1
|
Szczepanski AP, Tsuboyama N, Watanabe J, Hashizume R, Zhao Z, Wang L. POU2AF2/C11orf53 functions as a coactivator of POU2F3 by maintaining chromatin accessibility and enhancer activity. Sci Adv 2022; 8:eabq2403. [PMID: 36197978 PMCID: PMC9534498 DOI: 10.1126/sciadv.abq2403] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Small cell lung cancer (SCLC), accounting for around 13% of all lung cancers, often results in rapid tumor growth, early metastasis, and acquired therapeutic resistance. The POU class 2 homeobox 3 (POU2F3) is a master regulator of tuft cell identity and defines the SCLC-P subtype that lacks the neuroendocrine markers. Here, we have identified a previously uncharacterized protein, C11orf53, which is coexpressed with POU2F3 in both SCLC cell lines and patient samples. Mechanistically, C11orf53 directly interacts with POU2F3 and is recruited to chromatin by POU2F3. Depletion of C11orf53 reduced enhancer H3K27ac levels and chromatin accessibility, resulting in a reduction of POU2F3-dependent gene expression. On the basis of the molecular function of C11orf53, we renamed it as "POU Class 2 Homeobox Associating Factor 2" (POU2AF2). In summary, our study has identified a new coactivator of POU2F3 and sheds light on the therapeutic potential of targeting POU2AF2/POU2F3 heterodimer in human SCLC.
Collapse
Affiliation(s)
- Aileen Patricia Szczepanski
- Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Simpson Querrey Center for Epigenetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Natsumi Tsuboyama
- Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Simpson Querrey Center for Epigenetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Jun Watanabe
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, 303 East Superior St., Chicago, IL 60611, USA
- Division of Hematology, Oncology, Neuro-Oncology & Stem Cell Transplantation, Ann & Robert H. Lurie Children’s Hospital of Chicago, 225 East Chicago Avenue, Box 205, Chicago, IL 60611, USA
| | - Rintaro Hashizume
- Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, 303 East Superior St., Chicago, IL 60611, USA
- Division of Hematology, Oncology, Neuro-Oncology & Stem Cell Transplantation, Ann & Robert H. Lurie Children’s Hospital of Chicago, 225 East Chicago Avenue, Box 205, Chicago, IL 60611, USA
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Zibo Zhao
- Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Simpson Querrey Center for Epigenetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Corresponding author. Email (Z.Z.); (L.W.)
| | - Lu Wang
- Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Simpson Querrey Center for Epigenetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
- Corresponding author. Email (Z.Z.); (L.W.)
| |
Collapse
|
2
|
Gupta A, Storey KB. Coordinated expression of Jumonji and AHCY under OCT transcription factor control to regulate gene methylation in wood frogs during anoxia. Gene 2021; 788:145671. [PMID: 33887369 DOI: 10.1016/j.gene.2021.145671] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 04/05/2021] [Accepted: 04/15/2021] [Indexed: 12/17/2022]
Abstract
Wood frogs (Rana sylvatica) can survive extended periods of whole body freezing. Freezing imparts multiple stresses on cells that include anoxia and dehydration, but these can also be experienced as independent stresses. Under anoxia stress, energy metabolism is suppressed, and pro-survival pathways are prioritized to differentially regulate some transcription factors including OCT1 and OCT4. Jumonji C domain proteins (JMJD1A and JMJD2C) are hypoxia responsive demethylases whose expression is accelerated by OCT1 and OCT4 which act to demethylate genes related to the methionine cycle. The responses by these factors to 24 h anoxia exposure and 4 h aerobic recovery was analyzed in liver and skeletal muscle of wood frogs to assess their involvement in metabolic adaptation to oxygen limitation. Immunoblot results showed a decrease in JMJD1A levels under anoxia in liver and muscle, but an increase was observed in JMJD2C demethylase protein in anoxic skeletal muscle. Protein levels of adenosylhomocysteinase (AHCY) and methionine adenosyl transferase (MAT), enzymes of the methionine cycle, also showed an increase in the reoxygenated liver, whereas the levels decreased in muscle. A transcription factor ELISA showed a decrease in DNA binding by OCT1 in the reoxygenated liver and anoxic skeletal muscle, and transcript levels also showed tissue specific gene expression. The present study provides the first analysis of the role of the OCT1 transcription factor, associated proteins, and lysine demethylases in mediating responses to anoxia by wood frog tissues.
Collapse
Affiliation(s)
- Aakriti Gupta
- Department of Biology, Carleton University, Ottawa K1S 5B6, Canada
| | - Kenneth B Storey
- Department of Biology, Carleton University, Ottawa K1S 5B6, Canada.
| |
Collapse
|
3
|
Chauhan L, Ram U, Hari K, Jolly MK. Topological signatures in regulatory network enable phenotypic heterogeneity in small cell lung cancer. eLife 2021; 10:e64522. [PMID: 33729159 PMCID: PMC8012062 DOI: 10.7554/elife.64522] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Accepted: 03/16/2021] [Indexed: 02/07/2023] Open
Abstract
Phenotypic (non-genetic) heterogeneity has significant implications for the development and evolution of organs, organisms, and populations. Recent observations in multiple cancers have unraveled the role of phenotypic heterogeneity in driving metastasis and therapy recalcitrance. However, the origins of such phenotypic heterogeneity are poorly understood in most cancers. Here, we investigate a regulatory network underlying phenotypic heterogeneity in small cell lung cancer, a devastating disease with no molecular targeted therapy. Discrete and continuous dynamical simulations of this network reveal its multistable behavior that can explain co-existence of four experimentally observed phenotypes. Analysis of the network topology uncovers that multistability emerges from two teams of players that mutually inhibit each other, but members of a team activate one another, forming a 'toggle switch' between the two teams. Deciphering these topological signatures in cancer-related regulatory networks can unravel their 'latent' design principles and offer a rational approach to characterize phenotypic heterogeneity in a tumor.
Collapse
Affiliation(s)
- Lakshya Chauhan
- Centre for BioSystems Science and Engineering, Indian Institute of ScienceBangaloreIndia
- Undergraduate Programme, Indian Institute of ScienceBangaloreIndia
| | - Uday Ram
- Centre for BioSystems Science and Engineering, Indian Institute of ScienceBangaloreIndia
- Undergraduate Programme, Indian Institute of ScienceBangaloreIndia
| | - Kishore Hari
- Centre for BioSystems Science and Engineering, Indian Institute of ScienceBangaloreIndia
| | - Mohit Kumar Jolly
- Centre for BioSystems Science and Engineering, Indian Institute of ScienceBangaloreIndia
| |
Collapse
|
4
|
Zhang G, Yan G, Fu Z, Wu Y, Wu F, Zheng Z, Fang S, Gao Y, Bao X, Liu Y, Wang X, Zhu S. Loss of retinoic acid receptor-related receptor alpha (Rorα) promotes the progression of UV-induced cSCC. Cell Death Dis 2021; 12:247. [PMID: 33664254 PMCID: PMC7933246 DOI: 10.1038/s41419-021-03525-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Revised: 02/09/2021] [Accepted: 02/12/2021] [Indexed: 12/15/2022]
Abstract
Cutaneous squamous cell carcinoma (cSCC) is prevalent in the world, accounting for a huge part of non-melanoma skin cancer. Most cSCCs are associated with a distinct pre-cancerous lesion, the actinic keratosis (AK). However, the progression trajectory from normal skin to AK and cSCC has not been fully demonstrated yet. To identify genes involved in this progression trajectory and possible therapeutic targets for cSCC, here we constructed a UV-induced cSCC mouse model covering the progression from normal skin to AK to cSCC, which mimicked the solar UV radiation perfectly using the solar-like ratio of UVA and UVB, firstly. Then, transcriptome analysis and a series of bioinformatics analyses and cell experiments proved that Rorα is a key transcript factor during cSCC progression. Rorα could downregulate the expressions of S100a9 and Sprr2f in cSCC cells, which can inhibit the proliferation and migration in cSCC cells, but not the normal keratinocyte. Finally, further animal experiments confirmed the inhibitory effect of cSCC growth by Rorα in vivo. Our findings showed that Rorα would serve as a potential novel target for cSCC, which will facilitate the treatment of cSCC in the future.
Collapse
MESH Headings
- Animals
- Calgranulin B/genetics
- Calgranulin B/metabolism
- Carcinoma, Squamous Cell/etiology
- Carcinoma, Squamous Cell/genetics
- Carcinoma, Squamous Cell/metabolism
- Carcinoma, Squamous Cell/pathology
- Cell Line, Tumor
- Cell Movement
- Cell Proliferation
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/metabolism
- Cell Transformation, Neoplastic/pathology
- Cornified Envelope Proline-Rich Proteins/genetics
- Cornified Envelope Proline-Rich Proteins/metabolism
- Disease Models, Animal
- Disease Progression
- Female
- Gene Expression Regulation, Neoplastic
- Humans
- Keratosis, Actinic/etiology
- Keratosis, Actinic/genetics
- Keratosis, Actinic/metabolism
- Keratosis, Actinic/pathology
- Mice, Hairless
- Neoplasm Invasiveness
- Neoplasms, Radiation-Induced/etiology
- Neoplasms, Radiation-Induced/genetics
- Neoplasms, Radiation-Induced/metabolism
- Neoplasms, Radiation-Induced/pathology
- Nuclear Receptor Subfamily 1, Group F, Member 1/deficiency
- Nuclear Receptor Subfamily 1, Group F, Member 1/genetics
- Octamer Transcription Factors/genetics
- Octamer Transcription Factors/metabolism
- Skin Neoplasms/etiology
- Skin Neoplasms/genetics
- Skin Neoplasms/metabolism
- Skin Neoplasms/pathology
- Transcriptome
- Ultraviolet Rays
- Mice
Collapse
Affiliation(s)
- Guolong Zhang
- Institute of Photomedicine, Shanghai Skin Disease Hospital, Tongji University School of Medicine, Shanghai, 200443, China
| | - Guorong Yan
- Institute of Photomedicine, Shanghai Skin Disease Hospital, Tongji University School of Medicine, Shanghai, 200443, China
| | - Zhiliang Fu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438, China
- Department of Epidemiology, School of Public Health, Fudan University, Shanghai, 200438, China
| | - Yuhao Wu
- Institute of Photomedicine, Shanghai Skin Disease Hospital, Tongji University School of Medicine, Shanghai, 200443, China
| | - Fei Wu
- Department of Pathology, Shanghai Skin Disease Hospital, Tongji University School of Medicine, Shanghai, 200443, China
| | - Zhe Zheng
- Institute of Photomedicine, Shanghai Skin Disease Hospital, Tongji University School of Medicine, Shanghai, 200443, China
| | - Shan Fang
- Institute of Photomedicine, Shanghai Skin Disease Hospital, Tongji University School of Medicine, Shanghai, 200443, China
| | - Ying Gao
- Institute of Photomedicine, Shanghai Skin Disease Hospital, Tongji University School of Medicine, Shanghai, 200443, China
| | - Xunxia Bao
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438, China
- Department of Epidemiology, School of Public Health, Fudan University, Shanghai, 200438, China
| | - Yeqiang Liu
- Department of Pathology, Shanghai Skin Disease Hospital, Tongji University School of Medicine, Shanghai, 200443, China.
| | - Xiuli Wang
- Institute of Photomedicine, Shanghai Skin Disease Hospital, Tongji University School of Medicine, Shanghai, 200443, China.
| | - Sibo Zhu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438, China.
- Department of Epidemiology, School of Public Health, Fudan University, Shanghai, 200438, China.
| |
Collapse
|
5
|
Kim KP, Choi J, Yoon J, Bruder JM, Shin B, Kim J, Arauzo-Bravo MJ, Han D, Wu G, Han DW, Kim J, Cramer P, Schöler HR. Permissive epigenomes endow reprogramming competence to transcriptional regulators. Nat Chem Biol 2021; 17:47-56. [PMID: 32807969 DOI: 10.1038/s41589-020-0618-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 07/08/2020] [Indexed: 01/09/2023]
Abstract
Identifying molecular and cellular processes that regulate reprogramming competence of transcription factors broadens our understanding of reprogramming mechanisms. In the present study, by a chemical screen targeting major epigenetic pathways in human reprogramming, we discovered that inhibiting specific epigenetic roadblocks including disruptor of telomeric silencing 1-like (DOT1L)-mediated H3K79/K27 methylation, but also other epigenetic pathways, catalyzed by lysine-specific histone demethylase 1A, DNA methyltransferases and histone deacetylases, allows induced pluripotent stem cell generation with almost all OCT factors. We found that simultaneous inhibition of these pathways not only dramatically enhances reprogramming competence of most OCT factors, but in fact enables dismantling of species-dependent reprogramming competence of OCT6, NR5A1, NR5A2, TET1 and GATA3. Harnessing these induced permissive epigenetic states, we performed an additional screen with 98 candidate genes. Thereby, we identified 25 transcriptional regulators (OTX2, SIX3, and so on) that can functionally replace OCT4 in inducing pluripotency. Our findings provide a conceptual framework for understanding how transcription factors elicit reprogramming in dependency of the donor cell epigenome that differs across species.
Collapse
Affiliation(s)
- Kee-Pyo Kim
- Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany
| | - Jinmi Choi
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Juyong Yoon
- Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany
- Department of Early Discovery, Ksilink, Strasbourg, France
| | - Jan M Bruder
- Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany
| | - Borami Shin
- Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany
| | - Jonghun Kim
- Department of Stem Cell Biology, School of Medicine, Konkuk University, Seoul, Republic of Korea
- Department of Genetics, Yale School of Medicine, New Haven, CT, USA
| | - Marcos J Arauzo-Bravo
- Group of Computational Biology and Systems Biomedicine, Biodonostia Health Research Institute, San Sebastian, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - Dong Han
- Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany
| | - Guangming Wu
- Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany
- Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, China
| | - Dong Wook Han
- School of Biotechnology and Healthcare, Wuyi University, Jiangmen, China
| | - Johnny Kim
- Department of Cardiac Development and Remodeling, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Patrick Cramer
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Hans R Schöler
- Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany.
- Medical Faculty, University of Münster, Münster, Germany.
| |
Collapse
|
6
|
DelGiorno KE, Chung CY, Vavinskaya V, Maurer HC, Novak SW, Lytle NK, Ma Z, Giraddi RR, Wang D, Fang L, Naeem RF, Andrade LR, Ali WH, Tseng H, Tsui C, Gubbala VB, Ridinger-Saison M, Ohmoto M, Erikson GA, O'Connor C, Shokhirev MN, Hah N, Urade Y, Matsumoto I, Kaech SM, Singh PK, Manor U, Olive KP, Wahl GM. Tuft Cells Inhibit Pancreatic Tumorigenesis in Mice by Producing Prostaglandin D 2. Gastroenterology 2020; 159:1866-1881.e8. [PMID: 32717220 PMCID: PMC7680354 DOI: 10.1053/j.gastro.2020.07.037] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 07/12/2020] [Accepted: 07/20/2020] [Indexed: 12/20/2022]
Abstract
BACKGROUND & AIMS Development of pancreatic ductal adenocarcinoma (PDA) involves acinar to ductal metaplasia and genesis of tuft cells. It has been a challenge to study these rare cells because of the lack of animal models. We investigated the role of tuft cells in pancreatic tumorigenesis. METHODS We performed studies with LSL-KrasG12D/+;Ptf1aCre/+ mice (KC; develop pancreatic tumors), KC mice crossed with mice with pancreatic disruption of Pou2f3 (KPouC mice; do not develop tuft cells), or mice with pancreatic disruption of the hematopoietic prostaglandin D synthase gene (Hpgds, KHC mice) and wild-type mice. Mice were allowed to age or were given caerulein to induce pancreatitis; pancreata were collected and analyzed by histology, immunohistochemistry, RNA sequencing, ultrastructural microscopy, and metabolic profiling. We performed laser-capture dissection and RNA-sequencing analysis of pancreatic tissues from 26 patients with pancreatic intraepithelial neoplasia (PanIN), 19 patients with intraductal papillary mucinous neoplasms (IPMNs), and 197 patients with PDA. RESULTS Pancreata from KC mice had increased formation of tuft cells and higher levels of prostaglandin D2 than wild-type mice. Pancreas-specific deletion of POU2F3 in KC mice (KPouC mice) resulted in a loss of tuft cells and accelerated tumorigenesis. KPouC mice had increased fibrosis and activation of immune cells after administration of caerulein. Pancreata from KPouC and KHC mice had significantly lower levels of prostaglandin D2, compared with KC mice, and significantly increased numbers of PanINs and PDAs. KPouC and KHC mice had increased pancreatic injury after administration of caerulein, significantly less normal tissue, more extracellular matrix deposition, and higher PanIN grade than KC mice. Human PanIN and intraductal papillary mucinous neoplasm had gene expression signatures associated with tuft cells and increased expression of Hpgds messenger RNA compared with PDA. CONCLUSIONS In mice with KRAS-induced pancreatic tumorigenesis, loss of tuft cells accelerates tumorigenesis and increases the severity of caerulein-induced pancreatic injury, via decreased production of prostaglandin D2. These data are consistent with the hypothesis that tuft cells are a metaplasia-induced tumor attenuating cell type.
Collapse
Affiliation(s)
- Kathleen E DelGiorno
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, California.
| | - Chi-Yeh Chung
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, California
| | - Vera Vavinskaya
- Department of Pathology, University of California San Diego, San Diego, California
| | - H Carlo Maurer
- Department of Medicine, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, New York; Klinik und Poliklinik für Innere Medizin II, Klinikum rechts der Isar, Technical University, Munich, Germany
| | - Sammy Weiser Novak
- Waitt Advanced Biophotonics Center, Salk Insitute for Biological Studies, La Jolla, California
| | - Nikki K Lytle
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, California
| | - Zhibo Ma
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, California
| | - Rajshekhar R Giraddi
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, California
| | - Dezhen Wang
- Eppley Institute for Research in Cancer, University of Nebraska Medical Center, Omaha, Nebraska
| | - Linjing Fang
- Waitt Advanced Biophotonics Center, Salk Insitute for Biological Studies, La Jolla, California
| | - Razia F Naeem
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, California
| | - Leonardo R Andrade
- Waitt Advanced Biophotonics Center, Salk Insitute for Biological Studies, La Jolla, California
| | - Wahida H Ali
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, California
| | - Hubert Tseng
- Immunobiology and Microbial Pathogenesis Laboratory, Salk Institute for Biological Studies, La Jolla, Califonia
| | - Crystal Tsui
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, California
| | - Vikas B Gubbala
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, California
| | - Maya Ridinger-Saison
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, California
| | - Makoto Ohmoto
- Monell Chemical Senses Center, Philadelphia, Pennsylvania
| | - Galina A Erikson
- Razavi Newman Integrative Genomics and Bioinformatics Core, Salk Institute for Biological Studies, La Jolla, California
| | - Carolyn O'Connor
- Flow Cytometry Core, Salk Insitute for Biological Studies, La Jolla, California
| | - Maxim Nikolaievich Shokhirev
- Razavi Newman Integrative Genomics and Bioinformatics Core, Salk Institute for Biological Studies, La Jolla, California
| | - Nasun Hah
- Next Generation Sequencing Core, Salk Institute for Biological Studies, La Jolla, California
| | | | | | - Susan M Kaech
- Immunobiology and Microbial Pathogenesis Laboratory, Salk Institute for Biological Studies, La Jolla, Califonia
| | - Pankaj K Singh
- Eppley Institute for Research in Cancer, University of Nebraska Medical Center, Omaha, Nebraska
| | - Uri Manor
- Waitt Advanced Biophotonics Center, Salk Insitute for Biological Studies, La Jolla, California
| | - Kenneth P Olive
- Department of Medicine, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, New York
| | - Geoffrey M Wahl
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, California.
| |
Collapse
|
7
|
AlMatrouk A, Lemons K, Ogura T, Luo W, Wilson C, Lin W. Chemical Exposure-Induced Changes in the Expression of Neurotrophins and Their Receptors in the Main Olfactory System of Mice Lacking TRPM5-Expressing Microvillous Cells. Int J Mol Sci 2018; 19:E2939. [PMID: 30261693 PMCID: PMC6213160 DOI: 10.3390/ijms19102939] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 08/25/2018] [Accepted: 09/24/2018] [Indexed: 12/27/2022] Open
Abstract
Functional maintenance of the mammalian main olfactory epithelium (MOE) is challenging because of its direct exposure to a wide spectrum of environmental chemicals. We previously reported that transient receptor potential channel M5-expressing microvillous cells (TRPM5-MCs) in the MOE play an important role in olfactory maintenance. To investigate the underpinning mechanisms, we exposed transcription factor Skn-1a knockout (Skn-1a-/-) mice lacking TRPM5-MCs, and TRPM5-GFP mice to either vehicle (water) or a mixture of odorous chemicals and chitin for two weeks and analyzed the expression of olfactory signaling proteins using immunolabeling and neurotrophin (NT) and NT receptor (NTR) gene transcripts using real-time quantitative PCR. The chemical exposure did not significantly attenuate the immunolabeling of olfactory signaling proteins. Vehicle-exposed Skn-1a-/- and TRPM5-GFP mice expressed similar levels of NT and NTR gene transcripts in the MOE and olfactory bulb. Chemical exposure significantly increased MOE expression of p75NTR in Skn-1a-/- mice, while p75NTR expression was reduced in TRPM5-GFP mice, as compared to vehicle-exposed mice. Additionally, our RNA in situ hybridization analysis and immunolabeling confirmed MOE expression of most NTs and NTRs. Together, these results indicate that TRPM5-MCs and chemical exposure influence expression of some NTs and NTRs in the MOE and olfactory bulb (OB).
Collapse
Affiliation(s)
- Abdullah AlMatrouk
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD 21250, USA.
| | - Kayla Lemons
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD 21250, USA.
| | - Tatsuya Ogura
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD 21250, USA.
| | - Wangmei Luo
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD 21250, USA.
| | - Chantel Wilson
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD 21250, USA.
| | - Weihong Lin
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD 21250, USA.
| |
Collapse
|
8
|
Kharade SS, Parekh VI, Agarwal SK. Functional Defects From Endocrine Disease-Associated Mutations in HLXB9 and Its Interacting Partner, NONO. Endocrinology 2018; 159:1199-1212. [PMID: 29309627 PMCID: PMC5793795 DOI: 10.1210/en.2017-03155] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 12/28/2017] [Indexed: 12/31/2022]
Abstract
The insulin-secreting pancreatic neuroendocrine tumors, insulinomas, characterized by increased pancreatic islet β-cell proliferation, express the phosphorylated isoform of the β-cell differentiation factor HLXB9 that interacts with NONO/p54NRB, a survival factor. Interestingly, two different homozygous germline mutations in HLXB9, p.F248L and p.F272L, were reported in neonatal diabetes, a condition with functional β-cell deficiency. Also, two somatic heterozygous NONO mutations were found in endocrine-related tumors, p.H146R (parathyroid) and p.R293H (small intestine neuroendocrine tumor). However, the biological consequence of the mutations, and the role of HLXB9-NONO interaction in normal or abnormal β cells, is not known. Expression, localization, and functional analysis of the clinically relevant HLXB9 and NONO mutants showed that HLXB9/p.F248L mutant localized in the nucleus but lacked phosphorylation, and NONO/p.R293H mutant was structurally impaired. The HLXB9 and NONO mutants retained the ability to interact, and overexpression of wild-type or mutant HXLB9 in MIN6 cells suppressed cell proliferation. To further understand the biological consequence of the HLXB9-NONO interaction, we mapped the NONO-interacting region in HLXB9. An 80-amino acid conserved region of HLXB9 could compete with full-length HLXB9 to interact with NONO; however, in functional assays, nuclear expression of this HLXB9-conserved region in MIN6 cells did not interfere with cell proliferation. Overall, our results highlight the importance of HLXB9 in conditions of β-cell excess (insulinomas) and in conditions of β-cell loss or dysfunction (diabetes). Our studies implicate therapeutic strategies for either reducing β-cell proliferation in insulinomas or alleviating normal β-cell deficiency in diabetes through the modulation of HLXB9 phosphorylation.
Collapse
Affiliation(s)
- Sampada S. Kharade
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892
| | - Vaishali I. Parekh
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892
| | - Sunita K. Agarwal
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892
| |
Collapse
|
9
|
Pham DH, Tan CC, Homan CC, Kolc KL, Corbett MA, McAninch D, Fox AH, Thomas PQ, Kumar R, Gecz J. Protocadherin 19 (PCDH19) interacts with paraspeckle protein NONO to co-regulate gene expression with estrogen receptor alpha (ERα). Hum Mol Genet 2017; 26:2042-2052. [PMID: 28334947 PMCID: PMC5437529 DOI: 10.1093/hmg/ddx094] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 03/08/2017] [Indexed: 11/12/2022] Open
Abstract
De novo and inherited mutations of X-chromosome cell adhesion molecule protocadherin 19 (PCDH19) cause frequent, highly variable epilepsy, autism, cognitive decline and behavioural problems syndrome. Intriguingly, hemizygous null males are not affected while heterozygous females are, contradicting established X-chromosome inheritance. The disease mechanism is not known. Cellular mosaicism is the likely driver. We have identified p54nrb/NONO, a multifunctional nuclear paraspeckle protein with known roles in nuclear hormone receptor gene regulation, as a PCDH19 protein interacting partner. Using breast cancer cells we show that PCDH19-NONO complex is a positive co-regulator of ERα-mediated gene expression. Expression of mutant PCDH19 affects at least a subset of known ERα-regulated genes. These data are consistent with our findings that genes regulated by nuclear hormone receptors and those involved in the metabolism of neurosteroids in particular are dysregulated in PCDH19-epilepsy girls and affected mosaic males. Overall we define and characterize a novel mechanism of gene regulation driven by PCDH19, which is mediated by paraspeckle constituent NONO and is ERα-dependent. This PCDH19-NONO-ERα axis is of relevance not only to PCDH19-epilepsy and its comorbidities but likely also to ERα and generally nuclear hormone receptor-associated cancers.
Collapse
Affiliation(s)
- Duyen H. Pham
- Adelaide Medical School, The University of Adelaide, Adelaide 5000, Australia
- Robinson Research Institute, The University of Adelaide, Adelaide 5006, Australia
| | - Chuan C. Tan
- Adelaide Medical School, The University of Adelaide, Adelaide 5000, Australia
| | - Claire C. Homan
- School of Biological Sciences, The University of Adelaide, Adelaide 5000, Australia
| | - Kristy L. Kolc
- Adelaide Medical School, The University of Adelaide, Adelaide 5000, Australia
- Robinson Research Institute, The University of Adelaide, Adelaide 5006, Australia
| | - Mark A. Corbett
- Adelaide Medical School, The University of Adelaide, Adelaide 5000, Australia
- Robinson Research Institute, The University of Adelaide, Adelaide 5006, Australia
| | - Dale McAninch
- School of Biological Sciences, The University of Adelaide, Adelaide 5000, Australia
| | - Archa H. Fox
- School of Human Sciences and School of Molecular Sciences, University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009 and Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, WA, 6009, Australia
| | - Paul Q. Thomas
- School of Biological Sciences, The University of Adelaide, Adelaide 5000, Australia
| | - Raman Kumar
- Adelaide Medical School, The University of Adelaide, Adelaide 5000, Australia
- Robinson Research Institute, The University of Adelaide, Adelaide 5006, Australia
| | - Jozef Gecz
- Adelaide Medical School, The University of Adelaide, Adelaide 5000, Australia
- Robinson Research Institute, The University of Adelaide, Adelaide 5006, Australia
- School of Biological Sciences, The University of Adelaide, Adelaide 5000, Australia
- South Australian Health and Medical Research Institute, Adelaide 5000, Australia
- To whom correspondence should be addressed. Tel: +61 883133245; Fax: +61 881617342;
| |
Collapse
|
10
|
Maeda N, Narukawa M, Ishimaru Y, Yamamoto K, Misaka T, Abe K. A large increase of sour taste receptor cells in Skn-1-deficient mice does not alter the number of their sour taste signal-transmitting gustatory neurons. Neurosci Lett 2017; 648:53-58. [PMID: 28359935 DOI: 10.1016/j.neulet.2017.03.046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 03/01/2017] [Accepted: 03/26/2017] [Indexed: 11/19/2022]
Abstract
The connections between taste receptor cells (TRCs) and innervating gustatory neurons are formed in a mutually dependent manner during development. To investigate whether a change in the ratio of cell types that compose taste buds influences the number of innervating gustatory neurons, we analyzed the proportion of gustatory neurons that transmit sour taste signals in adult Skn-1a-/- mice in which the number of sour TRCs is greatly increased. We generated polycystic kidney disease 1 like 3-wheat germ agglutinin (pkd1l3-WGA)/Skn-1a+/+ and pkd1l3-WGA/Skn-1a-/- mice by crossing Skn-1a-/- mice and pkd1l3-WGA transgenic mice, in which neural pathways of sour taste signals can be visualized. The number of WGA-positive cells in the circumvallate papillae is 3-fold higher in taste buds of pkd1l3-WGA/Skn-1a-/- mice relative to pkd1l3-WGA/Skn-1a+/+ mice. Intriguingly, the ratio of WGA-positive neurons to P2X2-expressing gustatory neurons in nodose/petrosal ganglia was similar between pkd1l3-WGA/Skn-1a+/+ and pkd1l3-WGA/Skn-1a-/- mice. In conclusion, an alteration in the ratio of cell types that compose taste buds does not influence the number of gustatory neurons that transmit sour taste signals.
Collapse
Affiliation(s)
- Naohiro Maeda
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Masataka Narukawa
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Yoshiro Ishimaru
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan; Department of Agricultural Chemistry, Faculty of Agriculture, Meiji University, Tama-ku, Kawasaki-shi, Kanagawa, Japan
| | - Kurumi Yamamoto
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Takumi Misaka
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Keiko Abe
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan; Kanagawa Academy of Science and Technology, Takatsu-ku, Kawasaki-shi, Kanagawa, Japan.
| |
Collapse
|
11
|
Chowdhury S, Yung E, Pintilie M, Muaddi H, Chaib S, Yeung M, Fusciello M, Sykes J, Pitcher B, Hagenkort A, McKee T, Vellanki R, Chen E, Bristow RG, Wouters BG, Koritzinsky M. MATE2 Expression Is Associated with Cancer Cell Response to Metformin. PLoS One 2016; 11:e0165214. [PMID: 27959931 PMCID: PMC5154501 DOI: 10.1371/journal.pone.0165214] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 09/16/2016] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND There is great interest in repurposing the commonly prescribed anti-diabetic drug metformin for cancer therapy. Intracellular uptake and retention of metformin is affected by the expression of organic cation transporters (OCT) 1-3 and by multidrug and toxic compound extrusion (MATE) 1-2. Inside cells, metformin inhibits mitochondrial function, which leads to reduced oxygen consumption and inhibition of proliferation. Reduced oxygen consumption can lead to improved tumor oxygenation and radiation response. PURPOSE Here we sought to determine if there is an association between the effects of metformin on inhibiting oxygen consumption, proliferation and expression of OCTs and MATEs in a panel of 19 cancer cell lines. RESULTS There was relatively large variability in the anti-proliferative response of different cell lines to metformin, with a subset of cell lines being very resistant. In contrast, all cell lines demonstrated sensitivity to the inhibition of oxygen consumption by metformin, with relatively small variation. The expression of OCT1 correlated with expression of both OCT2 and OCT3. OCT1 and OCT2 were relatively uniformly expressed, whereas expression of OCT3, MATE1 and MATE2 showed substantial variation across lines. There were statistically significant associations between resistance to inhibition of proliferation and MATE2 expression, as well as between sensitivity to inhibition of oxygen consumption and OCT3 expression. One cell line (LNCaP) with high OCT3 and low MATE2 expression in concert, had substantially higher intracellular metformin concentration than other cell lines, and was exquisitely sensitive to both anti-proliferative and anti-respiratory effects. In all other cell lines, the concentration of metformin required to inhibit oxygen consumption acutely in vitro was substantially higher than that achieved in the plasma of diabetic patients. However, administering anti-diabetic doses of metformin to tumor-bearing mice resulted in intratumoral accumulation of metformin and reduced hypoxic tumor fractions. CONCLUSIONS All cancer cells are susceptible to inhibition of oxygen consumption by metformin, which results in reduced hypoxic tumor fractions beneficial for the response to radiotherapy. High MATE2 expression may result in resistance to the anti-proliferative effect of metformin and should be considered as a negative predictive biomarker in clinical trials.
Collapse
Affiliation(s)
- Sanjana Chowdhury
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
- Institute of Medical Science, University of Toronto, Toronto, Canada
| | - Eric Yung
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
- Institute of Medical Science, University of Toronto, Toronto, Canada
| | - Melania Pintilie
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
| | - Hala Muaddi
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
- Institute of Medical Science, University of Toronto, Toronto, Canada
| | - Selim Chaib
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
- University of Maastricht, Maastricht, The Netherlands
| | - ManTek Yeung
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
| | - Manlio Fusciello
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
- University of Maastricht, Maastricht, The Netherlands
| | - Jenna Sykes
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
| | - Bethany Pitcher
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
| | - Anna Hagenkort
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
- University of Maastricht, Maastricht, The Netherlands
| | - Trevor McKee
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
| | - Ravi Vellanki
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
| | - Eric Chen
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
| | - Robert G. Bristow
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
- Institute of Medical Science, University of Toronto, Toronto, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
- Department of Radiation Oncology, University of Toronto, Toronto, Canada
| | - Bradly G. Wouters
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
- University of Maastricht, Maastricht, The Netherlands
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
- Department of Radiation Oncology, University of Toronto, Toronto, Canada
| | - Marianne Koritzinsky
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
- Institute of Medical Science, University of Toronto, Toronto, Canada
- Department of Radiation Oncology, University of Toronto, Toronto, Canada
- * E-mail:
| |
Collapse
|
12
|
Ushiama S, Ishimaru Y, Narukawa M, Yoshioka M, Kozuka C, Watanabe N, Tsunoda M, Osakabe N, Asakura T, Masuzaki H, Abe K. Catecholamines Facilitate Fuel Expenditure and Protect Against Obesity via a Novel Network of the Gut-Brain Axis in Transcription Factor Skn-1-deficient Mice. EBioMedicine 2016; 8:60-71. [PMID: 27428419 PMCID: PMC4919597 DOI: 10.1016/j.ebiom.2016.04.031] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 04/23/2016] [Accepted: 04/25/2016] [Indexed: 11/26/2022] Open
Abstract
Taste signals and nutrient stimuli sensed by the gastrointestinal tract are transmitted to the brain to regulate feeding behavior and energy homeostasis. This system is referred to as the gut-brain axis. Here we show that both brush cells and type II taste cells are eliminated in the gastrointestinal tract of transcription factor Skn-1 knockout (KO) mice. Despite unaltered food intake, Skn-1 KO mice have reduced body weight with lower body fat due to increased energy expenditure. In this model, 24-h urinary excretion of catecholamines was significantly elevated, accompanied by increased fatty acid β-oxidation and fuel dissipation in skeletal muscle and impaired insulin secretion driven by glucose. These results suggest the existence of brain-mediated energy homeostatic pathways originating from brush cells and type II taste cells in the gastrointestinal tract and ending in peripheral tissues, including the adrenal glands. The discovery of food-derived factors that regulate these cells may open new avenues the treatment of obesity and diabetes. RESEARCH CONTEXT Taste signals and nutrient stimuli sensed by the gastrointestinal tract are transmitted to the brain to regulate feeding behavior and energy homeostasis along the gut-brain axis. We propose the concept that taste-receiving cells in the oral cavity and/or food-borne chemicals-receiving brush cells in the gut are involved in regulation of the body weight and adiposity via the brain. The discovery of food-derived factors that regulate these cells may open new avenues for the treatment of obesity and diabetes.
Collapse
Affiliation(s)
- Shota Ushiama
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yoshiro Ishimaru
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
| | - Masataka Narukawa
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Misako Yoshioka
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Chisayo Kozuka
- Division of Endocrinology, Diabetes and Metabolism, Hematology, Rheumatology (Second Department of Internal Medicine), Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa 903-0215, Japan
| | - Naoki Watanabe
- Department of Bio-science and Engineering, Shibaura Institute of Technology, 307 Fukasaku, Minuma-ku, Saitama 337-8570, Japan
| | - Makoto Tsunoda
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Naomi Osakabe
- Department of Bio-science and Engineering, Shibaura Institute of Technology, 307 Fukasaku, Minuma-ku, Saitama 337-8570, Japan
| | - Tomiko Asakura
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Hiroaki Masuzaki
- Division of Endocrinology, Diabetes and Metabolism, Hematology, Rheumatology (Second Department of Internal Medicine), Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa 903-0215, Japan
| | - Keiko Abe
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan; Kanagawa Academy of Science and Technology, Takatsu-ku, Kawasaki-shi, Kanagawa, Japan.
| |
Collapse
|
13
|
Mito M, Kawaguchi T, Hirose T, Nakagawa S. Simultaneous multicolor detection of RNA and proteins using super-resolution microscopy. Methods 2015; 98:158-165. [PMID: 26564236 DOI: 10.1016/j.ymeth.2015.11.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2015] [Revised: 11/04/2015] [Accepted: 11/07/2015] [Indexed: 11/19/2022] Open
Abstract
A number of non-membranous cellular bodies have been identified in higher eukaryotes, and these bodies contain a specific set of proteins and RNAs that are used to fulfill their functions. The size of these RNA-containing cellular bodies is usually on a submicron scale, making it difficult to observe fine structures using optical microscopy due to the diffraction limitation of visible light. Recently, microscope companies have released super-resolution microscopes that were developed using different principles, enabling the observation of sub-micron structures not resolvable in conventional fluorescent microscopy. Here, we describe multi-color fluorescent in situ hybridization techniques optimized for the simultaneous detection of RNA and proteins using super-resolution microscopy, namely structured illumination microscopy (SIM).
Collapse
Affiliation(s)
- Mari Mito
- RNA Biology Laboratory, RIKEN, 2-1 Hirosawa, Wako 351-0198, Japan
| | - Tetsuya Kawaguchi
- Institute for Genetic Medicine, Hokkaido University, Sapporo 060-0815, Japan
| | - Tetsuro Hirose
- Institute for Genetic Medicine, Hokkaido University, Sapporo 060-0815, Japan
| | | |
Collapse
|
14
|
Snijders AP, Hautbergue GM, Bloom A, Williamson JC, Minshull TC, Phillips HL, Mihaylov SR, Gjerde DT, Hornby DP, Wilson SA, Hurd PJ, Dickman MJ. Arginine methylation and citrullination of splicing factor proline- and glutamine-rich (SFPQ/PSF) regulates its association with mRNA. RNA 2015; 21:347-59. [PMID: 25605962 PMCID: PMC4338332 DOI: 10.1261/rna.045138.114] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 11/15/2014] [Indexed: 05/19/2023]
Abstract
Splicing factor proline- and glutamine-rich (SFPQ) also commonly known as polypyrimidine tract-binding protein-associated-splicing factor (PSF) and its binding partner non-POU domain-containing octamer-binding protein (NONO/p54nrb), are highly abundant, multifunctional nuclear proteins. However, the exact role of this complex is yet to be determined. Following purification of the endogeneous SFPQ/NONO complex, mass spectrometry analysis identified a wide range of interacting proteins, including those involved in RNA processing, RNA splicing, and transcriptional regulation, consistent with a multifunctional role for SFPQ/NONO. In addition, we have identified several sites of arginine methylation in SFPQ/PSF using mass spectrometry and found that several arginines in the N-terminal domain of SFPQ/PSF are asymmetrically dimethylated. Furthermore, we find that the protein arginine N-methyltransferase, PRMT1, catalyzes this methylation in vitro and that this is antagonized by citrullination of SFPQ. Arginine methylation and citrullination of SFPQ/PSF does not affect complex formation with NONO. However, arginine methylation was shown to increase the association with mRNA in mRNP complexes in mammalian cells. Finally we show that the biochemical properties of the endogenous complex from cell lysates are significantly influenced by the ionic strength during purification. At low ionic strength, the SFPQ/NONO complex forms large heterogeneous protein assemblies or aggregates, preventing the purification of the SFPQ/NONO complex. The ability of the SFPQ/NONO complex to form varying protein assemblies, in conjunction with the effect of post-translational modifications of SFPQ modulating mRNA binding, suggests key roles affecting mRNP dynamics within the cell.
Collapse
Affiliation(s)
- Ambrosius P Snijders
- ChELSI Institute, Chemical and Biological Engineering, University of Sheffield, Sheffield S1 3JD, United Kingdom
| | - Guillaume M Hautbergue
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield S10 2HQ, United Kingdom
| | - Alex Bloom
- Department of Molecular Biology and Biotechnology, Krebs Institute, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - James C Williamson
- ChELSI Institute, Chemical and Biological Engineering, University of Sheffield, Sheffield S1 3JD, United Kingdom
| | - Thomas C Minshull
- ChELSI Institute, Chemical and Biological Engineering, University of Sheffield, Sheffield S1 3JD, United Kingdom
| | - Helen L Phillips
- ChELSI Institute, Chemical and Biological Engineering, University of Sheffield, Sheffield S1 3JD, United Kingdom
| | - Simeon R Mihaylov
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield S10 2HQ, United Kingdom
| | | | - David P Hornby
- Department of Molecular Biology and Biotechnology, Krebs Institute, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Stuart A Wilson
- Department of Molecular Biology and Biotechnology, Krebs Institute, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Paul J Hurd
- School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS, United Kingdom
| | - Mark J Dickman
- ChELSI Institute, Chemical and Biological Engineering, University of Sheffield, Sheffield S1 3JD, United Kingdom
| |
Collapse
|
15
|
Abstract
MIA/CD-RAP is a small, secreted protein involved in cartilage differentiation and melanoma progression. We recently revealed that p54(nrb) acts as a mediator of MIA/CD-RAP action to promote chondrogenesis and the progression of malignant melanoma. As the molecular mechanism of MIA/CD-RAP action in cartilage has not been defined in detail until now, we aimed to understand the regulation of p54(nrb) transcription in chondrogenesis. We concentrated on the previously described MIA/CD-RAP-dependent regulatory region in the p54(nrb) promoter and characterized the transcriptional regulation of p54(nrb) by MIA/CD-RAP in cartilage. A series of truncated p54(nrb) promoter constructs and mutagenesis analysis revealed that the transcription factor YBX1, which has not been investigated in chondrogenesis thus far, is the mediator of MIA/CD-RAP dependent activation of p54(nrb) transcription. A systematic analysis of genes carrying this binding site in their promoter region revealed further potential MIA/CD-RAP-regulated genes that have been implicated in cartilage differentiation. In summary, we described the effects of MIA/CD-RAP on transcriptional regulation in chondrocytes. Understanding the regulation of p54(nrb) via YBX1 contributes to the understanding of chondrogenesis. Uncovering new downstream effectors that function via the activation of YBX1 supports the important role of MIA/CD-RAP in these processes.
Collapse
Affiliation(s)
- Rainer Schmid
- Institute of Pathology, University of Regensburg, Regensburg, Germany
| | - Katharina Meyer
- Institute for Functional Genomics, University of Regensburg, Regensburg, Germany
| | - Rainer Spang
- Institute for Functional Genomics, University of Regensburg, Regensburg, Germany
| | - Birgit Schittek
- Institute of Dermatology, University of Tübingen, Tübingen, Germany
| | | |
Collapse
|
16
|
Keil JM, Liu X, Antonetti DA. Glucocorticoid induction of occludin expression and endothelial barrier requires transcription factor p54 NONO. Invest Ophthalmol Vis Sci 2013; 54:4007-15. [PMID: 23640037 PMCID: PMC3681474 DOI: 10.1167/iovs.13-11980] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 04/26/2013] [Indexed: 12/31/2022] Open
Abstract
PURPOSE Glucocorticoids (GCs) effectively reduce retinal edema and induce vascular barrier properties but possess unwanted side effects. Understanding GC induction of barrier properties may lead to more effective and specific therapies. Previous work identified the occludin enhancer element (OEE) as a GC-responsive cis-element in the promoters of multiple junctional genes, including occludin, claudin-5, and cadherin-9. Here, we identify two OEE-binding factors and determine their contribution to GC induction of tight junction (TJ) gene expression and endothelial barrier properties. METHODS OEE-binding factors were isolated from human retinal endothelial cells (HREC) using DNA affinity purification followed by MALDI-TOF MS/MS. Chromatin immunoprecipitation (ChIP) assays determined in situ binding. siRNA was used to evaluate the role of trans-acting factors in transcription of TJ genes in response to GC stimulation. Paracellular permeability was determined by quantifying flux through a cell monolayer, whereas transendothelial electrical resistance (TER) was measured using the ECIS system. RESULTS MS/MS analysis of HREC nuclear extracts identified the heterodimer of transcription factors p54/NONO (p54) and polypyrimidine tract-binding protein-associated splicing factor (PSF) as OEE-binding factors, which was confirmed by ChIP assay from GC-treated endothelial cells and rat retina. siRNA knockdown of p54 demonstrated that this factor is necessary for GC induction of occludin and claudin-5 expression. Further, p54 knockdown ablated the pro-barrier effects of GC treatment. CONCLUSIONS p54 is essential for GC-mediated expression of occludin, claudin-5, and barrier induction, and the p54/PSF heterodimer may contribute to normal blood-retinal barrier (BRB) induction in vivo. Understanding the mechanism of GC induction of BRB properties may provide novel therapies for macular edema.
Collapse
Affiliation(s)
- Jason M Keil
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, USA
| | | | | |
Collapse
|
17
|
Anchan RM, Quaas P, Gerami-Naini B, Bartake H, Griffin A, Zhou Y, Day D, Eaton JL, George LL, Naber C, Turbe-Doan A, Park PJ, Hornstein MD, Maas RL. Amniocytes can serve a dual function as a source of iPS cells and feeder layers. Hum Mol Genet 2011; 20:962-74. [PMID: 21156717 PMCID: PMC3033187 DOI: 10.1093/hmg/ddq542] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2010] [Revised: 11/17/2010] [Accepted: 12/08/2010] [Indexed: 01/19/2023] Open
Abstract
Clinical barriers to stem-cell therapy include the need for efficient derivation of histocompatible stem cells and the zoonotic risk inherent to human stem-cell xenoculture on mouse feeder cells. We describe a system for efficiently deriving induced pluripotent stem (iPS) cells from human and mouse amniocytes, and for maintaining the pluripotency of these iPS cells on mitotically inactivated feeder layers prepared from the same amniocytes. Both cellular components of this system are thus autologous to a single donor. Moreover, the use of human feeder cells reduces the risk of zoonosis. Generation of iPS cells using retroviral vectors from short- or long-term cultured human and mouse amniocytes using four factors, or two factors in mouse, occurs in 5-7 days with 0.5% efficiency. This efficiency is greater than that reported for mouse and human fibroblasts using similar viral infection approaches, and does not appear to result from selective reprogramming of Oct4(+) or c-Kit(+) amniocyte subpopulations. Derivation of amniocyte-derived iPS (AdiPS) cell colonies, which express pluripotency markers and exhibit appropriate microarray expression and DNA methylation properties, was facilitated by live immunostaining. AdiPS cells also generate embryoid bodies in vitro and teratomas in vivo. Furthermore, mouse and human amniocytes can serve as feeder layers for iPS cells and for mouse and human embryonic stem (ES) cells. Thus, human amniocytes provide an efficient source of autologous iPS cells and, as feeder cells, can also maintain iPS and ES cell pluripotency without the safety concerns associated with xenoculture.
Collapse
Affiliation(s)
- Raymond M. Anchan
- Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology and
| | - Philipp Quaas
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Behzad Gerami-Naini
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Hrishikesh Bartake
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Adam Griffin
- Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology and
| | - Yilan Zhou
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Daniel Day
- Medical Engineering and Medical Physics Graduate Program, Harvard-M.I.T. Division of Health Sciences and Technology, M.I.T., Cambridge, MA 02139, USA and
| | - Jennifer L. Eaton
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Liji L. George
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Catherine Naber
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Annick Turbe-Doan
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Peter J. Park
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
- Children's Hospital Informatics Programand Harvard Medical School, Boston, MA 02115, USA
| | - Mark D. Hornstein
- Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology and
| | - Richard L. Maas
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| |
Collapse
|
18
|
Abstract
Virus-infection of mammalian cells causes transcriptional induction of many cellular genes, collectively called as "viral stress-inducible genes." The proteins encoded by these genes are essential to maintain cell-virus homeostasis, which is required for both virus replication and host survival. Many viral products, including RNA, DNA, and proteins, can induce these genes by using distinct, but partially overlapping, signaling pathways. Type I interferons, direct products of virus infection, can also induce many of these genes, thus providing a positive feedback loop. Double-stranded RNA, a common by-product of virus replication, can induce them by multiple signaling pathways initiated by Toll-like receptor 3 or RIG-I/Mda-5. Several viral stress-inducible proteins inhibit protein synthesis. Proteins of the P56 family bind to the translation initiation factor, eIF-3, and block translation initiation. PKR, a protein kinase, phosphorylates a different initiation factor, eIF-2, and inhibits translation initiation. However, unlike P56, PKR needs to be first activated by dsRNA or PACT, another cellular protein. Another family of enzymes, the 2'-5' oligoadenylate synthetases, synthesizes 2'-5' linked oligoadenylates [2-5(A)] in the presence of dsRNA; 2-5(A) activates the latent ribonuclease, RNase L, which degrades mRNA. Many viruses have evolved mechanisms to evade these genes by blocking their induction or actions; often more than one strategy is used by the same virus to achieve this goal. Thus, in an infected cell, equilibrium is reached between the virus and the cell with regards to the viral stress-inducible genes.
Collapse
Affiliation(s)
- Ganes C Sen
- Department of Molecular Genetics, The Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA
| | | |
Collapse
|
19
|
Kaneko S, Rozenblatt-Rosen O, Meyerson M, Manley JL. The multifunctional protein p54nrb/PSF recruits the exonuclease XRN2 to facilitate pre-mRNA 3' processing and transcription termination. Genes Dev 2007; 21:1779-89. [PMID: 17639083 PMCID: PMC1920172 DOI: 10.1101/gad.1565207] [Citation(s) in RCA: 143] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Termination of RNA polymerase II transcription frequently requires a poly(A) signal and cleavage/polyadenylation factors. Recent work has shown that degradation of the downstream cleaved RNA by the exonuclease XRN2 promotes termination, but how XRN2 functions with 3'-processing factors to elicit termination remains unclear. Here we show that XRN2 physically associates with 3'-processing factors and accumulates at the 3' end of a transcribed gene. In vitro 3'-processing assays show that XRN2 is necessary to degrade the downstream RNA, but is not required for 3' cleavage. Significantly, degradation of the 3'-cleaved RNA was stimulated when coupled to cleavage. Unexpectedly, while investigating how XRN2 is recruited to the 3'-processing machinery, we found that XRN2 associates with p54nrb/NonO(p54)-protein-associated splicing factor (PSF), multifunctional proteins involved in several nuclear processes. Strikingly, p54 is also required for degradation of the 3'-cleaved RNA in vitro. p54 is present along the length of genes, and small interfering RNA (siRNA)-mediated knockdown leads to defects in XRN2 recruitment and termination. Together, our data indicate that p54nrb/PSF functions in recruitment of XRN2 to facilitate pre-mRNA 3' processing and transcription termination.
Collapse
Affiliation(s)
- Syuzo Kaneko
- Department of Biological Sciences, Columbia University, New York, New York, 10027 USA
| | - Orit Rozenblatt-Rosen
- Department of Medical Oncology, Dana-Farber Cancer Institute, and Department of Pathology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Matthew Meyerson
- Department of Medical Oncology, Dana-Farber Cancer Institute, and Department of Pathology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - James L. Manley
- Department of Biological Sciences, Columbia University, New York, New York, 10027 USA
- Corresponding author.E-MAIL ; FAX (212) 865-8246
| |
Collapse
|
20
|
Beck IM, Müller M, Mentlein R, Sadowski T, Mueller MS, Paus R, Sedlacek R. Matrix metalloproteinase-19 expression in keratinocytes is repressed by transcription factors Tst-1 and Skn-1a: implications for keratinocyte differentiation. J Invest Dermatol 2006; 127:1107-14. [PMID: 17195013 DOI: 10.1038/sj.jid.5700674] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Matrix metalloproteinase-19 (MMP-19), unlike other members of the MMP family, is expressed in basal keratinocytes of intact epidermis whereas keratinocytes in suprabasal and higher epidermal layers express this enzyme only during cutaneous disorders. As the activity of MMP-19 effects proliferation, migration, and adhesion of keratinocytes we examined whether transcription factors involved in keratinocyte differentiation repress the expression of MMP-19. Using luciferase reporter assays, POU transcription factors Tst-1 (Oct-6) and Skn-1a (Oct-11) markedly downregulated the activity of MMP-19 promoter in COS-7 cells and HaCaT keratinocytes. Tst-1 alone was able to inhibit 85% of the promoter activity. Skn-1a exhibited a weak inhibitory effect although it synergistically increased effects of Tst-1. HaCaT cells stably transfected with Tst-1 showed a strong decrease of activity of MMP-19 promoter that correlated with suppression of MMP-19, cytokeratin 14 and 5, decreased cell proliferation, and altered expression of involucrin and loricrin. The expression of MMP-9 was also significantly reduced in Tst-1 expressing keratinocytes. MMP-2 was substantially affected during its activation whereas the expression of MMP-28 was unchanged. Our results suggest that Tst-1 and Skn-1a regulate expression of MMPs in keratinocytes and effect both the expression and activation of these proteolytic enzymes.
Collapse
Affiliation(s)
- Inken M Beck
- Institute of Biochemistry, University of Kiel, Kiel, Germany
| | | | | | | | | | | | | |
Collapse
|
21
|
Peterson ML, Bingham GL, Cowan C. Multiple features contribute to the use of the immunoglobulin M secretion-specific poly(A) signal but are not required for developmental regulation. Mol Cell Biol 2006; 26:6762-71. [PMID: 16943419 PMCID: PMC1592873 DOI: 10.1128/mcb.00889-06] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The secretory-specific poly(A) signal (mus) of the immunoglobulin mu gene plays a central role in regulating alternative RNA processing to produce RNAs that encode membrane-associated and secreted immunoglobulins. This poly(A) signal is in direct competition with a splice reaction, and regulation requires that these two reaction efficiencies be balanced. The mus poly(A) signal has several unique sequence features that may contribute to its strength and regulation. Site-directed mutations and small internal deletions made in the intact mu gene show that an extensive AU/A-rich sequence surrounding AAUAAA enhances signal use and that, of the two potential downstream GU-rich elements, both of which appear suboptimally located, only the proximal GU-rich sequence contributes substantially to use of this signal. A GU-rich sequence placed at a more standard location did not improve mus poly(A) signal use. All mu genes tested that contained modified mus poly(A) signals were developmentally regulated, indicating that the GU-rich sequences, the sequences between them previously identified as suboptimal U1A binding sites, and an upstream suboptimal U1A site do not contribute to mu mRNA processing regulation. Expression of wild-type and modified mu genes in HeLa cells overexpressing U1A also failed to demonstrate that U1A contributes to mus poly(A) signal regulation.
Collapse
Affiliation(s)
- Martha L Peterson
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, 800 Rose St., 108A Combs Building, Lexington, KY 40536-0096, USA.
| | | | | |
Collapse
|
22
|
Wu X, Yoo Y, Okuhama NN, Tucker PW, Liu G, Guan JL. Regulation of RNA-polymerase-II-dependent transcription by N-WASP and its nuclear-binding partners. Nat Cell Biol 2006; 8:756-63. [PMID: 16767080 DOI: 10.1038/ncb1433] [Citation(s) in RCA: 142] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2006] [Accepted: 04/24/2006] [Indexed: 12/16/2022]
Abstract
The presence of actin in the nucleus has been well established, and several studies have implicated nuclear actin in transcriptional regulation. Neuronal Wiskott-Aldrich syndrome protein (N-WASP) is a member of the WASP family of proteins; these proteins function in the cytoplasm as key regulators of cortical actin filament. Interestingly, N-WASP has also been observed in the nucleus. However, a potential nuclear function for N-WASP has not been established. Here, we report the identification of nuclear N-WASP within a large nuclear-protein complex containing PSF-NonO (polypyrimidine-tract-binding-protein-associated splicing factor-non-Pou-domain octamer-binding protein/p54(nrb)), nuclear actin and RNA polymerase II. The PSF-NonO complex is involved in the regulation of many cellular processes, such as transcription, RNA processing, DNA unwinding and repair. We demonstrate that the interaction of N-WASP with the PSF-NonO complex can couple N-WASP with RNA polymerase II to regulate transcription. We also provide evidence that the potential function of N-WASP in promoting polymerization of nuclear actins has an important role in this process. Based on these results, we propose a nuclear function for N-WASP in transcriptional regulation.
Collapse
Affiliation(s)
- Xiaoyang Wu
- Department of Molecular Medicine, Cornell University, Ithaca, NY 14853, USA
| | | | | | | | | | | |
Collapse
|
23
|
Abstract
Oct-1 and Oct-2 are members of the POU homeodomain family of transcriptional regulators and are critical for normal embryonic development. Gene-targeting studies showed that Oct-1 and Oct-2 are largely dispensable for B-cell development and immunoglobulin production, although both Oct-2 and Bob-1 are required for a proper immune response and germinal center formation. In these studies, we investigated the role of Oct factors in B-cell lymphomas. Recent investigations have shown increased expression of Oct-2 and Bob-1 in lymphomas, and we observed greatly increased levels of Oct-2 in lymphoma cells with the t(14;18) translocation. Decreased expression of Oct-1, Oct-2, or Bob-1 by RNA interference resulted in apoptosis and down-regulation of bcl-2 expression. Furthermore, Oct-2 induced bcl-2 promoter activity and mediated this effect through three regions in the bcl-2 P2 promoter. Although these regions did not contain canonical octamer motifs, we observed the direct interaction of Oct-2 with all three sites both in vitro by EMSA and in vivo by chromatin immunoprecipitation assay. Moreover, by mutation analysis we found that the ability of Oct-2 to activate bcl-2 required C/EBP, Cdx, and TATA-binding sites. Oct-2, therefore, acts as a cell survival factor in t(14;18) lymphoma cells by directly activating the antiapoptotic gene bcl-2.
Collapse
Affiliation(s)
- C A Heckman
- Center for Molecular Biology in Medicine, Palo Alto VAHCS, Palo Alto, CA, USA
| | | | | | | |
Collapse
|