notably, purely relying on sequence data, Imogene performs as well in this discrimination task as a previously reported learning algorithm based on Chromatin Immunoprecipitation (ChIP) data for multiple transcription factors at multiple developmental stages.
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Affiliation(s)
- Hervé Rouault
- Developmental and Stem Cell Biology Department, Institut Pasteur, F-75015 Paris, France CNRS, URA2578, F-75015 Paris, France
| | - Marc Santolini
- Laboratoire de Physique Statistique, CNRS, École Normale Supérieure, Université P. et M. Curie, Université Paris-Diderot
| | - François Schweisguth
- Developmental and Stem Cell Biology Department, Institut Pasteur, F-75015 Paris, France CNRS, URA2578, F-75015 Paris, France
| | - Vincent Hakim
- Laboratoire de Physique Statistique, CNRS, École Normale Supérieure, Université P. et M. Curie, Université Paris-Diderot
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16
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Manojlovic Z, Earwood R, Kato A, Stefanovic B, Kato Y. RFX7 is required for the formation of cilia in the neural tube. Mech Dev 2014; 132:28-37. [PMID: 24530844 DOI: 10.1016/j.mod.2014.02.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 02/04/2014] [Indexed: 12/22/2022]
Abstract
Regulatory Factor X (RFX) transcription factors are important for development and are likely involved in the pathogenesis of serious human diseases including ciliopathies. While seven RFX genes have been identified in vertebrates and several RFX transcription factors have been reported to be regulators of ciliogenesis, the role of RFX7 in development including ciliogenesis is not known. Here we show that RFX7 in Xenopus laevis is expressed in the neural tube, eye, otic vesicles, and somites. Knockdown of RFX7 in Xenopus embryos resulted in a defect of ciliogenesis in the neural tube and failure of neural tube closure. RFX7 controlled the formation of cilia by regulating the expression of RFX4 gene, which has been reported to be required for ciliogenesis in the neural tube. Moreover, ectopic expression of Foxj1, which is a master regulator of motile cilia formation, suppressed the expression of RFX4 but not RFX7. Taken together, RFX7 plays an important role in the process of neural tube closure at the top of the molecular cascade which controls ciliogenesis in the neural tube.
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Affiliation(s)
- Zarko Manojlovic
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL 32306, USA
| | - Ryan Earwood
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL 32306, USA
| | - Akiko Kato
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL 32306, USA
| | - Branko Stefanovic
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL 32306, USA.
| | - Yoichi Kato
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL 32306, USA.
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17
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A potential molecular pathogenesis of cardiac/laterality defects in Oculo-Facio-Cardio-Dental syndrome. Dev Biol 2014; 387:28-36. [PMID: 24440151 DOI: 10.1016/j.ydbio.2014.01.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 01/04/2014] [Accepted: 01/09/2014] [Indexed: 01/16/2023]
Abstract
Pitx2 is the last effector of the left-right (LR) cascade known to date and plays a crucial role in the patterning of LR asymmetry. In Xenopus embryos, the expression of Pitx2 gene in the left lateral plate mesoderm (LPM) is directly regulated by Xnr1 signaling, which is mediated by Smads and FoxH1. Previous studies suggest that the suppression of Pitx2 gene in the left LPM is a potential cause of cardiac/laterality defects in Oculo-Facio-Cardio-Dental (OFCD) syndrome, which is known to be caused by mutations in BCL6 co-repressor (BCOR) gene. Recently, our work has revealed that the BCL6/BCOR complex blocks Notch-dependent transcriptional activity to protect the expression of Pitx2 in the left LPM from the inhibitory activity of Notch signaling. These studies indicated that uncontrolled Notch activity in the left LPM caused by dysfunction of BCOR may result in cardiac/laterality defects of OFCD syndrome. However, this Notch-dependent inhibitory mechanism of Pitx2 gene transcription still remains unknown. Here we report that transcriptional repressor ESR1, which acts downstream of Notch signaling, inhibits the expression of Pitx2 gene by binding to a left side-specific enhancer (ASE) region in Pitx2 gene and recruiting histone deacetylase 1 (HDAC1) to this region. Once HDAC1 is tethered, histone acetyltransferase p300 is no longer recruited to the Xnr1-dependent transcriptional complex on the ASE region, leading to the suppression of Pitx2 gene in the left LPM. The study presented here uncovers the regulatory mechanism of Pitx2 gene transcription which may contribute to an understanding of pathogenesis of OFCD syndrome.
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18
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Dobson-Stone C, Polly P, Korgaonkar MS, Williams LM, Gordon E, Schofield PR, Mather K, Armstrong NJ, Wen W, Sachdev PS, Kwok JBJ. GSK3B and MAPT polymorphisms are associated with grey matter and intracranial volume in healthy individuals. PLoS One 2013; 8:e71750. [PMID: 23951236 PMCID: PMC3741177 DOI: 10.1371/journal.pone.0071750] [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: 04/16/2013] [Accepted: 07/02/2013] [Indexed: 12/12/2022] Open
Abstract
The microtubule-associated protein tau gene (MAPT) codes for a protein that plays an integral role in stabilisation of microtubules and axonal transport in neurons. As well as its role in susceptibility to neurodegeneration, previous studies have found an association between the MAPT haplotype and intracranial volume and regional grey matter volumes in healthy adults. The glycogen synthase kinase-3β gene (GSK3B) codes for a serine/threonine kinase that phosphorylates various proteins, including tau, and has also been associated with risk for neurodegenerative disorders and schizophrenia. We examined the effects of MAPT and two functional promoter polymorphisms in GSK3B (rs3755557 and rs334558) on total grey matter and intracranial volume in three independent cohorts totaling 776 neurologically healthy individuals. In vitro analyses revealed a significant effect of rs3755557 on gene expression, and altered binding of at least two transcription factors, Octamer transcription factor 1 (Oct-1) and Pre-B-cell leukemia transcription factor 1 (Pbx-1), to the GSK3B promoter. Meta-analysis across the three cohorts revealed a significant effect of rs3755557 on total grey matter volume (summary B = 0.082, 95% confidence interval = 0.037–0.128) and intracranial volume (summary B = 0.113, 95% confidence interval = 0.082–0.144). No significant effect was observed for MAPT H1/H2 diplotype or GSK3B rs334558 on total grey matter or intracranial volume. Our genetic and biochemical analyses have identified a role for GSK3B in brain development, which could have important aetiological implications for neurodegenerative and neurodevelopmental disorders.
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Affiliation(s)
- Carol Dobson-Stone
- Neuroscience Research Australia, Randwick, New South Wales, Australia
- Department of Pathology and Inflammation and Infection Research Centre, School of Medical Sciences, University of New South Wales, Kensington, Australia
| | - Patsie Polly
- Department of Pathology and Inflammation and Infection Research Centre, School of Medical Sciences, University of New South Wales, Kensington, Australia
| | - Mayuresh S. Korgaonkar
- The Brain Dynamics Centre, University of Sydney Medical School and Westmead Millennium Institute, Westmead, Australia
| | - Leanne M. Williams
- The Brain Dynamics Centre, University of Sydney Medical School and Westmead Millennium Institute, Westmead, Australia
- Brain Resource International Database, Brain Resource Ltd., Ultimo, Sydney, New South Wales, Australia, and San Francisco, California
| | - Evian Gordon
- Brain Resource International Database, Brain Resource Ltd., Ultimo, Sydney, New South Wales, Australia, and San Francisco, California
| | - Peter R. Schofield
- Neuroscience Research Australia, Randwick, New South Wales, Australia
- Department of Pathology and Inflammation and Infection Research Centre, School of Medical Sciences, University of New South Wales, Kensington, Australia
| | - Karen Mather
- Euroa Centre, Prince of Wales Hospital, Randwick, Australia
| | - Nicola J. Armstrong
- Cancer Program, Garvan Institute of Medical Research, Sydney, Australia, School of Mathematics and Statistics, and Prince of Wales Clinical School, University of New South Wales, Sydney, Australia
| | - Wei Wen
- Euroa Centre, Prince of Wales Hospital, Randwick, Australia
- School of Psychiatry, University of New South Wales, Sydney, Australia
| | - Perminder S. Sachdev
- Euroa Centre, Prince of Wales Hospital, Randwick, Australia
- School of Psychiatry, University of New South Wales, Sydney, Australia
| | - John B. J. Kwok
- Neuroscience Research Australia, Randwick, New South Wales, Australia
- Department of Pathology and Inflammation and Infection Research Centre, School of Medical Sciences, University of New South Wales, Kensington, Australia
- * E-mail:
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19
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D'Amico LA, Boujard D, Coumailleau P. The neurogenic factor NeuroD1 is expressed in post-mitotic cells during juvenile and adult Xenopus neurogenesis and not in progenitor or radial glial cells. PLoS One 2013; 8:e66487. [PMID: 23799108 PMCID: PMC3683004 DOI: 10.1371/journal.pone.0066487] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2013] [Accepted: 05/07/2013] [Indexed: 12/21/2022] Open
Abstract
In contrast to mammals that have limited proliferation and neurogenesis capacities, the Xenopus frog exhibit a great potential regarding proliferation and production of new cells in the adult brain. This ability makes Xenopus a useful model for understanding the molecular programs required for adult neurogenesis. Transcriptional factors that control adult neurogenesis in vertebrate species undergoing widespread neurogenesis are unknown. NeuroD1 is a member of the family of proneural genes, which function during embryonic neurogenesis as a potent neuronal differentiation factor. Here, we study in detail the expression of NeuroD1 gene in the juvenile and adult Xenopus brains by in situ hybridization combined with immunodetections for proliferation markers (PCNA, BrdU) or in situ hybridizations for cell type markers (Vimentin, Sox2). We found NeuroD1 gene activity in many brain regions, including olfactory bulbs, pallial regions of cerebral hemispheres, preoptic area, habenula, hypothalamus, cerebellum and medulla oblongata. We also demonstrated by double staining NeuroD1/BrdU experiments, after long post-BrdU administration survival times, that NeuroD1 gene activity was turned on in new born neurons during post-metamorphic neurogenesis. Importantly, we provided evidence that NeuroD1-expressing cells at this brain developmental stage were post-mitotic (PCNA-) cells and not radial glial (Vimentin+) or progenitors (Sox2+) cells.
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Affiliation(s)
- Laure Anne D'Amico
- Centre de Ressources Biologiques Xénope UMS U3387, CNRS, and Rennes 1 University, Rennes, France
| | - Daniel Boujard
- Centre de Ressources Biologiques Xénope UMS U3387, CNRS, and Rennes 1 University, Rennes, France
| | - Pascal Coumailleau
- Centre de Ressources Biologiques Xénope UMS U3387, CNRS, and Rennes 1 University, Rennes, France
- IRSET U1085, INSERM and Rennes1 University, Rennes, France
- * E-mail:
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20
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Xu Y, Xu C, Kato A, Tempel W, Abreu JG, Bian C, Hu Y, Hu D, Zhao B, Cerovina T, Diao J, Wu F, He HH, Cui Q, Clark E, Ma C, Barbara A, Veenstra GJC, Xu G, Kaiser UB, Liu XS, Sugrue SP, He X, Min J, Kato Y, Shi YG. Tet3 CXXC domain and dioxygenase activity cooperatively regulate key genes for Xenopus eye and neural development. Cell 2012; 151:1200-13. [PMID: 23217707 PMCID: PMC3705565 DOI: 10.1016/j.cell.2012.11.014] [Citation(s) in RCA: 190] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 09/19/2012] [Accepted: 11/09/2012] [Indexed: 11/26/2022]
Abstract
Ten-Eleven Translocation (Tet) family of dioxygenases dynamically regulates DNA methylation and has been implicated in cell lineage differentiation and oncogenesis. Yet their functions and mechanisms of action in gene regulation and embryonic development are largely unknown. Here, we report that Xenopus Tet3 plays an essential role in early eye and neural development by directly regulating a set of key developmental genes. Tet3 is an active 5mC hydroxylase regulating the 5mC/5hmC status at target gene promoters. Biochemical and structural studies further demonstrate that the Tet3 CXXC domain is critical for specific Tet3 targeting. Finally, we show that the enzymatic activity and CXXC domain are both crucial for Tet3's biological function. Together, these findings define Tet3 as a transcription regulator and reveal a molecular mechanism by which the 5mC hydroxylase and DNA binding activities of Tet3 cooperate to control target gene expression and embryonic development.
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Affiliation(s)
- Yufei Xu
- Division of Endocrinology, Diabetes and Hypertension, Departments of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Chao Xu
- Structural Genomics Consortium and Department of Physiology, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - Akiko Kato
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL 32306, USA
| | - Wolfram Tempel
- Structural Genomics Consortium and Department of Physiology, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - Jose Garcia Abreu
- F.M. Kirby Neurobiology Center, Children’s Hospital Boston, Harvard Medical School, Boston, MA 02115, USA
| | - Chuanbing Bian
- Structural Genomics Consortium and Department of Physiology, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - Yeguang Hu
- Division of Endocrinology, Diabetes and Hypertension, Departments of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Di Hu
- Division of Endocrinology, Diabetes and Hypertension, Departments of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
- Laboratory of Epigenetics, Institutes of Biomedical Science, Fudan University, Shanghai 200032, P.R. China
| | - Bin Zhao
- Laboratory of Epigenetics, Institutes of Biomedical Science, Fudan University, Shanghai 200032, P.R. China
| | - Tanja Cerovina
- Structural Genomics Consortium and Department of Physiology, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - Jianbo Diao
- Laboratory of Epigenetics, Institutes of Biomedical Science, Fudan University, Shanghai 200032, P.R. China
| | - Feizhen Wu
- Laboratory of Epigenetics, Institutes of Biomedical Science, Fudan University, Shanghai 200032, P.R. China
| | - Housheng Hansen He
- Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute and Harvard School of Public Health, Boston, MA 02115, USA
| | - Qingyan Cui
- The State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, P.R. China
| | - Erin Clark
- Division of Endocrinology, Diabetes and Hypertension, Departments of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Chun Ma
- Division of Endocrinology, Diabetes and Hypertension, Departments of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
- Laboratory of Epigenetics, Institutes of Biomedical Science, Fudan University, Shanghai 200032, P.R. China
| | - Andrew Barbara
- Division of Endocrinology, Diabetes and Hypertension, Departments of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Gert Jan C. Veenstra
- Radboud University Nijmegen, Nijmegen Center for Molecular Life Sciences, Nijmegen 6500 HB, The Netherlands
| | - Guoliang Xu
- The State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, P.R. China
| | - Ursula B. Kaiser
- Division of Endocrinology, Diabetes and Hypertension, Departments of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - X. Shirley Liu
- Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute and Harvard School of Public Health, Boston, MA 02115, USA
- Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Stephen P. Sugrue
- Department of Anatomy and Cell Biology, University of Florida, Gainesville, FL 32610, USA
| | - Xi He
- F.M. Kirby Neurobiology Center, Children’s Hospital Boston, Harvard Medical School, Boston, MA 02115, USA
| | - Jinrong Min
- Structural Genomics Consortium and Department of Physiology, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - Yoichi Kato
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL 32306, USA
| | - Yujiang Geno Shi
- Division of Endocrinology, Diabetes and Hypertension, Departments of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
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21
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Sox21 promotes hippocampal adult neurogenesis via the transcriptional repression of the Hes5 gene. J Neurosci 2012; 32:12543-57. [PMID: 22956844 DOI: 10.1523/jneurosci.5803-11.2012] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Despite the importance of the production of new neurons in the adult hippocampus, the transcription network governing this process remains poorly understood. The High Mobility Group (HMG)-box transcription factor, Sox2, and the cell surface activated transcriptional regulator, Notch, play important roles in CNS stem cells. Here, we demonstrate that another member of the SoxB (Sox1/Sox2/Sox3) transcription factor family, Sox21, is also a critical regulator of adult neurogenesis in mouse hippocampus. Loss of Sox21 impaired transition of progenitor cells from type 2a to type 2b, thereby reducing subsequent production of new neurons in the adult dentate gyrus. Analysis of the Sox21 binding sites in neural stem/progenitor cells indicated that the Notch-responsive gene, Hes5, was a target of Sox21. Sox21 repressed Hes5 gene expression at the transcriptional level. Simultaneous overexpression of Hes5 and Sox21 revealed that Hes5 was a downstream effector of Sox21 at the point where the Notch and Sox pathways intersect to control the number of neurons in the adult hippocampus. Therefore, Sox21 controls hippocampal adult neurogenesis via transcriptional repression of the Hes5 gene.
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22
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Burzynski GM, Reed X, Taher L, Stine ZE, Matsui T, Ovcharenko I, McCallion AS. Systematic elucidation and in vivo validation of sequences enriched in hindbrain transcriptional control. Genome Res 2012; 22:2278-89. [PMID: 22759862 PMCID: PMC3483557 DOI: 10.1101/gr.139717.112] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Illuminating the primary sequence encryption of enhancers is central to understanding the regulatory architecture of genomes. We have developed a machine learning approach to decipher motif patterns of hindbrain enhancers and identify 40,000 sequences in the human genome that we predict display regulatory control that includes the hindbrain. Consistent with their roles in hindbrain patterning, MEIS1, NKX6-1, as well as HOX and POU family binding motifs contributed strongly to this enhancer model. Predicted hindbrain enhancers are overrepresented at genes expressed in hindbrain and associated with nervous system development, and primarily reside in the areas of open chromatin. In addition, 77 (0.2%) of these predictions are identified as hindbrain enhancers on the VISTA Enhancer Browser, and 26,000 (60%) overlap enhancer marks (H3K4me1 or H3K27ac). To validate these putative hindbrain enhancers, we selected 55 elements distributed throughout our predictions and six low scoring controls for evaluation in a zebrafish transgenic assay. When assayed in mosaic transgenic embryos, 51/55 elements directed expression in the central nervous system. Furthermore, 30/34 (88%) predicted enhancers analyzed in stable zebrafish transgenic lines directed expression in the larval zebrafish hindbrain. Subsequent analysis of sequence fragments selected based upon motif clustering further confirmed the critical role of the motifs contributing to the classifier. Our results demonstrate the existence of a primary sequence code characteristic to hindbrain enhancers. This code can be accurately extracted using machine-learning approaches and applied successfully for de novo identification of hindbrain enhancers. This study represents a critical step toward the dissection of regulatory control in specific neuronal subtypes.
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Affiliation(s)
- Grzegorz M Burzynski
- McKusick-Nathans Institute of Genetic Medicine, Department of Molecular and Comparative Pathobiology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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Alpár A, Attems J, Mulder J, Hökfelt T, Harkany T. The renaissance of Ca2+-binding proteins in the nervous system: secretagogin takes center stage. Cell Signal 2012; 24:378-387. [PMID: 21982882 PMCID: PMC3237847 DOI: 10.1016/j.cellsig.2011.09.028] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Accepted: 09/24/2011] [Indexed: 02/03/2023]
Abstract
Effective control of the Ca(2+) homeostasis in any living cell is paramount to coordinate some of the most essential physiological processes, including cell division, morphological differentiation, and intercellular communication. Therefore, effective homeostatic mechanisms have evolved to maintain the intracellular Ca(2+) concentration at physiologically adequate levels, as well as to regulate the spatial and temporal dynamics of Ca(2+)signaling at subcellular resolution. Members of the superfamily of EF-hand Ca(2+)-binding proteins are effective to either attenuate intracellular Ca(2+) transients as stochiometric buffers or function as Ca(2+) sensors whose conformational change upon Ca(2+) binding triggers protein-protein interactions, leading to cell state-specific intracellular signaling events. In the central nervous system, some EF-hand Ca(2+)-binding proteins are restricted to specific subtypes of neurons or glia, with their expression under developmental and/or metabolic control. Therefore, Ca(2+)-binding proteins are widely used as molecular markers of cell identity whilst also predicting excitability and neurotransmitter release profiles in response to electrical stimuli. Secretagogin is a novel member of the group of EF-hand Ca(2+)-binding proteins whose expression precedes that of many other Ca(2+)-binding proteins in postmitotic, migratory neurons in the embryonic nervous system. Secretagogin expression persists during neurogenesis in the adult brain, yet becomes confined to regionalized subsets of differentiated neurons in the adult central and peripheral nervous and neuroendocrine systems. Secretagogin may be implicated in the control of neuronal turnover and differentiation, particularly since it is re-expressed in neoplastic brain and endocrine tumors and modulates cell proliferation in vitro. Alternatively, and since secretagogin can bind to SNARE proteins, it might function as a Ca(2+) sensor/coincidence detector modulating vesicular exocytosis of neurotransmitters, neuropeptides or hormones. Thus, secretagogin emerges as a functionally multifaceted Ca(2+)-binding protein whose molecular characterization can unravel a new and fundamental dimension of Ca(2+)signaling under physiological and disease conditions in the nervous system and beyond.
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Affiliation(s)
- Alán Alpár
- European Neuroscience Institute at Aberdeen, University of Aberdeen, Aberdeen AB25 2ZD, United Kingdom; Division of Molecular Neurobiology, Department of Medical Biochemistry & Biophysics, Karolinska Institutet, S-17177 Stockholm, Sweden
| | - Johannes Attems
- Institute for Ageing and Health, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne NE4 5PL, United Kingdom
| | - Jan Mulder
- Science for Life Laboratory, Department of Neuroscience, Karolinska Institutet, Tomtebodavägen 23A, S-17165 Solna, Sweden
| | - Tomas Hökfelt
- Department of Neuroscience, Retzius väg 8, Karolinska Institutet, S-17177 Stockholm, Sweden
| | - Tibor Harkany
- European Neuroscience Institute at Aberdeen, University of Aberdeen, Aberdeen AB25 2ZD, United Kingdom; Division of Molecular Neurobiology, Department of Medical Biochemistry & Biophysics, Karolinska Institutet, S-17177 Stockholm, Sweden.
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Yamada A, Koyanagi KO, Watanabe H. In silico and in vivo identification of the intermediate filament vimentin that is downregulated downstream of Brachyury during Xenopus embryogenesis. Gene 2011; 491:232-6. [PMID: 21963995 DOI: 10.1016/j.gene.2011.09.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Revised: 09/08/2011] [Accepted: 09/13/2011] [Indexed: 10/17/2022]
Abstract
Brachyury, a member of the T-box transcription family, has been suggested to be essential for morphogenetic movements in various processes of animal development. However, little is known about its critical transcriptional targets. In order to identify targets of Brachyury and understand the molecular mechanisms underlying morphogenetic movements, we first searched the genome sequence of Xenopus tropicalis, the only amphibian genomic sequence available, for Brachyury-binding sequences known as T-half sites, and then screened for the ones conserved between vertebrate genomes. We found three genes that have evolutionarily conserved T-half sites in the promoter regions and examined these genes experimentally to determine whether their expressions were regulated by Brachyury, using the animal cap system of Xenopus laevis embryos. Eventually, we obtained evidence that vimentin, encoding an intermediate filament protein, was a potential target of Brachyury. This is the first report to demonstrate that Brachyury might affect the cytoskeletal structure through regulating the expression of an intermediate filament protein, vimentin.
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Affiliation(s)
- Atsuko Yamada
- Graduate School of Information Science and Technology, Hokkaido University, Sapporo, Hokkaido 060-0814, Japan
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25
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D'Amico LA, Boujard D, Coumailleau P. Proliferation, migration and differentiation in juvenile and adult Xenopus laevis brains. Brain Res 2011; 1405:31-48. [DOI: 10.1016/j.brainres.2011.06.032] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Revised: 06/10/2011] [Accepted: 06/11/2011] [Indexed: 11/25/2022]
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Abstract
The Notch pathway is prominent among those known to regulate neural development in vertebrates. Notch receptor activation can inhibit neurogenesis, maintain neural progenitor character, and in some contexts promote gliogenesis and drive binary fate choices. Recently, a wave of exciting studies has emerged, which has both solidified previously held assertions and expanded our understanding of Notch function during neurogenesis and in the adult brain. These studies have examined pathway regulators and interactions, as well as pathway dynamics, with respect to both gene expression and cell-cell signaling. Here, focusing primarily on vertebrates, we review the current literature on Notch signaling in the nervous system, and highlight numerous recent studies that have generated interesting and unexpected advances.
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Wang P, Jin T. Hydrogen peroxide stimulates nuclear import of the POU homeodomain protein Oct-1 and its repressive effect on the expression of Cdx-2. BMC Cell Biol 2010; 11:56. [PMID: 20637099 PMCID: PMC2913919 DOI: 10.1186/1471-2121-11-56] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2009] [Accepted: 07/16/2010] [Indexed: 11/24/2022] Open
Abstract
Background The ubiquitously expressed POU homeodomain protein Oct-1 serves as a sensor for stress induced by irradiation. We found recently that in pancreatic and intestinal endocrine cells, Oct-1 also functions as a sensor for cyclic AMP (cAMP). The caudal homeobox gene Cdx-2 is a transactivator of proglucagon (gcg) and pro-insulin genes. Oct-1 binds to Cdx-2 promoter and represses its expression. cAMP elevation leads to increased nuclear exclusion of Oct-1, associated with reduced recruitment of nuclear co-repressors to the Cdx-2 promoter and increased Cdx-2 expression. Results We show in this study that inducing oxidative stress by hydrogen peroxide (H2O2) increased nuclear Oct-1 content in both pancreatic α and β cell lines, as well as in a battery of other cells. This increase was then attributed to accelerated nuclear import of Oct-1, assessed by Fluorescence Recovery After Photobleaching (FRAP) using green fluorescence protein (EGFP) tagged Oct-1 molecule. H2O2 treatment was then shown to stimulate the activities of DNA-dependent protein kinase (DNA-PK) and c-jun N-terminal kinase (JNK). Finally, increased Oct-1 nuclear content upon H2O2 treatment in a pancreatic α cell line was associated with reduced Cdx-2 and gcg mRNA expression. Conclusion These observations suggest that Oct-1 functions as a sensor for both metabolic and stress/survival signaling pathways via altering its nuclear-cytoplasmic shuttling.
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Affiliation(s)
- Peixiang Wang
- Div of Cell and Molecular Biology, Toronto General Research Institute, University Health Network, 10-354 Toronto Medical Discovery Tower, The MaRS Building, 101 College St, Toronto, Ontario M5G 1L7, Canada
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28
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Martinez-de Luna RI, Moose HE, Kelly LE, Nekkalapudi S, El-Hodiri HM. Regulation of retinal homeobox gene transcription by cooperative activity among cis-elements. Gene 2010; 467:13-24. [PMID: 20627122 DOI: 10.1016/j.gene.2010.07.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2010] [Revised: 06/29/2010] [Accepted: 07/06/2010] [Indexed: 12/23/2022]
Abstract
The retinal homeobox (Rx/rax) gene is essential for the development of the eye. Rax is among the earliest genes expressed during eye development, beginning in the prospective eye fields in the anterior neural plate. Additionally Rax expression persists in retinal progenitor cells and in differentiated photoreceptors. We have isolated and characterized a 2.8 kb genomic DNA fragment that regulates expression of Rax in the developing and maturing retina. We have discovered and characterized cis-acting elements that function to specifically control spatial and temporal Rax expression during retinal development. We have found that the regulation of Rax2A promoter activity requires cooperative interactions between positive and negative regulatory elements. Further, a highly conserved genomic element containing SOX, OTX, and POU transcription factor binding sites is necessary but not sufficient for promoter activity in retinal progenitor or stem cells. Finally, a putative binding element for forkhead transcription factors is necessary for promoter activity and can cooperate with other cis-acting elements to drive Rax2A promoter activity.
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Affiliation(s)
- Reyna I Martinez-de Luna
- Graduate Program in Molecular, Cellular, and Developmental Biology, College of Biological Sciences, The Ohio State University, Columbus, OH, USA
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29
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Wang P, Wang Q, Sun J, Wu J, Li H, Zhang N, Huang Y, Su B, Li RK, Liu L, Zhang Y, Elsholtz HP, Hu J, Gaisano HY, Jin T. POU homeodomain protein Oct-1 functions as a sensor for cyclic AMP. J Biol Chem 2009; 284:26456-65. [PMID: 19617623 PMCID: PMC2785334 DOI: 10.1074/jbc.m109.030668] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2009] [Revised: 07/15/2009] [Indexed: 01/30/2023] Open
Abstract
Cyclic AMP is a fundamentally important second messenger for numerous peptide hormones and neurotransmitters that control gene expression, cell proliferation, and metabolic homeostasis. Here we show that cAMP works with the POU homeodomain protein Oct-1 to regulate gene expression in pancreatic and intestinal endocrine cells. This ubiquitously expressed transcription factor is known as a stress sensor. We found that it also functions as a repressor of Cdx-2, a proglucagon gene activator. Through a mechanism that involves the activation of exchange protein activated by cyclic AMP, elevation of cAMP leads to enhanced phosphorylation and nuclear exclusion of Oct-1 and reduced interactions between Oct-1 or nuclear co-repressors and the Cdx-2 gene promoter, detected by chromatin immunoprecipitation. In rat primary pancreatic islet cells, cAMP elevation also reduces nuclear Oct-1 content, which causes increased proglucagon and proinsulin mRNA expression. Our study therefore identifies a novel mechanism by which cAMP regulates hormone-gene expression and suggests that ubiquitously expressed Oct-1 may play a role in metabolic homeostasis by functioning as a sensor for cAMP.
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Affiliation(s)
| | - Qinghua Wang
- the Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- the Division of Endocrinology and Metabolism, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario M5B 1W8, Canada, and
| | - Jane Sun
- From the Division of Cell and Molecular Biology and
- the Departments of Laboratory Medicine and Pathobiology and
| | - Jing Wu
- the **Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - Hang Li
- From the Division of Cell and Molecular Biology and
| | - Nina Zhang
- the Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- the Division of Endocrinology and Metabolism, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario M5B 1W8, Canada, and
| | - Yachi Huang
- the Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Brenda Su
- Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, Toronto, Ontario M5G 1L7, Canada
| | - Ren-ke Li
- Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, Toronto, Ontario M5G 1L7, Canada
| | - Ling Liu
- From the Division of Cell and Molecular Biology and
| | - Yi Zhang
- the Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | | | - Jim Hu
- the Departments of Laboratory Medicine and Pathobiology and
- the **Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - Herbert Y. Gaisano
- the Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- Medicine, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - Tianru Jin
- From the Division of Cell and Molecular Biology and
- the Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- the Departments of Laboratory Medicine and Pathobiology and
- Medicine, University of Toronto, Toronto, Ontario M5G 1L7, Canada
- the Department of Nutrition, School of Public Health, Sun Yat-sen University, 510080 Guangzhou, China
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30
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Miazga CM, McLaughlin KA. Coordinating the timing of cardiac precursor development during gastrulation: A new role for Notch signaling. Dev Biol 2009; 333:285-96. [DOI: 10.1016/j.ydbio.2009.06.040] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Revised: 06/16/2009] [Accepted: 06/27/2009] [Indexed: 10/20/2022]
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Ethanol inhibition of aspartyl-asparaginyl-beta-hydroxylase in fetal alcohol spectrum disorder: potential link to the impairments in central nervous system neuronal migration. Alcohol 2009; 43:225-40. [PMID: 19393862 DOI: 10.1016/j.alcohol.2008.09.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2008] [Revised: 08/20/2008] [Accepted: 09/17/2008] [Indexed: 12/30/2022]
Abstract
Fetal alcohol spectrum disorder (FASD) is caused by prenatal exposure to alcohol and associated with hypoplasia and impaired neuronal migration in the cerebellum. Neuronal survival and motility are stimulated by insulin and insulin-like growth factor (IGF), whose signaling pathways are major targets of ethanol neurotoxicity. To better understand the mechanisms of ethanol-impaired neuronal migration during development, we examined the effects of chronic gestational exposure to ethanol on aspartyl (asparaginyl)-beta-hydroxylase (AAH) expression, because AAH is regulated by insulin/IGF and mediates neuronal motility. Pregnant Long-Evans rats were pair-fed isocaloric liquid diets containing 0, 8, 18, 26, or 37% ethanol by caloric content from gestation day 6 through delivery. Cerebella harvested from postnatal day 1 pups were used to examine AAH expression in tissue, and neuronal motility in Boyden chamber assays. We also used cerebellar neuron cultures to examine the effects of ethanol on insulin/IGF-stimulated AAH expression, and assess the role of GSK-3beta-mediated phosphorylation on AAH protein levels. Chronic gestational exposure to ethanol caused dose-dependent impairments in neuronal migration and corresponding reductions in AAH protein expression in developing cerebella. In addition, prenatal ethanol exposure inhibited insulin and IGF-I-stimulated directional motility in isolated cerebellar granule neurons. Ethanol-treated neuronal cultures (50mMx96h) also had reduced levels of AAH protein. Mechanistically, we showed that AAH protein could be phosphorylated on Ser residues by GSK-3beta, and that chemical inhibition of GSK-3beta and/or global Caspases increases AAH protein in both control- and ethanol-exposed cells. Ethanol-impaired neuronal migration in FASD is associated with reduced AAH expression. Because ethanol increases the activities of both GSK-3beta and Caspases, the inhibitory effect of ethanol on neuronal migration could be mediated by increased GSK-3beta phosphorylation and Caspase degradation of AAH protein.
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Lewis MA, Quint E, Glazier AM, Fuchs H, De Angelis MH, Langford C, van Dongen S, Abreu-Goodger C, Piipari M, Redshaw N, Dalmay T, Moreno-Pelayo MA, Enright AJ, Steel KP. An ENU-induced mutation of miR-96 associated with progressive hearing loss in mice. Nat Genet 2009; 41:614-8. [PMID: 19363478 PMCID: PMC2705913 DOI: 10.1038/ng.369] [Citation(s) in RCA: 242] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2008] [Accepted: 02/13/2009] [Indexed: 12/25/2022]
Abstract
Progressive hearing loss is common in the human population, but little is known about the molecular basis. We report a new N-ethyl-N-nitrosurea (ENU)-induced mouse mutant, diminuendo, with a single base change in the seed region of Mirn96. Heterozygotes show progressive loss of hearing and hair cell anomalies, whereas homozygotes have no cochlear responses. Most microRNAs are believed to downregulate target genes by binding to specific sites on their mRNAs, so mutation of the seed should lead to target gene upregulation. Microarray analysis revealed 96 transcripts with significantly altered expression in homozygotes; notably, Slc26a5, Ocm, Gfi1, Ptprq and Pitpnm1 were downregulated. Hypergeometric P-value analysis showed that hundreds of genes were upregulated in mutants. Different genes, with target sites complementary to the mutant seed, were downregulated. This is the first microRNA found associated with deafness, and diminuendo represents a model for understanding and potentially moderating progressive hair cell degeneration in hearing loss more generally.
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Dennis MY, Paracchini S, Scerri TS, Prokunina-Olsson L, Knight JC, Wade-Martins R, Coggill P, Beck S, Green ED, Monaco AP. A common variant associated with dyslexia reduces expression of the KIAA0319 gene. PLoS Genet 2009; 5:e1000436. [PMID: 19325871 PMCID: PMC2653637 DOI: 10.1371/journal.pgen.1000436] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2008] [Accepted: 02/24/2009] [Indexed: 11/19/2022] Open
Abstract
Numerous genetic association studies have implicated the KIAA0319 gene on human chromosome 6p22 in dyslexia susceptibility. The causative variant(s) remains unknown but may modulate gene expression, given that (1) a dyslexia-associated haplotype has been implicated in the reduced expression of KIAA0319, and (2) the strongest association has been found for the region spanning exon 1 of KIAA0319. Here, we test the hypothesis that variant(s) responsible for reduced KIAA0319 expression resides on the risk haplotype close to the gene's transcription start site. We identified seven single-nucleotide polymorphisms on the risk haplotype immediately upstream of KIAA0319 and determined that three of these are strongly associated with multiple reading-related traits. Using luciferase-expressing constructs containing the KIAA0319 upstream region, we characterized the minimal promoter and additional putative transcriptional regulator regions. This revealed that the minor allele of rs9461045, which shows the strongest association with dyslexia in our sample (max p-value = 0.0001), confers reduced luciferase expression in both neuronal and non-neuronal cell lines. Additionally, we found that the presence of this rs9461045 dyslexia-associated allele creates a nuclear protein-binding site, likely for the transcriptional silencer OCT-1. Knocking down OCT-1 expression in the neuronal cell line SHSY5Y using an siRNA restores KIAA0319 expression from the risk haplotype to nearly that seen from the non-risk haplotype. Our study thus pinpoints a common variant as altering the function of a dyslexia candidate gene and provides an illustrative example of the strategic approach needed to dissect the molecular basis of complex genetic traits. Dyslexia, or reading disability, is a common disorder caused by both genetic and environmental factors. Genetic studies have implicated a number of genes as candidates for playing a role in dyslexia. We functionally characterized one such gene (KIAA0319) to identify variant(s) that might affect gene expression and contribute to the disorder. We discovered a variant residing outside of the protein-coding region of KIAA0319 that reduces expression of the gene. This variant creates a binding site for the transcription factor OCT-1. Previous studies have shown that OCT-1 binding to a specific DNA sequence upstream of a gene can reduce the expression of that gene. In this case, reduced KIAA0319 expression could lead to improper development of regions of the brain involved in reading ability. This is the first study to identify a functional variant implicated in dyslexia. More broadly, our study illustrates the steps that can be utilized for identifying mutations causing other complex genetic disorders.
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Affiliation(s)
- Megan Y. Dennis
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
- Genome Technology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Silvia Paracchini
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Thomas S. Scerri
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Ludmila Prokunina-Olsson
- Laboratory of Translational Genomics, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Gaithersburg, Maryland, United States of America
| | - Julian C. Knight
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Richard Wade-Martins
- Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford, United Kingdom
| | - Penny Coggill
- Wellcome Trust Sanger Institute, Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Stephan Beck
- UCL Cancer Institute, University College London, London, United Kingdom
| | - Eric D. Green
- Genome Technology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail: (EDG); (APM)
| | - Anthony P. Monaco
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
- * E-mail: (EDG); (APM)
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Meng XF, Luo Y, Xiao W, Li M, Shi J. Cloning and Characterization of the Promoter of the Human AHI1 Gene. Biochem Genet 2009; 47:427-38. [DOI: 10.1007/s10528-009-9232-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2008] [Accepted: 09/08/2008] [Indexed: 11/27/2022]
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