1
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Nuttle X, Burt ND, Currall B, Moysés-Oliveira M, Mohajeri K, Bhavsar R, Lucente D, Yadav R, Tai DJC, Gusella JF, Talkowski ME. Parallelized engineering of mutational models using piggyBac transposon delivery of CRISPR libraries. CELL REPORTS METHODS 2024; 4:100672. [PMID: 38091988 PMCID: PMC10831954 DOI: 10.1016/j.crmeth.2023.100672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 08/14/2023] [Accepted: 11/21/2023] [Indexed: 01/25/2024]
Abstract
New technologies and large-cohort studies have enabled novel variant discovery and association at unprecedented scale, yet functional characterization of these variants remains paramount to deciphering disease mechanisms. Approaches that facilitate parallelized genome editing of cells of interest or induced pluripotent stem cells (iPSCs) have become critical tools toward this goal. Here, we developed an approach that incorporates libraries of CRISPR-Cas9 guide RNAs (gRNAs) together with inducible Cas9 into a piggyBac (PB) transposon system to engineer dozens to hundreds of genomic variants in parallel against isogenic cellular backgrounds. This method empowers loss-of-function (LoF) studies through the introduction of insertions or deletions (indels) and copy-number variants (CNVs), though generating specific nucleotide changes is possible with prime editing. The ability to rapidly establish high-quality mutational models at scale will facilitate the development of isogenic cellular collections and catalyze comparative functional genomic studies investigating the roles of hundreds of genes and mutations in development and disease.
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Affiliation(s)
- Xander Nuttle
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital, Boston, MA, USA; Department of Neurology, Harvard Medical School, Boston, MA, USA; Stanley Center for Psychiatric Research, Broad Institute, Cambridge, MA, USA; Program in Medical and Population Genetics, Broad Institute, Cambridge, MA, USA.
| | - Nicholas D Burt
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Benjamin Currall
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Mariana Moysés-Oliveira
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital, Boston, MA, USA; Department of Neurology, Harvard Medical School, Boston, MA, USA; Stanley Center for Psychiatric Research, Broad Institute, Cambridge, MA, USA; Program in Medical and Population Genetics, Broad Institute, Cambridge, MA, USA
| | - Kiana Mohajeri
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital, Boston, MA, USA; Stanley Center for Psychiatric Research, Broad Institute, Cambridge, MA, USA; Program in Medical and Population Genetics, Broad Institute, Cambridge, MA, USA; PhD program in Biological and Biomedical Sciences, Harvard Medical School, Boston, MA, USA
| | - Riya Bhavsar
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital, Boston, MA, USA; Department of Neurology, Harvard Medical School, Boston, MA, USA; Stanley Center for Psychiatric Research, Broad Institute, Cambridge, MA, USA; Program in Medical and Population Genetics, Broad Institute, Cambridge, MA, USA
| | - Diane Lucente
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Rachita Yadav
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital, Boston, MA, USA; Department of Neurology, Harvard Medical School, Boston, MA, USA; Stanley Center for Psychiatric Research, Broad Institute, Cambridge, MA, USA; Program in Medical and Population Genetics, Broad Institute, Cambridge, MA, USA
| | - Derek J C Tai
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital, Boston, MA, USA; Department of Neurology, Harvard Medical School, Boston, MA, USA; Stanley Center for Psychiatric Research, Broad Institute, Cambridge, MA, USA; Program in Medical and Population Genetics, Broad Institute, Cambridge, MA, USA
| | - James F Gusella
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital, Boston, MA, USA; Program in Medical and Population Genetics, Broad Institute, Cambridge, MA, USA; Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA; Harvard Stem Cell Institute, Cambridge, MA, USA
| | - Michael E Talkowski
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital, Boston, MA, USA; Department of Neurology, Harvard Medical School, Boston, MA, USA; Stanley Center for Psychiatric Research, Broad Institute, Cambridge, MA, USA; Program in Medical and Population Genetics, Broad Institute, Cambridge, MA, USA.
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2
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Muto V, Benigni F, Magliocca V, Borghi R, Flex E, Pallottini V, Rosa A, Compagnucci C, Tartaglia M. CRISPR/Cas9 and piggyBac Transposon-Based Conversion of a Pathogenic Biallelic TBCD Variant in a Patient-Derived iPSC Line Allows Correction of PEBAT-Related Endophenotypes. Int J Mol Sci 2023; 24:ijms24097988. [PMID: 37175696 PMCID: PMC10178052 DOI: 10.3390/ijms24097988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 04/20/2023] [Accepted: 04/21/2023] [Indexed: 05/15/2023] Open
Abstract
Induced pluripotent stem cells (iPSCs) have been established as a reliable in vitro disease model system and represent a particularly informative tool when animal models are not available or do not recapitulate the human pathophenotype. The recognized limit in using this technology is linked to some degree of variability in the behavior of the individual patient-derived clones. The development of CRISPR/Cas9-based gene editing solves this drawback by obtaining isogenic iPSCs in which the genetic lesion is corrected, allowing a straightforward comparison with the parental patient-derived iPSC lines. Here, we report the generation of a footprint-free isogenic cell line of patient-derived TBCD-mutated iPSCs edited using the CRISPR/Cas9 and piggyBac technologies. The corrected iPSC line had no genetic footprint after the removal of the selection cassette and maintained its "stemness". The correction of the disease-causing TBCD missense substitution restored proper protein levels of the chaperone and mitotic spindle organization, as well as reduced cellular death, which were used as read-outs of the TBCD KO-related endophenotype. The generated line represents an informative in vitro model to understand the impact of pathogenic TBCD mutations on nervous system development and physiology.
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Affiliation(s)
- Valentina Muto
- Molecular Genetics and Functional Genomics, Ospedale Pediatrico Bambino Gesù, IRCCS, 00146 Rome, Italy
| | - Federica Benigni
- Molecular Genetics and Functional Genomics, Ospedale Pediatrico Bambino Gesù, IRCCS, 00146 Rome, Italy
- Department of Science, University Roma Tre, 00146 Rome, Italy
| | - Valentina Magliocca
- Molecular Genetics and Functional Genomics, Ospedale Pediatrico Bambino Gesù, IRCCS, 00146 Rome, Italy
| | - Rossella Borghi
- Molecular Genetics and Functional Genomics, Ospedale Pediatrico Bambino Gesù, IRCCS, 00146 Rome, Italy
| | - Elisabetta Flex
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, 00161 Rome, Italy
| | - Valentina Pallottini
- Department of Science, University Roma Tre, 00146 Rome, Italy
- Neuroendocrinology Metabolism and Neuropharmacology Unit, IRCSS Fondazione Santa Lucia, 00143 Rome, Italy
| | - Alessandro Rosa
- Department of Biology and Biotechnologies "Charles Darwin", Sapienza University of Rome, 00185 Rome, Italy
- Center for Life Nano- & Neuro-Science, Fondazione Istituto Italiano di Tecnologia (IIT), 00161 Rome, Italy
| | - Claudia Compagnucci
- Molecular Genetics and Functional Genomics, Ospedale Pediatrico Bambino Gesù, IRCCS, 00146 Rome, Italy
| | - Marco Tartaglia
- Molecular Genetics and Functional Genomics, Ospedale Pediatrico Bambino Gesù, IRCCS, 00146 Rome, Italy
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3
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Wan L, Hu X, Xia T, Li F, Chi Q, Ma H, Yan S, Li W, Huang W. Disruption of Cdyl gene impairs mouse lung epithelium differentiation and maturation. Gene 2023; 853:147088. [PMID: 36464171 DOI: 10.1016/j.gene.2022.147088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Revised: 11/08/2022] [Accepted: 11/28/2022] [Indexed: 12/03/2022]
Abstract
CDYL is a chromodomain protein that has been identified as a transcriptional co-repressor that is primarily involved in the formation of repressor complexes which coordinate histone modifications to repress gene transcription. However, most functions and mechanisms of action of the CDYL protein are unknown. In this study, we show that Cdyl-/- mice died of respiratory distress immediately at birth because of distinct abnormalities in distal lung morphogenesis which was characterized by thickened septal and expiratory alveolus atelectasis. Furthermore, Cdyl deletion in mice led to excessive proliferation of immature epithelial cells and an arrest in alveolar epithelium cell differentiation in late gestation which were associated with decreased secretion of mature surfactant proteins in alveolus. Microarray analysis showed that Cdyl gene deletion influenced the expression of genes regulating neuroactive ligand-receptor interactions, cell adhesion, and cell cycle. We validated that Cdyl repressed the transcriptional activity of Cks1 in vitro. In conclusion, Cdyl gene participates in the perinatal respiratory epithelium differentiation and maturation that is important for normal lung function at birth.
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Affiliation(s)
- Li Wan
- Clinical Laboratory, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou 510260, China; Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Xiaojun Hu
- Center for Interventional Medicine, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, China
| | - Tian Xia
- Department of Hematology and Oncology, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou 310005, China
| | - Fugui Li
- Cancer Research Institute of Zhongshan City, Zhongshan City People's Hospital, Zhongshan 528403, China
| | - Qiong Chi
- Clinical Laboratory, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou 510260, China
| | - Hongmei Ma
- Clinical Laboratory, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou 510260, China
| | - Sunxing Yan
- Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Weiqiang Li
- Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Weijun Huang
- Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.
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4
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Suzuki S, Chosa K, Barillà C, Yao M, Zuffardi O, Kai H, Shuto T, Suico MA, Kan YW, Sargent RG, Gruenert DC. Seamless Gene Correction in the Human Cystic Fibrosis Transmembrane Conductance Regulator Locus by Vector Replacement and Vector Insertion Events. Front Genome Ed 2022; 4:843885. [PMID: 35465025 PMCID: PMC9019469 DOI: 10.3389/fgeed.2022.843885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 03/07/2022] [Indexed: 11/30/2022] Open
Abstract
Background: Gene correction via homology directed repair (HDR) in patient-derived induced pluripotent stem (iPS) cells for regenerative medicine are becoming a more realistic approach to develop personalized and mutation-specific therapeutic strategies due to current developments in gene editing and iPSC technology. Cystic fibrosis (CF) is the most common inherited disease in the Caucasian population, caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. Since CF causes significant multi-organ damage and with over 2,000 reported CFTR mutations, CF patients could be one prominent population benefiting from gene and cell therapies. When considering gene-editing techniques for clinical applications, seamless gene corrections of the responsible mutations, restoring native "wildtype" DNA sequence without remnants of drug selectable markers or unwanted DNA sequence changes, would be the most desirable approach. Result: The studies reported here describe the seamless correction of the W1282X CFTR mutation using CRISPR/Cas9 nickases (Cas9n) in iPS cells derived from a CF patient homozygous for the W1282X Class I CFTR mutation. In addition to the expected HDR vector replacement product, we discovered another class of HDR products resulting from vector insertion events that created partial duplications of the CFTR exon 23 region. These vector insertion events were removed via intrachromosomal homologous recombination (IHR) enhanced by double nicking with CRISPR/Cas9n which resulted in the seamless correction of CFTR exon 23 in CF-iPS cells. Conclusion: We show here the removal of the drug resistance cassette and generation of seamless gene corrected cell lines by two independent processes: by treatment with the PiggyBac (PB) transposase in vector replacements or by IHR between the tandemly duplicated CFTR gene sequences.
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Affiliation(s)
- Shingo Suzuki
- Department of Otolaryngology–Head and Neck Surgery, University of California, San Francisco, San Francisco, CA, United States
- Department of Medicine, University of California, San Francisco, San Francisco, CA, United States
- Center for Stem Cell and Regenerative Medicine, Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Keisuke Chosa
- Department of Otolaryngology–Head and Neck Surgery, University of California, San Francisco, San Francisco, CA, United States
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan
| | - Cristina Barillà
- Department of Otolaryngology–Head and Neck Surgery, University of California, San Francisco, San Francisco, CA, United States
- Center for Stem Cell and Regenerative Medicine, Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX, United States
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Michael Yao
- Department of Otolaryngology–Head and Neck Surgery, University of California, San Francisco, San Francisco, CA, United States
| | - Orsetta Zuffardi
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Hirofumi Kai
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan
| | - Tsuyoshi Shuto
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan
| | - Mary Ann Suico
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan
| | - Yuet W. Kan
- Department of Medicine, University of California, San Francisco, San Francisco, CA, United States
- Institutes for Human Genetics, University of California, San Francisco, San Francisco, CA, United States
- Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA, United States
| | - R. Geoffrey Sargent
- Department of Otolaryngology–Head and Neck Surgery, University of California, San Francisco, San Francisco, CA, United States
- GeneTether Inc., San Lorenzo, CA, United States
| | - Dieter C. Gruenert
- Department of Otolaryngology–Head and Neck Surgery, University of California, San Francisco, San Francisco, CA, United States
- Institutes for Human Genetics, University of California, San Francisco, San Francisco, CA, United States
- Department of Pediatrics, University of Vermont College of Medicine, Burlington, VT, United States
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5
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Lou Z, Post A, Rodgers CE, Chamankhah M, Hong J, Ahuja CS, Khazaei M, Fehlings MG. Neural Progenitor Cells Expressing Herpes Simplex Virus-Thymidine Kinase for Ablation Have Differential Chemosensitivity to Brivudine and Ganciclovir. Front Cell Neurosci 2021; 15:638021. [PMID: 34938162 PMCID: PMC8685296 DOI: 10.3389/fncel.2021.638021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 11/09/2021] [Indexed: 11/27/2022] Open
Abstract
Neural progenitor cell (NPC) transplants are a promising therapy for treating spinal cord injury (SCI), however, their long-term role after engraftment and the relative contribution to ongoing functional recovery remains a key knowledge gap. Selective human cell ablation techniques, currently being developed to improve the safety of progenitor cell transplant therapies in patients, may also be used as tools to probe the regenerative effects attributable to individual grafted cell populations. The Herpes Simplex Virus Thymidine Kinase (HSV-TK) and ganciclovir (GCV) system has been extensively studied in the context of SCI and broader CNS disease. However, the efficacy of brivudine (BVDU), another HSV-TK prodrug with potentially reduced bystander cytotoxic effects and in vivo toxicity, has yet to be investigated for NPC ablation. In this study, we demonstrate successful generation and in vitro ablation of HSV-TK-expressing human iPSC-derived NPCs with a >80% reduction in survival over controls. We validated an HSV-TK and GCV/BVDU synergistic system with iPSC-NPCs using an efficient gene-transfer method and in vivo ablation in a translationally relevant model of SCI. Our findings demonstrate enhanced ablation efficiency and reduced bystander effects when targeting all rapidly dividing cells with combinatorial GCV and BVDU treatment. However, for use in loss of function studies, BVDU alone is optimal due to reduced nonselective cell ablation.
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Affiliation(s)
- Zijian Lou
- Division of Genetics and Development, Krembil Research Institute, University Health Network, Toronto, ON, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada
| | - Alexander Post
- Division of Genetics and Development, Krembil Research Institute, University Health Network, Toronto, ON, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada
| | - Christopher E Rodgers
- Division of Genetics and Development, Krembil Research Institute, University Health Network, Toronto, ON, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada
| | - Mahmood Chamankhah
- Division of Genetics and Development, Krembil Research Institute, University Health Network, Toronto, ON, Canada
| | - James Hong
- Division of Genetics and Development, Krembil Research Institute, University Health Network, Toronto, ON, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada
| | - Christopher S Ahuja
- Division of Genetics and Development, Krembil Research Institute, University Health Network, Toronto, ON, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada.,Department of Surgery, University of Toronto, Toronto, ON, Canada
| | - Mohamad Khazaei
- Division of Genetics and Development, Krembil Research Institute, University Health Network, Toronto, ON, Canada
| | - Michael G Fehlings
- Division of Genetics and Development, Krembil Research Institute, University Health Network, Toronto, ON, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada.,Department of Surgery, University of Toronto, Toronto, ON, Canada
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6
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Ng D, Zhou M, Zhan D, Yip S, Ko P, Yim M, Modrusan Z, Joly J, Snedecor B, Laird MW, Shen A. Development of a targeted integration Chinese hamster ovary host directly targeting either one or two vectors simultaneously to a single locus using the Cre/Lox recombinase-mediated cassette exchange system. Biotechnol Prog 2021; 37:e3140. [PMID: 33666334 DOI: 10.1002/btpr.3140] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 02/02/2021] [Accepted: 02/14/2021] [Indexed: 12/18/2022]
Abstract
Cell line development (CLD) by random integration (RI) can be labor intensive, inconsistent, and unpredictable due to uncontrolled gene integration after transfection. Unlike RI, targeted integration (TI) based CLD introduces the antibody-expressing cassette to a predetermined site by recombinase-mediated cassette exchange (RMCE). The key to success for the development of a TI host for therapeutic antibody production is to identify a transcriptionally active hotspot that enables highly efficient RMCE and antibody expression with good stability. In this study, a genome wide search for hotspots in the Chinese hamster ovary (CHO)-K1-M genome by either RI or PiggyBac (PB) transposase-based integration has been described. Two CHO-K1-M derived TI host cells were established with the Cre/Lox RMCE system and are described here. Both TI hosts contain a GFP-expressing landing pad flanked by two incompatible LoxP recombination sites (L3 and 2L). In addition, a third incompatible LoxP site (LoxFAS) is inserted in the GFP landing pad to enable an innovative two-plasmid based RMCE strategy, in which two separate vectors can be targeted to a single locus simultaneously. Cell lines generated by the TI system exhibit comparable or higher productivity, better stability and fewer sequence variant (SV) occurrences than the RI cell lines.
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Affiliation(s)
- Domingos Ng
- Department of Cell Culture and Bioprocess Operations, Genentech, Inc., San Francisco, California, USA
| | - Meixia Zhou
- Department of Cell Culture and Bioprocess Operations, Genentech, Inc., San Francisco, California, USA
| | | | - Shirley Yip
- Department of Cell Culture and Bioprocess Operations, Genentech, Inc., San Francisco, California, USA
| | - Peggy Ko
- Department of Cell Culture and Bioprocess Operations, Genentech, Inc., San Francisco, California, USA
| | - Mandy Yim
- Department of Cell Culture and Bioprocess Operations, Genentech, Inc., San Francisco, California, USA
| | - Zora Modrusan
- DNA Sequencing Lab, Genentech, Inc., San Francisco, California, USA
| | - John Joly
- Department of Analytical Development and Quality Control, Genentech, Inc., San Francisco, California, USA
| | - Brad Snedecor
- Department of Cell Culture and Bioprocess Operations, Genentech, Inc., San Francisco, California, USA
| | - Michael W Laird
- Department of Cell Culture and Bioprocess Operations, Genentech, Inc., San Francisco, California, USA
| | - Amy Shen
- Department of Cell Culture and Bioprocess Operations, Genentech, Inc., San Francisco, California, USA
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7
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Marshall P, Garton DR, Taira T, Võikar V, Vilenius C, Kulesskaya N, Rivera C, Andressoo JO. Elevated expression of endogenous glial cell line-derived neurotrophic factor impairs spatial memory performance and raises inhibitory tone in the hippocampus. Eur J Neurosci 2021; 53:2469-2482. [PMID: 33481269 DOI: 10.1111/ejn.15126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 01/07/2021] [Accepted: 01/19/2021] [Indexed: 01/16/2023]
Abstract
Parvalbumin-positive interneurons (PV+) are a key component of inhibitory networks in the brain and are known to modulate memory and learning by shaping network activity. The mechanisms of PV+ neuron generation and maintenance are not fully understood, yet current evidence suggests that signalling via the glial cell line-derived neurotrophic factor (GDNF) receptor GFRα1 positively modulates the migration and differentiation of PV+ interneurons in the cortex. Whether GDNF also regulates PV+ cells in the hippocampus is currently unknown. In this study, we utilized a Gdnf "hypermorph" mouse model where GDNF is overexpressed from the native gene locus, providing greatly increased spatial and temporal specificity of protein expression over established models of ectopic expression. Gdnfwt/hyper mice demonstrated impairments in long-term memory performance in the Morris water maze test and an increase in inhibitory tone in the hippocampus measured electrophysiologically in acute brain slice preparations. Increased PV+ cell number was confirmed immunohistochemically in the hippocampus and in discrete cortical areas and an increase in epileptic seizure threshold was observed in vivo. The data consolidate prior evidence for the actions of GDNF as a regulator of PV+ cell development in the cortex and demonstrate functional effects upon network excitability via modulation of functional GABAergic signalling and under epileptic challenge.
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Affiliation(s)
- Pepin Marshall
- HiLIFE Neuroscience Centre, University of Helsinki, Helsinki, Finland
| | - Daniel R Garton
- Department of Pharmacology, Faculty of Medicine & Helsinki Institute of Life Science (HiLIFE) Helsinki, University of Helsinki, Helsinki, Finland
| | - Tomi Taira
- HiLIFE Neuroscience Centre, University of Helsinki, Helsinki, Finland.,Veterinary Biosciences, University of Helsinki, Helsinki, Finland
| | - Vootele Võikar
- HiLIFE Neuroscience Centre, University of Helsinki, Helsinki, Finland
| | - Carolina Vilenius
- HiLIFE Neuroscience Centre, University of Helsinki, Helsinki, Finland
| | | | - Claudio Rivera
- HiLIFE Neuroscience Centre, University of Helsinki, Helsinki, Finland.,Institut de Neurobiologie de la Méditerranée, INMED UMR901, Marseille, France
| | - Jaan-Olle Andressoo
- Department of Pharmacology, Faculty of Medicine & Helsinki Institute of Life Science (HiLIFE) Helsinki, University of Helsinki, Helsinki, Finland.,Karolinska Institute, Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society (NVS), Stockholm, Sweden
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8
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Trotman JB, Lee DM, Cherney RE, Kim SO, Inoue K, Schertzer MD, Bischoff SR, Cowley DO, Calabrese J. Elements at the 5' end of Xist harbor SPEN-independent transcriptional antiterminator activity. Nucleic Acids Res 2020; 48:10500-10517. [PMID: 32986830 PMCID: PMC7544216 DOI: 10.1093/nar/gkaa789] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 08/20/2020] [Accepted: 09/12/2020] [Indexed: 12/22/2022] Open
Abstract
The Xist lncRNA requires Repeat A, a conserved RNA element located in its 5' end, to induce gene silencing during X-chromosome inactivation. Intriguingly, Repeat A is also required for production of Xist. While silencing by Repeat A requires the protein SPEN, how Repeat A promotes Xist production remains unclear. We report that in mouse embryonic stem cells, expression of a transgene comprising the first two kilobases of Xist (Xist-2kb) causes transcriptional readthrough of downstream polyadenylation sequences. Readthrough required Repeat A and the ∼750 nucleotides downstream, did not require SPEN, and was attenuated by splicing. Despite associating with SPEN and chromatin, Xist-2kb did not robustly silence transcription, whereas a 5.5-kb Xist transgene robustly silenced transcription and read through its polyadenylation sequence. Longer, spliced Xist transgenes also induced robust silencing yet terminated efficiently. Thus, in contexts examined here, Xist requires sequence elements beyond its first two kilobases to robustly silence transcription, and the 5' end of Xist harbors SPEN-independent transcriptional antiterminator activity that can repress proximal cleavage and polyadenylation. In endogenous contexts, this antiterminator activity may help produce full-length Xist RNA while rendering the Xist locus resistant to silencing by the same repressive complexes that the lncRNA recruits to other genes.
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Affiliation(s)
- Jackson B Trotman
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
| | - David M Lee
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
- Curriculum in Genetics and Molecular Biology, Chapel Hill, NC 27599, USA
| | - Rachel E Cherney
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
- Curriculum in Genetics and Molecular Biology, Chapel Hill, NC 27599, USA
| | - Susan O Kim
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
| | - Kaoru Inoue
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
| | - Megan D Schertzer
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
- Curriculum in Genetics and Molecular Biology, Chapel Hill, NC 27599, USA
| | - Steven R Bischoff
- Animal Models Core, University of North Carolina at Chapel Hill, 120 Mason Farm Road, Chapel Hill, NC 27599, USA
| | - Dale O Cowley
- Animal Models Core, University of North Carolina at Chapel Hill, 120 Mason Farm Road, Chapel Hill, NC 27599, USA
| | - J Mauro Calabrese
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
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9
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A versatile toolbox for knock-in gene targeting based on the Multisite Gateway technology. PLoS One 2019; 14:e0221164. [PMID: 31454364 PMCID: PMC6711506 DOI: 10.1371/journal.pone.0221164] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 07/31/2019] [Indexed: 12/20/2022] Open
Abstract
Knock-in (KI) gene targeting can be employed for a wide range of applications in stem cell research. However, vectors for KI require multiple complicated processes for construction, including multiple times of digestion/ligation steps and extensive restriction mapping, which has imposed limitations for the robust applicability of KI gene targeting. To circumvent this issue, here we introduce versatile and systematic methods for generating KI vectors by molecular cloning. In this approach, we employed the Multisite Gateway technology, an efficient in vitro DNA recombination system using proprietary sequences and enzymes. KI vector construction exploiting these methods requires only efficient steps, such as PCR and recombination, enabling robust KI gene targeting. We show that combinatorial usage of the KI vectors generated using this method and site-specific nucleases enabled the precise integration of fluorescent protein genes in multiple loci of human and common marmoset (marmoset; Callithrix jacchus) pluripotent stem cells. The methods described here will facilitate the usage of KI technology and ultimately help to accelerate stem cell research.
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10
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Komatsubara AT, Goto Y, Kondo Y, Matsuda M, Aoki K. Single-cell quantification of the concentrations and dissociation constants of endogenous proteins. J Biol Chem 2019; 294:6062-6072. [PMID: 30739083 DOI: 10.1074/jbc.ra119.007685] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 01/30/2019] [Indexed: 01/23/2023] Open
Abstract
Kinetic simulation is a useful approach for elucidating complex cell-signaling systems. The numerical simulations required for kinetic modeling in live cells critically require parameters such as protein concentrations and dissociation constants (Kd ). However, only a limited number of parameters have been measured experimentally in living cells. Here we describe an approach for quantifying the concentration and Kd of endogenous proteins at the single-cell level with CRISPR/Cas9-mediated knock-in and fluorescence cross-correlation spectroscopy. First, the mEGFP gene was knocked in at the end of the mitogen-activated protein kinase 1 (MAPK1) gene, encoding extracellular signal-regulated kinase 2 (ERK2), through homology-directed repair or microhomology-mediated end joining. Next, the HaloTag gene was knocked in at the end of the ribosomal S6 kinase 2 (RSK2) gene. We then used fluorescence correlation spectroscopy to measure the protein concentrations of endogenous ERK2-mEGFP and RSK2-HaloTag fusion constructs in living cells, revealing substantial heterogeneities. Moreover, fluorescence cross-correlation spectroscopy analyses revealed temporal changes in the apparent Kd values of the binding between ERK2-mEGFP and RSK2-HaloTag in response to epidermal growth factor stimulation. Our approach presented here provides a robust and efficient method for quantifying endogenous protein concentrations and dissociation constants in living cells.
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Affiliation(s)
- Akira T Komatsubara
- From the Laboratory of Bioimaging and Cell Signaling, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan; the Division of Quantitative Biology, National Institute for Basic Biology, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji-cho, Okazaki, Aichi 444-8787, Japan
| | - Yuhei Goto
- the Division of Quantitative Biology, National Institute for Basic Biology, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji-cho, Okazaki, Aichi 444-8787, Japan; the Quantitative Biology Research Group, Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji-cho, Okazaki, Aichi 444-8787, Japan
| | - Yohei Kondo
- the Division of Quantitative Biology, National Institute for Basic Biology, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji-cho, Okazaki, Aichi 444-8787, Japan; the Quantitative Biology Research Group, Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji-cho, Okazaki, Aichi 444-8787, Japan; the Imaging Platform for Spatio-Temporal Information, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan; the Department of Basic Biology, Faculty of Life Science, SOKENDAI (Graduate University for Advanced Studies), Myodaiji, Okazaki, Aichi 444-8787, Japan
| | - Michiyuki Matsuda
- From the Laboratory of Bioimaging and Cell Signaling, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan; the Department of Pathology and Biology of Diseases, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Kazuhiro Aoki
- the Division of Quantitative Biology, National Institute for Basic Biology, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji-cho, Okazaki, Aichi 444-8787, Japan; the Quantitative Biology Research Group, Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji-cho, Okazaki, Aichi 444-8787, Japan; the Imaging Platform for Spatio-Temporal Information, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan; the Department of Basic Biology, Faculty of Life Science, SOKENDAI (Graduate University for Advanced Studies), Myodaiji, Okazaki, Aichi 444-8787, Japan.
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11
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Porokuokka LL, Virtanen HT, Lindén J, Sidorova Y, Danilova T, Lindahl M, Saarma M, Andressoo JO. Gfra1 Underexpression Causes Hirschsprung's Disease and Associated Enterocolitis in Mice. Cell Mol Gastroenterol Hepatol 2018; 7:655-678. [PMID: 30594740 PMCID: PMC6444303 DOI: 10.1016/j.jcmgh.2018.12.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 12/19/2018] [Accepted: 12/19/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS RET, the receptor for the glial cell line-derived neurotrophic factor (GDNF) family ligands, is the most frequently mutated gene in congenital aganglionic megacolon or Hirschsprung's disease (HSCR). The leading cause of mortality in HSCR is HSCR-associated enterocolitis (HAEC), which is characterized by altered mucin composition, mucin retention, bacterial adhesion to enterocytes, and epithelial damage, although the order of these events is obscure. In mice, loss of GDNF signaling leads to a severely underdeveloped enteric nervous system and neonatally fatal kidney agenesis, thereby precluding the use of these mice for modeling postnatal HSCR and HAEC. Our aim was to generate a postnatally viable mouse model for HSCR/HAEC and analyze HAEC etiology. METHODS GDNF family receptor alpha-1 (GFRa1) hypomorphic mice were generated by placing a selectable marker gene in the sixth intron of the Gfra1 locus using gene targeting in mouse embryonic stem cells. RESULTS We report that 70%-80% reduction in GDNF co-receptor GFRa1 expression levels in mice results in HSCR and HAEC, leading to death within the first 25 postnatal days. These mice mirror the disease progression and histopathologic findings in children with untreated HSCR/HAEC. CONCLUSIONS In GFRa1 hypomorphic mice, HAEC proceeds from goblet cell dysplasia, with abnormal mucin production and retention, to epithelial damage. Microbial enterocyte adherence and tissue invasion are late events and therefore unlikely to be the primary cause of HAEC. These results suggest that goblet cells may be a potential target for preventative treatment and that reduced expression of GFRa1 may contribute to HSCR susceptibility.
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Affiliation(s)
| | | | - Jere Lindén
- Department of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Yulia Sidorova
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Tatiana Danilova
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Maria Lindahl
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Mart Saarma
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Jaan-Olle Andressoo
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland,Correspondence Address correspondence to: Jaan-Olle Andressoo, PhD, Department of Pharmacology, Faculty of Medicine, Helsinki Institute of Life Science, University of Helsinki, PO Box 63, 00014 Helsinki, Finland.
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12
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HIV-1 inhibition in cells with CXCR4 mutant genome created by CRISPR-Cas9 and piggyBac recombinant technologies. Sci Rep 2018; 8:8573. [PMID: 29872154 PMCID: PMC5988798 DOI: 10.1038/s41598-018-26894-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 05/22/2018] [Indexed: 01/15/2023] Open
Abstract
The C-X-C chemokine receptor type 4 (CXCR4) is one of the major co-receptors for human immunodeficiency virus type 1 (HIV-1) entry and is considered an important therapeutic target. However, its function in maintaining the development of hematopoietic stem cells (HSC) makes it difficult to be used for HIV-1 gene therapy with HSC transplantation. A previous report showed that the natural CXCR4 P191A mutant inhibits HIV-1 infection without any defect in HSC differentiation, which could provide a basis for the development of new approaches for HIV-1 gene therapy. In the present study, we used CRISPR-Cas9 combined with the piggyBac transposon technologies to efficiently induce the expression of the CXCR4 P191A mutant in an HIV-1 reporter cell line, leading to no detectable exogenous sequences. In addition, no off-target effects were detected in the genome-edited cells. The decline of HIV-1 replication in biallelic CXCR4 gene-edited cells suggests that individuals equipped with homologous recombination of the CXCR4 P191A mutant could prevent or reduce HIV-1 infection. This study provides an effective approach to create a CXCR4 mutation with HIV-1 infection inhibition function and without leaving any genetic footprint inside cells, thereby shedding light on an application in HIV-1 gene therapy and avoiding side effects caused by deficiency or destruction of CXCR4 function.
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13
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Kim SI, Matsumoto T, Kagawa H, Nakamura M, Hirohata R, Ueno A, Ohishi M, Sakuma T, Soga T, Yamamoto T, Woltjen K. Microhomology-assisted scarless genome editing in human iPSCs. Nat Commun 2018; 9:939. [PMID: 29507284 PMCID: PMC5838097 DOI: 10.1038/s41467-018-03044-y] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Accepted: 01/16/2018] [Indexed: 12/26/2022] Open
Abstract
Gene-edited induced pluripotent stem cells (iPSCs) provide relevant isogenic human disease models in patient-specific or healthy genetic backgrounds. Towards this end, gene targeting using antibiotic selection along with engineered point mutations remains a reliable method to enrich edited cells. Nevertheless, integrated selection markers obstruct scarless transgene-free gene editing. Here, we present a method for scarless selection marker excision using engineered microhomology-mediated end joining (MMEJ). By overlapping the homology arms of standard donor vectors, short tandem microhomologies are generated flanking the selection marker. Unique CRISPR-Cas9 protospacer sequences nested between the selection marker and engineered microhomologies are cleaved after gene targeting, engaging MMEJ and scarless excision. Moreover, when point mutations are positioned unilaterally within engineered microhomologies, both mutant and normal isogenic clones are derived simultaneously. The utility and fidelity of our method is demonstrated in human iPSCs by editing the X-linked HPRT1 locus and biallelic modification of the autosomal APRT locus, eliciting disease-relevant metabolic phenotypes.
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Affiliation(s)
- Shin-Il Kim
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, 606-8507, Japan
| | - Tomoko Matsumoto
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, 606-8507, Japan
| | - Harunobu Kagawa
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, 606-8507, Japan
| | - Michiko Nakamura
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, 606-8507, Japan
| | - Ryoko Hirohata
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, 606-8507, Japan
| | - Ayano Ueno
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, 997-0052, Japan
| | - Maki Ohishi
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, 997-0052, Japan
| | - Tetsushi Sakuma
- Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Hiroshima, 739-8526, Japan
| | - Tomoyoshi Soga
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, 997-0052, Japan
| | - Takashi Yamamoto
- Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Hiroshima, 739-8526, Japan
| | - Knut Woltjen
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, 606-8507, Japan. .,Hakubi Center for Advanced Research, Kyoto University, Kyoto, 606-8501, Japan.
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14
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Banno K, Yoder MC. Tissue regeneration using endothelial colony-forming cells: promising cells for vascular repair. Pediatr Res 2018; 83:283-290. [PMID: 28915234 DOI: 10.1038/pr.2017.231] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 07/07/2017] [Indexed: 12/24/2022]
Abstract
Repairing and rebuilding damaged tissue in diseased human subjects remains a daunting challenge for clinical medicine. Proper vascular formation that serves to deliver blood-borne nutrients and adequate levels of oxygen and to remove wastes is critical for successful tissue regeneration. Endothelial colony-forming cells (ECFC) represent a promising cell source for revascularization of damaged tissue. ECFCs are identified by displaying a hierarchy of clonal proliferative potential and by pronounced postnatal vascularization ability in vivo. In this review, we provide a brief overview of human ECFC isolation and characterization, a survey of a number of animal models of human disease in which ECFCs have been shown to have prominent roles in tissue repair, and a summary of current challenges that must be overcome before moving ECFC into human subjects as a cell therapy.
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Affiliation(s)
- Kimihiko Banno
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana
| | - Mervin C Yoder
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana
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15
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Site-specific chromosomal gene insertion: Flp recombinase versus Cas9 nuclease. Sci Rep 2017; 7:17771. [PMID: 29259215 PMCID: PMC5736728 DOI: 10.1038/s41598-017-17651-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 11/24/2017] [Indexed: 12/16/2022] Open
Abstract
Site-specific recombination systems like those based on the Flp recombinase proved themselves as efficient tools for cell line engineering. The recent emergence of designer nucleases, especially RNA guided endonucleases like Cas9, has considerably broadened the available toolbox for applications like targeted transgene insertions. Here we established a recombinase-mediated cassette exchange (RMCE) protocol for the fast and effective, drug-free isolation of recombinant cells. Distinct fluorescent protein patterns identified the recombination status of individual cells. In derivatives of a CHO master cell line the expression of the introduced transgene of interest could be dramatically increased almost 20-fold by subsequent deletion of the fluorescent protein gene that provided the initial isolation principle. The same master cell line was employed in a comparative analysis using CRISPR/Cas9 for transgene integration in identical loci. Even though the overall targeting efficacy was comparable, multi-loci targeting was considerably more effective for Cas9-mediated transgene insertion when compared to RMCE. While Cas9 is inherently more flexible, our results also alert to the risk of aberrant recombination events around the cut site. Together, this study points at the individual strengths in performance of both systems and provides guidance for their appropriate use.
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16
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Shy BR, MacDougall MS, Clarke R, Merrill BJ. Co-incident insertion enables high efficiency genome engineering in mouse embryonic stem cells. Nucleic Acids Res 2016; 44:7997-8010. [PMID: 27484482 PMCID: PMC5027516 DOI: 10.1093/nar/gkw685] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 07/25/2016] [Indexed: 12/26/2022] Open
Abstract
CRISPR/Cas9 nucleases have enabled powerful, new genome editing capabilities; however, the preponderance of non-homologous end joining (NHEJ) mediated repair events over homology directed repair (HDR) in most cell types limits the ability to engineer precise changes in mammalian genomes. Here, we increase the efficiency of isolating precise HDR-mediated events in mouse embryonic stem (ES) cells by more than 20-fold through the use of co-incidental insertion (COIN) of independent donor DNA sequences. Analysis of on:off-target frequencies at the Lef1 gene revealed that bi-allelic insertion of a PGK-Neo cassette occurred more frequently than expected. Using various selection cassettes targeting multiple loci, we show that the insertion of a selectable marker at one control site frequently coincided with an insertion at an unlinked, independently targeted site, suggesting enrichment of a sub-population of HDR-proficient cells. When individual cell events were tracked using flow cytometry and fluorescent protein markers, individual cells frequently performed either a homology-dependent insertion event or a homology-independent event, but rarely both types of insertions in a single cell. Thus, when HDR-dependent selection donors are used, COIN enriches for HDR-proficient cells among heterogeneous cell populations. When combined with a self-excising selection cassette, COIN provides highly efficient and scarless genome editing.
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Affiliation(s)
- Brian R Shy
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, IL 60607, USA Genome Editing Core, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Matthew S MacDougall
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Ryan Clarke
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Bradley J Merrill
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, IL 60607, USA Genome Editing Core, University of Illinois at Chicago, Chicago, IL 60607, USA
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17
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Kumar A, Kopra J, Varendi K, Porokuokka LL, Panhelainen A, Kuure S, Marshall P, Karalija N, Härma MA, Vilenius C, Lilleväli K, Tekko T, Mijatovic J, Pulkkinen N, Jakobson M, Jakobson M, Ola R, Palm E, Lindahl M, Strömberg I, Võikar V, Piepponen TP, Saarma M, Andressoo JO. GDNF Overexpression from the Native Locus Reveals its Role in the Nigrostriatal Dopaminergic System Function. PLoS Genet 2015; 11:e1005710. [PMID: 26681446 PMCID: PMC4682981 DOI: 10.1371/journal.pgen.1005710] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Accepted: 11/06/2015] [Indexed: 12/14/2022] Open
Abstract
Degeneration of nigrostriatal dopaminergic system is the principal lesion in Parkinson’s disease. Because glial cell line-derived neurotrophic factor (GDNF) promotes survival of dopamine neurons in vitro and in vivo, intracranial delivery of GDNF has been attempted for Parkinson’s disease treatment but with variable success. For improving GDNF-based therapies, knowledge on physiological role of endogenous GDNF at the sites of its expression is important. However, due to limitations of existing genetic model systems, such knowledge is scarce. Here, we report that prevention of transcription of Gdnf 3’UTR in Gdnf endogenous locus yields GDNF hypermorphic mice with increased, but spatially unchanged GDNF expression, enabling analysis of postnatal GDNF function. We found that increased level of GDNF in the central nervous system increases the number of adult dopamine neurons in the substantia nigra pars compacta and the number of dopaminergic terminals in the dorsal striatum. At the functional level, GDNF levels increased striatal tissue dopamine levels and augmented striatal dopamine release and re-uptake. In a proteasome inhibitor lactacystin-induced model of Parkinson’s disease GDNF hypermorphic mice were protected from the reduction in striatal dopamine and failure of dopaminergic system function. Importantly, adverse phenotypic effects associated with spatially unregulated GDNF applications were not observed. Enhanced GDNF levels up-regulated striatal dopamine transporter activity by at least five fold resulting in enhanced susceptibility to 6-OHDA, a toxin transported into dopamine neurons by DAT. Further, we report how GDNF levels regulate kidney development and identify microRNAs miR-9, miR-96, miR-133, and miR-146a as negative regulators of GDNF expression via interaction with Gdnf 3’UTR in vitro. Our results reveal the role of GDNF in nigrostriatal dopamine system postnatal development and adult function, and highlight the importance of correct spatial expression of GDNF. Furthermore, our results suggest that 3’UTR targeting may constitute a useful tool in analyzing gene function. Intracranial delivery of GDNF has been attempted for Parkinson’s disease (PD) treatment but with variable success. For improving GDNF-based therapies, knowledge on physiological role of endogenous GDNF at the sites of its expression is important. However, due to limitations of existing genetic model systems, such knowledge is scarce. Here, we utilize an innovative genetic approach by targeting the 3’UTR regulation of Gdnf in mice. Such animals express elevated levels of Gdnf exclusively in natively Gdnf-expressing cells, enabling dissection of endogenous GDNF functions in vivo. We show that endogenous GDNF regulates dopamine system development and function and protects mice in a rodent PD model without side effects associated with ectopic GDNF applications. Further, we report how GDNF levels regulate kidney development and identify microRNAs which control GDNF expression. Our study highlights the importance of correct spatial expression of GDNF and opens a novel approach to study gene function in mice.
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Affiliation(s)
- Anmol Kumar
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Jaakko Kopra
- Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - Kärt Varendi
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | | | - Anne Panhelainen
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Satu Kuure
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Pepin Marshall
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Nina Karalija
- Department of Histology and Cell Biology, Umeå University, Umeå, Sweden
| | - Mari-Anne Härma
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Carolina Vilenius
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Kersti Lilleväli
- Department of Physiology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia
| | - Triin Tekko
- Department of Physiology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia
| | - Jelena Mijatovic
- Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - Nita Pulkkinen
- Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - Madis Jakobson
- Department of Biochemistry and Developmental Biology, Institute of Biomedicine, University of Helsinki, Helsinki, Finland
| | - Maili Jakobson
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Roxana Ola
- Department of Biochemistry and Developmental Biology, Institute of Biomedicine, University of Helsinki, Helsinki, Finland
| | - Erik Palm
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Maria Lindahl
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Ingrid Strömberg
- Department of Histology and Cell Biology, Umeå University, Umeå, Sweden
| | - Vootele Võikar
- Neuroscience Center and Department of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - T. Petteri Piepponen
- Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - Mart Saarma
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Jaan-Olle Andressoo
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
- * E-mail:
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18
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Pur-alpha functionally interacts with FUS carrying ALS-associated mutations. Cell Death Dis 2015; 6:e1943. [PMID: 26492376 PMCID: PMC4632316 DOI: 10.1038/cddis.2015.295] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 08/24/2015] [Indexed: 02/08/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder due to motor neuron loss. Fused in sarcoma (FUS) protein carrying ALS-associated mutations localizes to stress granules and causes their coalescence into larger aggregates. Here we show that Pur-alpha physically interacts with mutated FUS in an RNA-dependent manner. Pur-alpha colocalizes with FUS carrying mutations in stress granules of motoneuronal cells differentiated from induced pluripotent stem cells and that are derived from ALS patients. We observe that both Pur-alpha and mutated FUS upregulate phosphorylation of the translation initiation factor eukaryotic translation initiation factor 2 alpha and consistently inhibit global protein synthesis. In vivo expression of Pur-alpha in different Drosophila tissues significatively exacerbates the neurodegeneration caused by mutated FUS. Conversely, the downregulation of Pur-alpha in neurons expressing mutated FUS significatively improves fly climbing activity. All these findings suggest that Pur-alpha, through the control of mRNA translation, might be involved in the pathogenesis of ALS associated with the mutation of FUS, and that an alteration of protein synthesis may be directly implicated in the disease. Finally, in vivo RNAi-mediated ablation of Pur-alpha produced locomotion defects in Drosophila, indicating a pivotal role for this protein in the motoneuronal function.
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19
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Both TALENs and CRISPR/Cas9 directly target the HBB IVS2-654 (C > T) mutation in β-thalassemia-derived iPSCs. Sci Rep 2015; 5:12065. [PMID: 26156589 PMCID: PMC4496796 DOI: 10.1038/srep12065] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 06/16/2015] [Indexed: 12/19/2022] Open
Abstract
β-Thalassemia is one of the most common genetic blood diseases and is caused by either point mutations or deletions in the β-globin (HBB) gene. The generation of patient-specific induced pluripotent stem cells (iPSCs) and subsequent correction of the disease-causing mutations may be a potential therapeutic strategy for this disease. Due to the low efficiency of typical homologous recombination, endonucleases, including TALENs and CRISPR/Cas9, have been widely used to enhance the gene correction efficiency in patient-derived iPSCs. Here, we designed TALENs and CRISPR/Cas9 to directly target the intron2 mutation site IVS2-654 in the globin gene. We observed different frequencies of double-strand breaks (DSBs) at IVS2-654 loci using TALENs and CRISPR/Cas9, and TALENs mediated a higher homologous gene targeting efficiency compared to CRISPR/Cas9 when combined with the piggyBac transposon donor. In addition, more obvious off-target events were observed for CRISPR/Cas9 compared to TALENs. Finally, TALENs-corrected iPSC clones were selected for erythroblast differentiation using the OP9 co-culture system and detected relatively higher transcription of HBB than the uncorrected cells. This comparison of using TALENs or CRISPR/Cas9 to correct specific HBB mutations in patient-derived iPSCs will guide future applications of TALENs- or CRISPR/Cas9-based gene therapies in monogenic diseases.
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20
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Lenzi J, De Santis R, de Turris V, Morlando M, Laneve P, Calvo A, Caliendo V, Chiò A, Rosa A, Bozzoni I. ALS mutant FUS proteins are recruited into stress granules in induced pluripotent stem cell-derived motoneurons. Dis Model Mech 2015; 8:755-66. [PMID: 26035390 PMCID: PMC4486861 DOI: 10.1242/dmm.020099] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 04/20/2015] [Indexed: 12/13/2022] Open
Abstract
Patient-derived induced pluripotent stem cells (iPSCs) provide an opportunity to study human diseases mainly in those cases for which no suitable model systems are available. Here, we have taken advantage of in vitro iPSCs derived from patients affected by amyotrophic lateral sclerosis (ALS) and carrying mutations in the RNA-binding protein FUS to study the cellular behavior of the mutant proteins in the appropriate genetic background. Moreover, the ability to differentiate iPSCs into spinal cord neural cells provides an in vitro model mimicking the physiological conditions. iPSCs were derived from FUSR514S and FUSR521C patient fibroblasts, whereas in the case of the severe FUSP525L mutation, in which fibroblasts were not available, a heterozygous and a homozygous iPSC line were raised by TALEN-directed mutagenesis. We show that aberrant localization and recruitment of FUS into stress granules (SGs) is a prerogative of the FUS mutant proteins and occurs only upon induction of stress in both undifferentiated iPSCs and spinal cord neural cells. Moreover, we show that the incorporation into SGs is proportional to the amount of cytoplasmic FUS, strongly correlating with the cytoplasmic delocalization phenotype of the different mutants. Therefore, the available iPSCs represent a very powerful system for understanding the correlation between FUS mutations, the molecular mechanisms of SG formation and ALS ethiopathogenesis. Summary: Mutated FUS protein is aberrantly delocalized and recruited into stress granules in iPSC-derived motoneurons, which provide a new model system for amyotrophic lateral sclerosis.
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Affiliation(s)
- Jessica Lenzi
- Center for Life Nano Science, Istituto Italiano di Tecnologia, Viale Regina Elena 291, Rome 00161, Italy Department of Biology and Biotechnology Charles Darwin, Sapienza University of Rome, P.le A. Moro 5, Rome 00185, Italy
| | - Riccardo De Santis
- Center for Life Nano Science, Istituto Italiano di Tecnologia, Viale Regina Elena 291, Rome 00161, Italy Department of Biology and Biotechnology Charles Darwin, Sapienza University of Rome, P.le A. Moro 5, Rome 00185, Italy
| | - Valeria de Turris
- Center for Life Nano Science, Istituto Italiano di Tecnologia, Viale Regina Elena 291, Rome 00161, Italy
| | - Mariangela Morlando
- Department of Biology and Biotechnology Charles Darwin, Sapienza University of Rome, P.le A. Moro 5, Rome 00185, Italy
| | - Pietro Laneve
- Center for Life Nano Science, Istituto Italiano di Tecnologia, Viale Regina Elena 291, Rome 00161, Italy
| | - Andrea Calvo
- Amyotrophic Lateral Sclerosis Center, Rita Levi Montalcini Department of Neuroscience, University of Turin, 10126 Turin, Italy
| | - Virginia Caliendo
- Dermatologia Chirurgica AOU Città della Salute e della Scienza, 10126 Turin, Italy
| | - Adriano Chiò
- Amyotrophic Lateral Sclerosis Center, Rita Levi Montalcini Department of Neuroscience, University of Turin, 10126 Turin, Italy
| | - Alessandro Rosa
- Department of Biology and Biotechnology Charles Darwin, Sapienza University of Rome, P.le A. Moro 5, Rome 00185, Italy
| | - Irene Bozzoni
- Center for Life Nano Science, Istituto Italiano di Tecnologia, Viale Regina Elena 291, Rome 00161, Italy Department of Biology and Biotechnology Charles Darwin, Sapienza University of Rome, P.le A. Moro 5, Rome 00185, Italy Institute Pasteur Fondazione Cenci-Bolognetti, Sapienza University of Rome, P.le A. Moro 5, Rome 00185, Italy
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21
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Xie F, Ye L, Chang JC, Beyer AI, Wang J, Muench MO, Kan YW. Seamless gene correction of β-thalassemia mutations in patient-specific iPSCs using CRISPR/Cas9 and piggyBac. Genome Res 2014; 24:1526-33. [PMID: 25096406 PMCID: PMC4158758 DOI: 10.1101/gr.173427.114] [Citation(s) in RCA: 296] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
β-thalassemia, one of the most common genetic diseases worldwide, is caused by mutations in the human hemoglobin beta (HBB) gene. Creation of human induced pluripotent stem cells (iPSCs) from β-thalassemia patients could offer an approach to cure this disease. Correction of the disease-causing mutations in iPSCs could restore normal function and provide a rich source of cells for transplantation. In this study, we used the latest gene-editing tool, CRISPR/Cas9 technology, combined with the piggyBac transposon to efficiently correct the HBB mutations in patient-derived iPSCs without leaving any residual footprint. No off-target effects were detected in the corrected iPSCs, and the cells retain full pluripotency and exhibit normal karyotypes. When differentiated into erythroblasts using a monolayer culture, gene-corrected iPSCs restored expression of HBB compared to the parental iPSCs line. Our study provides an effective approach to correct HBB mutations without leaving any genetic footprint in patient-derived iPSCs, thereby demonstrating a critical step toward the future application of stem cell-based gene therapy to monogenic diseases.
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Affiliation(s)
- Fei Xie
- Department of Medicine, University of California, San Francisco, California 94143, USA
| | - Lin Ye
- Department of Medicine, University of California, San Francisco, California 94143, USA
| | - Judy C Chang
- Department of Medicine, University of California, San Francisco, California 94143, USA
| | - Ashley I Beyer
- Blood Systems Research Institute, San Francisco, California 94118, USA
| | - Jiaming Wang
- Department of Medicine, University of California, San Francisco, California 94143, USA; Department of Laboratory Medicine, University of California, San Francisco, California 94143, USA
| | - Marcus O Muench
- Blood Systems Research Institute, San Francisco, California 94118, USA; Department of Laboratory Medicine, University of California, San Francisco, California 94143, USA
| | - Yuet Wai Kan
- Department of Medicine, University of California, San Francisco, California 94143, USA; Department of Laboratory Medicine, University of California, San Francisco, California 94143, USA; Institute for Human Genetics, University of California, San Francisco, California 94143, USA
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22
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Morioka Y, Fujihara Y, Okabe M. Generation of precise point mutation mice by footprintless genome modification. Genesis 2013; 52:68-77. [PMID: 24265262 DOI: 10.1002/dvg.22727] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 10/28/2013] [Accepted: 11/09/2013] [Indexed: 11/09/2022]
Abstract
Point mutation mice are a key tool in the study of biological functions of genomic DNA sequences and the creation of human disease models. These mice are produced by homologous recombination combined with site-specific recombinase, which allows removal of drug selection cassettes. However, the methods currently available leave ectopic sequences in the "inactive" intron region of the targeted genome in addition to the desired mutation. Since recent research suggests that the intron region may actually have some functionality, these sequences could potentially interfere with neighboring gene expression and, as a result, affect the mouse phenotype. To completely avoid this issue, we used the PiggyBac transposon to remove selection cassettes and achieve precise genome modification without leaving behind a footprint. This PiggyBac system allowed us to successfully generate mice carrying an artificially introduced W(v) point mutation in the Kit gene, and these mice were confirmed to have phenotypes identical to spontaneous W(v) mutation mice. Generation of W(v) -mutation corrected mice was also possible, and phenotypes were completely restored. Our footprintless genome modification technology can generate precise point mutation mice with only the desired mutation, and they reflect an accurate phenotype that makes these mice a reliable and "worry-free" research resource.
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Affiliation(s)
- Yuka Morioka
- Institute for Genetic Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
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23
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Pettitt SJ, Rehman FL, Bajrami I, Brough R, Wallberg F, Kozarewa I, Fenwick K, Assiotis I, Chen L, Campbell J, Lord CJ, Ashworth A. A genetic screen using the PiggyBac transposon in haploid cells identifies Parp1 as a mediator of olaparib toxicity. PLoS One 2013; 8:e61520. [PMID: 23634208 PMCID: PMC3636235 DOI: 10.1371/journal.pone.0061520] [Citation(s) in RCA: 140] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Accepted: 03/10/2013] [Indexed: 12/23/2022] Open
Abstract
Genetic perturbation screens have the potential to dissect a wide range of cellular phenotypes. Such screens have historically been difficult in diploid mammalian cells. The recent derivation of haploid embryonic stem cells provides an opportunity to cause loss of function mutants with a random mutagen in a mammalian cell with a normal genetic background. We describe an approach to genetic screens that exploits the highly active piggyBac transposon in haploid mammalian cells. As an example of haploid transposon (HTP) screening, we apply this approach to identifying determinants of cancer drug toxicity and resistance. In a screen for 6-thioguanine resistance we recovered components of the DNA mismatch repair pathway, a known requirement for toxicity. In a further screen for resistance to the clinical poly(ADP-ribose) polymerase (PARP) inhibitor olaparib we recovered multiple Parp1 mutants. Our results show that olaparib toxicity to normal cells is mediated predominantly via Parp1, and suggest that the clinical side effects of olaparib may be on target. The transposon mutant libraries are stable and can be readily reused to screen other drugs. The screening protocol described has several advantages over other methods such as RNA interference: it is rapid and low cost, and mutations can be easily reverted to establish causality.
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Affiliation(s)
- Stephen J. Pettitt
- The Breakthrough Breast Cancer Research Centre, The Institute of Cancer Research, London, United Kingdom
- CRUK Gene Function Laboratory, The Institute of Cancer Research, London, United Kingdom
| | - Farah L. Rehman
- The Breakthrough Breast Cancer Research Centre, The Institute of Cancer Research, London, United Kingdom
| | - Ilirjana Bajrami
- The Breakthrough Breast Cancer Research Centre, The Institute of Cancer Research, London, United Kingdom
- CRUK Gene Function Laboratory, The Institute of Cancer Research, London, United Kingdom
| | - Rachel Brough
- The Breakthrough Breast Cancer Research Centre, The Institute of Cancer Research, London, United Kingdom
- CRUK Gene Function Laboratory, The Institute of Cancer Research, London, United Kingdom
| | - Fredrik Wallberg
- The Breakthrough Breast Cancer Research Centre, The Institute of Cancer Research, London, United Kingdom
| | - Iwanka Kozarewa
- Tumour Profiling Unit, The Institute of Cancer Research, London, United Kingdom
| | - Kerry Fenwick
- Tumour Profiling Unit, The Institute of Cancer Research, London, United Kingdom
| | - Ioannis Assiotis
- Tumour Profiling Unit, The Institute of Cancer Research, London, United Kingdom
| | - Lina Chen
- Tumour Profiling Unit, The Institute of Cancer Research, London, United Kingdom
| | - James Campbell
- The Breakthrough Breast Cancer Research Centre, The Institute of Cancer Research, London, United Kingdom
- CRUK Gene Function Laboratory, The Institute of Cancer Research, London, United Kingdom
- Tumour Profiling Unit, The Institute of Cancer Research, London, United Kingdom
| | - Christopher J. Lord
- The Breakthrough Breast Cancer Research Centre, The Institute of Cancer Research, London, United Kingdom
- CRUK Gene Function Laboratory, The Institute of Cancer Research, London, United Kingdom
| | - Alan Ashworth
- The Breakthrough Breast Cancer Research Centre, The Institute of Cancer Research, London, United Kingdom
- CRUK Gene Function Laboratory, The Institute of Cancer Research, London, United Kingdom
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24
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Recombinase-mediated cassette exchange (RMCE) — A rapidly-expanding toolbox for targeted genomic modifications. Gene 2013. [DOI: 10.1016/j.gene.2012.11.016] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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25
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Robker RL, Collins RG, Beaudet AL, Mersmann HJ, Smith CW. Leukocyte Migration in Adipose Tissue of Mice Null for ICAM-1 and Mac-1 Adhesion Receptors. ACTA ACUST UNITED AC 2012; 12:936-40. [PMID: 15229332 DOI: 10.1038/oby.2004.114] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To determine whether the leukocyte adhesion receptors ICAM-1 and Mac-1, regulators of immune cell migration, have an intrinsic role within adipose tissue by 1) analyzing the expression of ICAM-1 in adipose tissue, 2) identifying leukocyte populations within adipose tissue, and 3) determining whether ICAM-1 and Mac-1 mutant mice exhibit abnormal numbers of adipose tissue leukocytes. RESEARCH METHODS AND PROCEDURES Wild-type, ICAM-1(-/-), and Mac-1(-/-) mice were fed a long-term high-fat diet. ICAM-1 expression was analyzed by Northern blot and immunohistochemistry. Leukocytes within adipose tissue were identified by immunohistochemistry and flow cytometry. RESULTS ICAM-1 was expressed in adipose tissue and localized to the vascular endothelium. Macrophages and lymphocytes were prevalent within the stromal-vascular cell fraction of adipose tissue, and gender-specific differences were observed, with adipose tissue from female mice containing significantly more macrophages than tissue from male mice. Numbers of leukocytes in ICAM-1(-/-) and Mac-1(-/-) mice were not different from wild-types, however, indicating that these adhesion receptors are not required for leukocyte migration into adipose tissue. DISCUSSION Our results documented leukocyte populations within adipose tissue, which may be involved in the development of heightened inflammation that is characteristic of obesity.
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Affiliation(s)
- Rebecca L Robker
- Section of Leukocyte Biology, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, 1100 Bates Avenue, Houston, TX 77030, USA
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26
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Abstract
RAD51 is important for restarting stalled replication forks and for repairing DNA double-strand breaks (DSBs) through a pathway called homology-directed repair (HDR). However, analysis of the consequences of specific RAD51 mutants has been difficult since they are toxic. Here we report on the dominant effects of two human RAD51 mutants defective for ATP binding (K133A) or ATP hydrolysis (K133R) expressed in mouse embryonic stem (ES) cells that also expressed normal mouse RAD51 from the other chromosome. These cells were defective for restarting stalled replication forks and repairing breaks. They were also hypersensitive to camptothecin, a genotoxin that generates breaks specifically at the replication fork. In addition, these cells exhibited a wide range of structural chromosomal changes that included multiple breakpoints within the same chromosome. Thus, ATP binding and hydrolysis are essential for chromosomal maintenance. Fusion of RAD51 to a fluorescent tag (enhanced green fluorescent protein [eGFP]) allowed visualization of these proteins at sites of replication and repair. We found very low levels of mutant protein present at these sites compared to normal protein, suggesting that low levels of mutant protein were sufficient for disruption of RAD51 activity and generation of chromosomal rearrangements.
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27
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Arnold K, Sarkar A, Yram MA, Polo JM, Bronson R, Sengupta S, Seandel M, Geijsen N, Hochedlinger K. Sox2(+) adult stem and progenitor cells are important for tissue regeneration and survival of mice. Cell Stem Cell 2012; 9:317-29. [PMID: 21982232 DOI: 10.1016/j.stem.2011.09.001] [Citation(s) in RCA: 583] [Impact Index Per Article: 48.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Revised: 08/05/2011] [Accepted: 09/09/2011] [Indexed: 11/26/2022]
Abstract
The transcription factor Sox2 maintains the pluripotency of early embryonic cells and regulates the formation of several epithelia during fetal development. Whether Sox2 continues to play a role in adult tissues remains largely unknown. We show here that Sox2 marks adult cells in several epithelial tissues where its expression has not previously been characterized, including the stomach, cervix, anus, testes, lens, and multiple glands. Genetic lineage tracing and transplantation experiments demonstrate that Sox2-expressing cells continuously give rise to mature cell types within these tissues, documenting their self-renewal and differentiation potentials. Consistent with these findings, ablation of Sox2(+) cells in mice results in a disruption of epithelial tissue homeostasis and lethality. Developmental fate mapping reveals that Sox2(+) adult stem cells originate from fetal Sox2(+) tissue progenitors. Thus, our results identify Sox2 expression in numerous adult endodermal and ectodermal stem cell compartments, which are critical for normal tissue regeneration and survival.
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Affiliation(s)
- Katrin Arnold
- Howard Hughes Medical Institute and Department of Stem Cell and Regenerative Biology, Harvard University and Harvard Medical School, Cambridge, MA 02138, USA
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28
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Zou C, Chou BK, Dowey SN, Tsang K, Huang X, Liu CF, Smith C, Yen J, Mali P, Zhang YA, Cheng L, Ye Z. Efficient derivation and genetic modifications of human pluripotent stem cells on engineered human feeder cell lines. Stem Cells Dev 2012; 21:2298-311. [PMID: 22225458 DOI: 10.1089/scd.2011.0688] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Derivation of pluripotent stem cells (iPSCs) induced from somatic cell types and the subsequent genetic modifications of disease-specific or patient-specific iPSCs are crucial steps in their applications for disease modeling as well as future cell and gene therapies. Conventional procedures of these processes require co-culture with primary mouse embryonic fibroblasts (MEFs) to support self-renewal and clonal growth of human iPSCs as well as embryonic stem cells (ESCs). However, the variability of MEF quality affects the efficiencies of all these steps. Furthermore, animal sourced feeders may hinder the clinical applications of human stem cells. In order to overcome these hurdles, we established immortalized human feeder cell lines by stably expressing human telomerase reverse transcriptase, Wnt3a, and drug resistance genes in adult mesenchymal stem cells. Here, we show that these immortalized human feeders support efficient derivation of virus-free, integration-free human iPSCs and long-term expansion of human iPSCs and ESCs. Moreover, the drug-resistance feature of these feeders also supports nonviral gene transfer and expression at a high efficiency, mediated by piggyBac DNA transposition. Importantly, these human feeders exhibit superior ability over MEFs in supporting homologous recombination-mediated gene targeting in human iPSCs, allowing us to efficiently target a transgene into the AAVS1 safe harbor locus in recently derived integration-free iPSCs. Our results have great implications in disease modeling and translational applications of human iPSCs, as these engineered human cell lines provide a more efficient tool for genetic modifications and a safer alternative for supporting self-renewal of human iPSCs and ESCs.
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Affiliation(s)
- Chunlin Zou
- Cell Therapy Center, Xuanwu Hospital, Capital Medical University, Beijing, China
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29
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Huang Y, Pettitt SJ, Guo G, Liu G, Li MA, Yang F, Bradley A. Isolation of homozygous mutant mouse embryonic stem cells using a dual selection system. Nucleic Acids Res 2012; 40:e21. [PMID: 22127858 PMCID: PMC3273828 DOI: 10.1093/nar/gkr908] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 08/10/2011] [Accepted: 10/07/2011] [Indexed: 01/18/2023] Open
Abstract
Obtaining random homozygous mutants in mammalian cells for forward genetic studies has always been problematic due to the diploid genome. With one mutation per cell, only one allele of an autosomal gene can be disrupted, and the resulting heterozygous mutant is unlikely to display a phenotype. In cells with a genetic background deficient for the Bloom's syndrome helicase, such heterozygous mutants segregate homozygous daughter cells at a low frequency due to an elevated rate of crossover following mitotic recombination between homologous chromosomes. We constructed DNA vectors that are selectable based on their copy number and used these to isolate these rare homozygous mutant cells independent of their phenotype. We use the piggyBac transposon to limit the initial mutagenesis to one copy per cell, and select for cells that have increased the transposon copy number to two or more. This yields homozygous mutants with two allelic mutations, but also cells that have duplicated the mutant chromosome and become aneuploid during culture. On average, 26% of the copy number gain events occur by the mitotic recombination pathway. We obtained homozygous cells from 40% of the heterozygous mutants tested. This method can provide homozygous mammalian loss-of-function mutants for forward genetic applications.
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Affiliation(s)
- Yue Huang
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK and State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Department of Medical Genetics, Peking Union Medical College & Chinese Academy of Medical Sciences, Dong Dan San Tiao 5, Beijing 100005, China
| | - Stephen J. Pettitt
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK and State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Department of Medical Genetics, Peking Union Medical College & Chinese Academy of Medical Sciences, Dong Dan San Tiao 5, Beijing 100005, China
| | - Ge Guo
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK and State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Department of Medical Genetics, Peking Union Medical College & Chinese Academy of Medical Sciences, Dong Dan San Tiao 5, Beijing 100005, China
| | - Guang Liu
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK and State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Department of Medical Genetics, Peking Union Medical College & Chinese Academy of Medical Sciences, Dong Dan San Tiao 5, Beijing 100005, China
| | - Meng Amy Li
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK and State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Department of Medical Genetics, Peking Union Medical College & Chinese Academy of Medical Sciences, Dong Dan San Tiao 5, Beijing 100005, China
| | - Fengtang Yang
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK and State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Department of Medical Genetics, Peking Union Medical College & Chinese Academy of Medical Sciences, Dong Dan San Tiao 5, Beijing 100005, China
| | - Allan Bradley
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK and State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Department of Medical Genetics, Peking Union Medical College & Chinese Academy of Medical Sciences, Dong Dan San Tiao 5, Beijing 100005, China
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30
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Li MA, Turner DJ, Ning Z, Yusa K, Liang Q, Eckert S, Rad L, Fitzgerald TW, Craig NL, Bradley A. Mobilization of giant piggyBac transposons in the mouse genome. Nucleic Acids Res 2011; 39:e148. [PMID: 21948799 PMCID: PMC3239208 DOI: 10.1093/nar/gkr764] [Citation(s) in RCA: 122] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Revised: 08/15/2011] [Accepted: 09/01/2011] [Indexed: 11/14/2022] Open
Abstract
The development of technologies that allow the stable delivery of large genomic DNA fragments in mammalian systems is important for genetic studies as well as for applications in gene therapy. DNA transposons have emerged as flexible and efficient molecular vehicles to mediate stable cargo transfer. However, the ability to carry DNA fragments >10 kb is limited in most DNA transposons. Here, we show that the DNA transposon piggyBac can mobilize 100-kb DNA fragments in mouse embryonic stem (ES) cells, making it the only known transposon with such a large cargo capacity. The integrity of the cargo is maintained during transposition, the copy number can be controlled and the inserted giant transposons express the genomic cargo. Furthermore, these 100-kb transposons can also be excised from the genome without leaving a footprint. The development of piggyBac as a large cargo vector will facilitate a wider range of genetic and genomic applications.
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Affiliation(s)
- Meng Amy Li
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK, CB10 1SA and Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205-2185, USA
| | - Daniel J. Turner
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK, CB10 1SA and Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205-2185, USA
| | - Zemin Ning
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK, CB10 1SA and Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205-2185, USA
| | - Kosuke Yusa
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK, CB10 1SA and Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205-2185, USA
| | - Qi Liang
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK, CB10 1SA and Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205-2185, USA
| | - Sabine Eckert
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK, CB10 1SA and Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205-2185, USA
| | - Lena Rad
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK, CB10 1SA and Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205-2185, USA
| | - Tomas W. Fitzgerald
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK, CB10 1SA and Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205-2185, USA
| | - Nancy L. Craig
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK, CB10 1SA and Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205-2185, USA
| | - Allan Bradley
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK, CB10 1SA and Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205-2185, USA
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31
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A homozygous mutant embryonic stem cell bank applicable for phenotype-driven genetic screening. Nat Methods 2011; 8:1071-7. [PMID: 22020066 DOI: 10.1038/nmeth.1739] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Accepted: 08/19/2011] [Indexed: 12/25/2022]
Abstract
Genome-wide mutagenesis in mouse embryonic stem cells (ESCs) is a powerful tool, but the diploid nature of the mammalian genome hampers its application for recessive genetic screening. We have previously reported a method to induce homozygous mutant ESCs from heterozygous mutants by tetracycline-dependent transient disruption of the Bloom's syndrome gene. However, we could not purify homozygous mutants from a large population of heterozygous mutant cells, limiting the applications. Here we developed a strategy for rapid enrichment of homozygous mutant mouse ESCs and demonstrated its feasibility for cell-based phenotypic analysis. The method uses G418-plus-puromycin double selection to enrich for homozygotes and single-nucleotide polymorphism analysis for identification of homozygosity. We combined this simple approach with gene-trap mutagenesis to construct a homozygous mutant ESC bank with 138 mutant lines and demonstrate its use in phenotype-driven genetic screening.
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32
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Turan S, Bode J. Site‐specific recombinases: from tag‐and‐target‐ to tag‐and‐exchange‐based genomic modifications. FASEB J 2011; 25:4088-107. [DOI: 10.1096/fj.11-186940] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Soeren Turan
- Institute for Experimental Hematology, Hannover Medical School Hannover Germany
| | - Juergen Bode
- Institute for Experimental Hematology, Hannover Medical School Hannover Germany
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33
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Prosser HM, Koike-Yusa H, Cooper JD, Law FC, Bradley A. A resource of vectors and ES cells for targeted deletion of microRNAs in mice. Nat Biotechnol 2011; 29:840-5. [PMID: 21822254 PMCID: PMC3242032 DOI: 10.1038/nbt.1929] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Accepted: 07/05/2011] [Indexed: 02/01/2023]
Abstract
The 21-23 nucleotide, single-stranded RNAs classified as microRNAs (miRNA) perform fundamental roles in diverse cellular and developmental processes. In contrast to the situation for protein-coding genes, no public resource of miRNA mouse mutant alleles exists. Here we describe a collection of 428 miRNA targeting vectors covering 476 of the miRNA genes annotated in the miRBase registry. Using these vectors, we generated a library of highly germline-transmissible C57BL/6N mouse embryonic stem (ES) cell clones harboring targeted deletions for 392 miRNA genes. For most of these targeted clones, chimerism and germline transmission can be scored through a coat color marker. The targeted alleles have been designed to be adaptable research tools that can be efficiently altered by recombinase-mediated cassette exchange to create reporter, conditional and other allelic variants. This miRNA knockout (mirKO) resource can be searched electronically and is available from ES cell repositories for distribution to the scientific community.
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Affiliation(s)
- Haydn M Prosser
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK.
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34
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Wound healing characteristics of ICAM-1 null mice devoid of all isoforms of ICAM-1. J Surg Res 2011; 171:e1-7. [PMID: 21872884 DOI: 10.1016/j.jss.2011.06.053] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2011] [Revised: 05/24/2011] [Accepted: 06/22/2011] [Indexed: 11/24/2022]
Abstract
BACKGROUND Intercellular adhesion molecule-1 (ICAM-1) permits leukocyte-endothelial adhesion and transmigration during inflammation. Membrane-bound ICAM-1 knockout mice have been used to understand this molecule's role in wound-healing, but expressed spliced isoforms of ICAM-1 that may have impacted results. We aimed to characterize wound-healing in an ICAM-1 null model devoid of all ICAM-1 isoforms. METHODS Full-thickness 8-mm wounds were created on C57/BL6 wild-type (n = 24) and ICAM-1 null (n = 24) mice. Wound area was calculated using daily photographs. Histologic samples were harvested on postoperative Days 1, 3, 7, and 14. Wound margins were evaluated for mRNA expression of 13 inflammatory cytokines. A separate group of wild-type and ICAM-1 null mice (n = 24) received full-thickness incisions with tensiometry measured at Day 14. Separately, complete blood counts were measured in unwounded wild-type (n = 4) and ICAM-1 null mice (n = 4). RESULTS Wound-closure was significantly delayed in ICAM-1 null mice through Day 7 by gross and histologic measurement. mRNA expression of VEGF-A was increased in ICAM-1 null mice on Day 3, although no increase in VEGF-A was observed in the wound bed by immunohistochemistry. ICAM-1 null wounds demonstrated higher stiffness by tensiometry on Day 14 compared to the wild-type (1880 ± 926 kPa versus 478 ± 117 kPa; P < 0.01), and had higher counts of white blood cells (10,009 versus 5720 cells/μL, P < 0.05), neutrophils (2130 versus 630 cells/μL, P < 0.01), and lymphocytes (7130 versus 4,740 cells/μL, P < 0.05). CONCLUSIONS ICAM-1 null mice demonstrate delayed wound-healing and decreased wound elasticity compared to wild-type controls. This lag, however, was less than observed in earlier membrane-bound ICAM-1 knockouts, suggesting that other ICAM-1 isoforms may promote delayed wound-healing.
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35
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Chen SX, Osipovich AB, Ustione A, Potter LA, Hipkens S, Gangula R, Yuan W, Piston DW, Magnuson MA. Quantification of factors influencing fluorescent protein expression using RMCE to generate an allelic series in the ROSA26 locus in mice. Dis Model Mech 2011; 4:537-47. [PMID: 21324933 PMCID: PMC3124063 DOI: 10.1242/dmm.006569] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Accepted: 12/22/2010] [Indexed: 11/20/2022] Open
Abstract
Fluorescent proteins (FPs) have great utility in identifying specific cell populations and in studying cellular dynamics in the mouse. To quantify the factors that determine both the expression and relative brightness of FPs in mouse embryonic stem cells (mESCs) and in mice, we generated eight different FP-expressing ROSA26 alleles using recombinase-mediated cassette exchange (RMCE). These alleles enabled us to analyze the effects on FP expression of a translational enhancer and different 3'-intronic and/or polyadenylation sequences, as well as the relative brightness of five different FPs, without the confounding position and copy number effects that are typically associated with randomly inserted transgenes. We found that the expression of a given FP can vary threefold or more depending on the genetic features present in the allele. The optimal FP expression cassette contained both a translational enhancer sequence in the 5'-untranslated region (UTR) and an intron-containing rabbit β-globin sequence within the 3'-UTR. The relative expressed brightness of individual FPs varied up to tenfold. Of the five different monomeric FPs tested, Citrine (YFP) was the brightest, followed by Apple, eGFP, Cerulean (CFP) and Cherry. Generation of a line of Cherry-expressing mice showed that there was a 30-fold variation of Cherry expression among different tissues and that there was a punctate expression pattern within cells of all tissues examined. This study should help investigators make better-informed design choices when expressing FPs in mESCs and mice.
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Affiliation(s)
| | | | - Alessandro Ustione
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232-0494, USA
| | - Leah A. Potter
- Center for Stem Cell Biology and
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232-0494, USA
| | | | | | | | - David W. Piston
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232-0494, USA
| | - Mark A. Magnuson
- Center for Stem Cell Biology and
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232-0494, USA
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36
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Trex2 enables spontaneous sister chromatid exchanges without facilitating DNA double-strand break repair. Genetics 2011; 188:787-97. [PMID: 21546543 DOI: 10.1534/genetics.111.129833] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Trex2 is a 3' → 5' exonuclease that removes 3'-mismatched sequences in a biochemical assay; however, its biological function remains unclear. To address biology we previously generated trex2(null) mouse embryonic stem (ES) cells and expressed in these cells wild-type human TREX2 cDNA (Trex2(hTX2)) or cDNA with a single-amino-acid change in the catalytic domain (Trex2(H188A)) or in the DNA-binding domain (Trex2(R167A)). We found the trex2(null) and Trex2(H188A) cells exhibited spontaneous broken chromosomes and trex2(null) cells exhibited spontaneous chromosomal rearrangements. We also found ectopically expressed human TREX2 was active at the 3' ends of I-SceI-induced chromosomal double-strand breaks (DSBs). Therefore, we hypothesized Trex2 participates in DNA DSB repair by modifying 3' ends. This may be especially important for ends with damaged nucleotides. Here we present data that are unexpected and prompt a new model. We found Trex2-altered cells (null, H188A, and R167A) were not hypersensitive to camptothecin, a type-1 topoisomerase inhibitor that induces DSBs at replication forks. In addition, Trex2-altered cells were not hypersensitive to γ-radiation, an agent that causes DSBs throughout the cell cycle. This observation held true even in cells compromised for one of the two major DSB repair pathways: homology-directed repair (HDR) or nonhomologous end joining (NHEJ). Trex2 deletion also enhanced repair of an I-SceI-induced DSB by both HDR and NHEJ without affecting pathway choice. Interestingly, however, trex2(null) cells exhibited reduced spontaneous sister chromatid exchanges (SCEs) but this was not due to a defect in HDR-mediated crossing over. Therefore, reduced spontaneous SCE could be a manifestation of the same defect that caused spontaneous broken chromosomes and spontaneous chromosomal rearrangements. These unexpected data suggest Trex2 does not enable DSB repair and prompt a new model that posits Trex2 suppresses the formation of broken chromosomes.
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37
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Park D, Xiang AP, Mao FF, Zhang L, Di CG, Liu XM, Shao Y, Ma BF, Lee JH, Ha KS, Walton N, Lahn BT. Nestin is required for the proper self-renewal of neural stem cells. Stem Cells 2011; 28:2162-71. [PMID: 20963821 DOI: 10.1002/stem.541] [Citation(s) in RCA: 239] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The intermediate filament protein, nestin, is a widely employed marker of multipotent neural stem cells (NSCs). Recent in vitro studies have implicated nestin in a number of cellular processes, but there is no data yet on its in vivo function. Here, we report the construction and functional characterization of Nestin knockout mice. We found that these mice show embryonic lethality, with neuroepithelium of the developing neural tube exhibiting significantly fewer NSCs and much higher levels of apoptosis. Consistent with this in vivo observation, NSC cultures derived from knockout embryos show dramatically reduced self-renewal ability that is associated with elevated apoptosis but no overt defects in cell proliferation or differentiation. Unexpectedly, nestin deficiency has no detectable effect on the integrity of the cytoskeleton. Furthermore, the knockout of Vimentin, which abolishes nestin's ability to polymerize into intermediate filaments in NSCs, does not lead to any apoptotic phenotype. These data demonstrate that nestin is important for the proper survival and self-renewal of NSCs, and that this function is surprisingly uncoupled from nestin's structural involvement in the cytoskeleton.
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Affiliation(s)
- Donghyun Park
- Department of Human Genetics, University of Chicago, Howard Hughes Medical Institute, Chicago, Illinois, USA.
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38
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Kim TM, Ko JH, Choi YJ, Hu L, Hasty P. The phenotype of FancB-mutant mouse embryonic stem cells. Mutat Res 2011; 712:20-7. [PMID: 21458466 DOI: 10.1016/j.mrfmmm.2011.03.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2010] [Revised: 03/11/2011] [Accepted: 03/23/2011] [Indexed: 12/20/2022]
Abstract
Fanconi anemia (FA) is a rare autosomal recessive disease characterized by bone marrow failure, developmental defects and cancer. There are multiple FA genes that enable the repair of interstrand crosslinks (ICLs) in coordination with a variety of other DNA repair pathways in a way that is poorly understood. Here we present the phenotype of mouse embryonic stem (ES) cells mutated for FancB. We found FancB-mutant cells exhibited reduced cellular proliferation, hypersensitivity to the crosslinking agent mitomycin C (MMC), increased spontaneous and MMC-induced chromosomal abnormalities, reduced spontaneous sister chromatid exchanges (SCEs), reduced gene targeting, reduced MMC-induced Rad51 foci and absent MMC-induced FancD2 foci. Since FancB is on the X chromosome and since ES cells are typically XY, FancB is an excellent target for an epistatic analysis to elucidate FA's role in ICL repair.
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Affiliation(s)
- Tae Moon Kim
- Department of Molecular Medicine and Institute of Biotechnology, University of Texas Health Science Center at San Antonio, 15355 Lambda Drive, San Antonio, TX 78245, USA
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39
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Vassiliou GS, Cooper JL, Rad R, Li J, Rice S, Uren A, Rad L, Ellis P, Andrews R, Banerjee R, Grove C, Wang W, Liu P, Wright P, Arends M, Bradley A. Mutant nucleophosmin and cooperating pathways drive leukemia initiation and progression in mice. Nat Genet 2011; 43:470-5. [PMID: 21441929 PMCID: PMC3084174 DOI: 10.1038/ng.796] [Citation(s) in RCA: 162] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Accepted: 03/03/2011] [Indexed: 11/09/2022]
Abstract
Acute myeloid leukemia (AML) is a molecularly diverse malignancy with a poor prognosis whose largest subgroup is characterized by somatic mutations in NPM1, which encodes nucleophosmin. These mutations, termed NPM1c, result in cytoplasmic dislocation of nucleophosmin and are associated with distinctive transcriptional signatures, yet their role in leukemogenesis remains obscure. Here we report that activation of a humanized Npm1c knock-in allele in mouse hemopoietic stem cells causes Hox gene overexpression, enhanced self renewal and expanded myelopoiesis. One third of mice developed delayed-onset AML, suggesting a requirement for cooperating mutations. We identified such mutations using a Sleeping Beauty transposon, which caused rapid-onset AML in 80% of mice with Npm1c, associated with mutually exclusive integrations in Csf2, Flt3 or Rasgrp1 in 55 of 70 leukemias. We also identified recurrent integrations in known and newly discovered leukemia genes including Nf1, Bach2, Dleu2 and Nup98. Our results provide new pathogenetic insights and identify possible therapeutic targets in NPM1c+ AML.
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Affiliation(s)
- George S Vassiliou
- Mouse Genomics Team, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK.
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40
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Lim JH, Piedrahita JA, Jackson L, Ghashghaei T, Olby NJ. Development of a model of sacrocaudal spinal cord injury in cloned Yucatan minipigs for cellular transplantation research. Cell Reprogram 2011; 12:689-97. [PMID: 21108536 DOI: 10.1089/cell.2010.0039] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Research into transplantation strategies to treat spinal cord injury (SCI) is frequently performed in rodents, but translation of results to clinical patients can be poor and a large mammalian model of severe SCI is needed. The pig has been considered an optimal model species in which to perform preclinical testing, and the Yucatan minipig can be cloned successfully utilizing somatic cell nuclear transfer (SCNT). However, induction of paralysis in pigs poses significant welfare and nursing challenges. The present study was conducted to determine whether Yucatan SCNT clones could be used to develop an SCI animal model for cellular transplantation research. First, we demonstrated that transection of the sacrocaudal spinal cord in Yucatan SCNT clones produces profound, quantifiable neurological deficits restricted to the tail. We then established that neurospheres could be isolated from brain tissue of green fluorescence protein (GFP) transfected SCNT clones. Finally, we confirmed survival of transplanted GFP-expressing neural stem cells in the SCI lesion and their differentiation into glial and neuronal lineages for up to 4 weeks without immunosuppression. We conclude that this model of sacrocaudal SCI in Yucatan SCNT clones represents a powerful research tool to investigate the effect of cellular transplantation on axonal regeneration and functional recovery.
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Affiliation(s)
- Ji-Hey Lim
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina 27606, USA
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41
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Turan S, Galla M, Ernst E, Qiao J, Voelkel C, Schiedlmeier B, Zehe C, Bode J. Recombinase-Mediated Cassette Exchange (RMCE): Traditional Concepts and Current Challenges. J Mol Biol 2011; 407:193-221. [DOI: 10.1016/j.jmb.2011.01.004] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2010] [Revised: 01/04/2011] [Accepted: 01/04/2011] [Indexed: 12/18/2022]
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42
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Carlson DF, Garbe JR, Tan W, Martin MJ, Dobrinsky JR, Hackett PB, Clark KJ, Fahrenkrug SC. Strategies for selection marker-free swine transgenesis using the Sleeping Beauty transposon system. Transgenic Res 2011; 20:1125-37. [PMID: 21221779 DOI: 10.1007/s11248-010-9481-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Accepted: 12/22/2010] [Indexed: 12/11/2022]
Abstract
Swine transgenesis by pronuclear injection or cloning has traditionally relied on illegitimate recombination of DNA into the pig genome. This often results in animals containing concatemeric arrays of transgenes that complicate characterization and can impair long-term transgene stability and expression. This is inconsistent with regulatory guidance for transgenic livestock, which also discourages the use of selection markers, particularly antibiotic resistance genes. We demonstrate that the Sleeping Beauty (SB) transposon system effectively delivers monomeric, multi-copy transgenes to the pig embryo genome by pronuclear injection without markers, as well as to donor cells for founder generation by cloning. Here we show that our method of transposon-mediated transgenesis yielded 38 cloned founder pigs that altogether harbored 100 integrants for five distinct transposons encoding either human APOBEC3G or YFP-Cre. Two strategies were employed to facilitate elimination of antibiotic genes from transgenic pigs, one based on Cre-recombinase and the other by segregation of independently transposed transgenes upon breeding.
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Affiliation(s)
- Daniel F Carlson
- The Center for Genome Engineering, University of Minnesota, Minneapolis, MN 55455, USA
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43
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Hughes ED, Saunders TL. Gene Targeting in Embryonic Stem Cells. SPRINGER PROTOCOLS HANDBOOKS 2011. [DOI: 10.1007/978-3-662-45763-4_14] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
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44
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Probing human cardiovascular congenital disease using transgenic mouse models. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2011; 100:83-110. [PMID: 21377625 DOI: 10.1016/b978-0-12-384878-9.00003-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Congenital heart defects (CHDs) impact in utero embryonic viability, children, and surviving adults. Since the first transfer of genes into mice, transgenic mouse models have enabled researchers to experimentally study and genetically test the roles of genes in development, physiology, and disease progression. Transgenic mice have become a bona fide human CHD pathology model and their use has dramatically increased within the past two decades. Now that the entire mouse and human genomes are known, it is possible to knock out, mutate, misexpress, and/or replace every gene. Not only have transgenic mouse models changed our understanding of normal development, CHD processes, and the complex interactions of genes and pathways required during heart development, but they are also being used to identify new avenues for medical therapy.
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45
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Kozlov SV. Development of a cell-based assay to quantify the inflammatory potential of test substances and screen compound libraries for anti-cancer drug candidates in a high-throughput format. Methods Mol Biol 2009; 512:159-167. [PMID: 19347277 DOI: 10.1007/978-1-60327-530-9_9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Despite the current availability of an impressive in vitro assay battery developed to quantitatively analyze the broad panel of small compounds and macromolecules that possess the inflammatory potential, little methodology exists nowadays that affords a researcher or clinician to quantify the ultimate output on the level of cell signaling response caused by inflammatory pathway stimulation. As a matter of fact, majority of analytical tools measure bona fide inflammatory substances (e.g., cytokines or chemokines) by their direct binding to secondary reagents such as specific antibodies or other selectively affine substrates with the final readout generated via quantification of the resulting complexes. Although specific and highly reproducible, this approach provides no discrimination between biologically active versus inactive input analyte nor does it address the differential biological potential for the questioned substances related to their in vivo stability and biodistribution. In a search for alternative solutions, a novel strategy is emerging that employs cell-based methods of inflammatory substance measurements allowing to detect and quantify the downstream effects of analyte's activity translated in terms of inflammatory pathways stimulation. In addition, application of cell based assays simultaneously permits entry level evaluation of compound toxicity and endows with a powerful approach to perform high-throughput screenings of, e.g., small molecule libraries in a quest for novel compounds capable of influencing the inflammation process.
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Affiliation(s)
- Serguei V Kozlov
- Cancer and Developmental Biology Laboratory, National Cancer Institute at Frederick, Frederick, MD, USA
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46
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Abstract
Gene targeting in mice has been used extensively to elucidate gene function in vivo. However, for gene targeting to be successful, the targeting vector must be carefully designed. This chapter addresses the rationale behind designing targeting vectors, detailing the essential components, and highlighting specific considerations for different types of vectors, from gene deletions to point mutations and insertions. Examples of vector designs, cloning strategies, and approaches for successful screening of recombinants are described. The use of Cre/LoxP and Flp/frt systems for conditional targeting is described, together with strategies for generating conditional deletions. Methods for generating conditional point mutations are also described and their potential drawbacks discussed.
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Affiliation(s)
- J Simon
- Transgenic Service, College of Life Sciences, University of Dundee, Dundee, UK
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47
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Adams DJ, van der Weyden L. Contemporary approaches for modifying the mouse genome. Physiol Genomics 2008; 34:225-38. [PMID: 18559964 PMCID: PMC2519963 DOI: 10.1152/physiolgenomics.90242.2008] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2008] [Accepted: 06/11/2008] [Indexed: 12/05/2022] Open
Abstract
The mouse is a premiere experimental organism that has contributed significantly to our understanding of vertebrate biology. Manipulation of the mouse genome via embryonic stem (ES) cell technology makes it possible to engineer an almost limitless repertoire of mutations to model human disease and assess gene function. In this review we outline recent advances in mouse experimental genetics and provide a "how-to" guide for those people wishing to access this technology. We also discuss new technologies, such as transposon-mediated mutagenesis, and resources of targeting vectors and ES cells, which are likely to dramatically accelerate the pace with which we can assess gene function in vivo, and the progress of forward and reverse genetic screens in mice.
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Affiliation(s)
- David J Adams
- Experimental Cancer Genetics, The Wellcome Trust Sanger Institute, Hinxton, United Kingdom
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48
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Bockamp E, Sprengel R, Eshkind L, Lehmann T, Braun JM, Emmrich F, Hengstler JG. Conditional transgenic mouse models: from the basics to genome-wide sets of knockouts and current studies of tissue regeneration. Regen Med 2008; 3:217-35. [DOI: 10.2217/17460751.3.2.217] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Many mouse models are currently available, providing avenues to elucidate gene function and to recapitulate specific pathological conditions. To a large extent, successful translation of clinical evidence or analytical data into appropriate mouse models is possible through progress in transgenic or gene-targeting technology. Beginning with a review of standard mouse transgenics and conventional gene targeting, this article will move on to discussing the basics of conditional gene expression: the tetracycline (tet)-off and tet-on systems based on the transactivators tet-controlled transactivator (Tta) and reverse tet-on transactivator (rtTA) that allow downregulation or induction of gene expression; Cre or Flp recombinase-mediated modifications, including excision, inversion, insertion and interchromosomal translocation; combination of the tet and Cre systems, permitting inducible knockout, reporter gene activation or activation of point mutations; the avian retroviral system based on delivery of rtTA specifically into cells expressing the avian retroviral receptor, which enables cell type-specific, inducible gene expression; the tamoxifen system, one of the most frequently applied steroid receptor-based systems, allows rapid activation of a fusion protein between the gene of interest and a mutant domain of the estrogen receptor, whereby activation does not depend on transcription; and techniques for cell type-specific ablation. The diphtheria toxin receptor system offers the advantage that it can be combined with the ‘zoo’ of Cre recombinase driver mice. Having described the basics we move on to the cutting edge: generation of genome-wide sets of conditional knockout mice. To this end, large ongoing projects apply two strategies: gene trapping based on random integration of trapping vectors into introns leading to truncation of the transcript, and gene targeting, representing the directed approach using homologous recombination. It can be expected that in the near future genome-wide sets of such mice will be available. Finally, the possibilities of conditional expression systems for investigating gene function in tissue regeneration will be illustrated by examples for neurodegenerative disease, liver regeneration and wound healing of the skin.
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Affiliation(s)
- Ernesto Bockamp
- Johannes Gutenberg-Universität Mainz, Institute of Toxicology/Mouse Genetics, Obere Zahlbacher Str. 67,55131, Mainz, Germany
| | - Rolf Sprengel
- Max Planck Institute for Medical Research, D-69120 Heidelber, Germany
| | - Leonid Eshkind
- Johannes Gutenberg-Universität Mainz, Institute of Toxicology/Mouse Genetics, Obere Zahlbacher Str. 67,55131, Mainz, Germany
| | - Thomas Lehmann
- TRM-Leipzig, Philipp-Rosenthal-Strasse 55, University of Leipzig, 04103 Leipzig, Germany
| | - Jan M Braun
- University of Leipzig, Institute of Clinical Immunology and Transfusion Medicine (IKIT), Germany
| | - Frank Emmrich
- University of Leipzig, Institute of Clinical Immunology and Transfusion Medicine (IKIT), Germany
| | - Jan G Hengstler
- Dortmund University of Technology, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Institute of Legal Medicine and Rudolf-Boehm Institute of Pharmacology and Toxicology, University of Leipzig, Ardeystrasse 67, 44139 Dortmund, Germany
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49
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Sarić T, Frenzel LP, Hescheler J. Immunological barriers to embryonic stem cell-derived therapies. Cells Tissues Organs 2008; 188:78-90. [PMID: 18303241 DOI: 10.1159/000118784] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Replacement of diseased tissues with healthy cells derived from embryonic stem (ES) cells has a potential to become, in the future, a better alternative to current treatments of a number of conditions characterized by irreversible tissue injury, such as heart and liver failure, diabetes mellitus and neurodegeneration. However, several obstacles have to be overcome before this new therapeutic modality becomes part of a standard clinical practice. First of all, ethical and safety issues have to be resolved, the methodologies must be developed to enable obtaining sufficient amounts of differentiated cells, and the immune rejection of allogeneic cells must be prevented in order to ensure their long-term engraftment and function. Data on immunological properties of human and murine ES cells and their differentiated derivatives are controversial, ranging from those claiming unique immune-privileged properties for ES cells to those which refute these conclusions. This indicates that much more research is required to definitively understand the immunological features and engraftment capacity of ES cell derivatives. We review here the current state of the art in this new and exciting field of ES cell immunology and discuss the implications of these findings for the development of ES cell-based therapies.
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Affiliation(s)
- Tomo Sarić
- Center for Physiology, Medical Faculty of the University of Cologne, Cologne, Germany.
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50
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Mosaic complementation demonstrates a regulatory role for myosin VIIa in actin dynamics of stereocilia. Mol Cell Biol 2007; 28:1702-12. [PMID: 18160714 PMCID: PMC2258769 DOI: 10.1128/mcb.01282-07] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have developed a bacterial artificial chromosome transgenesis approach that allowed the expression of myosin VIIa from the mouse X chromosome. We demonstrated the complementation of the Myo7a null mutant phenotype producing a fine mosaic of two types of sensory hair cells within inner ear epithelia of hemizygous transgenic females due to X inactivation. Direct comparisons between neighboring auditory hair cells that were different only with respect to myosin VIIa expression revealed that mutant stereocilia are significantly longer than those of their complemented counterparts. Myosin VIIa-deficient hair cells showed an abnormally persistent tip localization of whirlin, a protein directly linked to elongation of stereocilia, in stereocilia. Furthermore, myosin VIIa localized at the tips of all abnormally short stereocilia of mice deficient for either myosin XVa or whirlin. Our results strongly suggest that myosin VIIa regulates the establishment of a setpoint for stereocilium heights, and this novel role may influence their normal staircase-like arrangement within a bundle.
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