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Motorina DM, Galimova YA, Battulina NV, Omelina ES. Systems for Targeted Silencing of Gene Expression and Their Application in Plants and Animals. Int J Mol Sci 2024; 25:5231. [PMID: 38791270 PMCID: PMC11121118 DOI: 10.3390/ijms25105231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 05/06/2024] [Accepted: 05/08/2024] [Indexed: 05/26/2024] Open
Abstract
At present, there are a variety of different approaches to the targeted regulation of gene expression. However, most approaches are devoted to the activation of gene transcription, and the methods for gene silencing are much fewer in number. In this review, we describe the main systems used for the targeted suppression of gene expression (including RNA interference (RNAi), chimeric transcription factors, chimeric zinc finger proteins, transcription activator-like effectors (TALEs)-based repressors, optogenetic tools, and CRISPR/Cas-based repressors) and their application in eukaryotes-plants and animals. We consider the advantages and disadvantages of each approach, compare their effectiveness, and discuss the peculiarities of their usage in plant and animal organisms. This review will be useful for researchers in the field of gene transcription suppression and will allow them to choose the optimal method for suppressing the expression of the gene of interest depending on the research object.
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Affiliation(s)
| | | | | | - Evgeniya S. Omelina
- Institute of Molecular and Cellular Biology, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia
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2
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Terzi F, Knabbe J, Cambridge SB. In Vivo Optical Interrogation of Neuronal Responses to Genetic, Cell Type-Specific Silencing. J Neurosci 2023; 43:8607-8620. [PMID: 37923378 PMCID: PMC10727181 DOI: 10.1523/jneurosci.2253-22.2023] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 05/05/2023] [Accepted: 06/26/2023] [Indexed: 11/07/2023] Open
Abstract
We established a low background, Cre-dependent version of the inducible Tet-On system for fast, cell type-specific transgene expression in vivo Coexpression of a constitutive, Cre-dependent fluorescent marker selectively allowed single-cell analyses before and after inducible, Tet-dependent transgene expression. Here, we used this method for precise, acute manipulation of neuronal activity in the living brain. The goal was to study neuronal network homeostasis at cellular resolution. Single induction of the potassium channel Kir2.1 produced cell type-specific silencing within hours that lasted for at least 3 d. Longitudinal in vivo imaging of spontaneous calcium transients and neuronal morphology demonstrated that prolonged silencing did not alter spine densities or synaptic input strength. Furthermore, selective induction of Kir2.1 in parvalbumin interneurons increased the activity of surrounding neurons in a distance-dependent manner. This high-resolution, inducible interference and interval imaging of individual cells (high I5, HighFive) method thus allows visualizing temporally precise, genetic perturbations of defined cells.SIGNIFICANCE STATEMENT Gene function is studied by KO or overexpression of a specific gene followed by analyses of phenotypic changes. However, being able to predict and analyze exactly those cells in which genetic manipulation will occur is not possible. We combined two prominent transgene overexpression methods to fluorescently highlight the targeted cells appropriately before cell type-specific transgene induction. By inducing a potassium channel that decreases neuronal firing, we investigated how neuronal networks in the living mouse brain possibly compensate swift changes in cellular activities. Unlike in vitro, known compensatory homeostatic mechanisms, such as changes in synapses, were not observed in vivo Overall, we demonstrated with our method rapid genetic manipulation and analysis of neuronal activities as well as precision transgene expression.
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Affiliation(s)
- Firat Terzi
- Heidelberg University, Heidelberg, 69120, Germany
| | | | - Sidney B Cambridge
- Heidelberg University, Heidelberg, 69120, Germany
- Dr. Senckenberg Anatomy, Institute for Anatomy II, Goethe-University Frankfurt am Main, Frankfurt, 60590, Germany
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3
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Terron HM, Maranan DS, Burgard LA, LaFerla FM, Lane S, Leissring MA. A Dual-Function "TRE-Lox" System for Genetic Deletion or Reversible, Titratable, and Near-Complete Downregulation of Cathepsin D. Int J Mol Sci 2023; 24:ijms24076745. [PMID: 37047718 PMCID: PMC10095275 DOI: 10.3390/ijms24076745] [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: 03/06/2023] [Revised: 04/01/2023] [Accepted: 04/03/2023] [Indexed: 04/14/2023] Open
Abstract
Commonly employed methods for reversibly disrupting gene expression, such as those based on RNAi or CRISPRi, are rarely capable of achieving >80-90% downregulation, making them unsuitable for targeting genes that require more complete disruption to elicit a phenotype. Genetic deletion, on the other hand, while enabling complete disruption of target genes, often produces undesirable irreversible consequences such as cytotoxicity or cell death. Here we describe the design, development, and detailed characterization of a dual-function "TRE-Lox" system for effecting either (a) doxycycline (Dox)-mediated downregulation or (b) genetic deletion of a target gene-the lysosomal aspartyl protease cathepsin D (CatD)-based on targeted insertion of a tetracycline-response element (TRE) and two LoxP sites into the 5' end of the endogenous CatD gene (CTSD). Using an optimized reverse-tetracycline transrepressor (rtTR) variant fused with the Krüppel-associated box (KRAB) domain, we show that CatD expression can be disrupted by as much as 98% in mouse embryonic fibroblasts (MEFs). This system is highly sensitive to Dox (IC50 = 1.46 ng/mL) and results in rapid (t1/2 = 0.57 d) and titratable downregulation of CatD. Notably, even near-total disruption of CatD expression was completely reversed by withdrawal of Dox. As expected, transient expression of Cre recombinase results in complete deletion of the CTSD gene. The dual functionality of this novel system will facilitate future studies of the involvement of CatD in various diseases, particularly those attributable to partial loss of CatD function. In addition, the TRE-Lox approach should be applicable to the regulation of other target genes requiring more complete disruption than can be achieved by traditional methods.
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Affiliation(s)
- Heather M Terron
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA 92697, USA
| | - Derek S Maranan
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA 92697, USA
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697, USA
| | - Luke A Burgard
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA 92697, USA
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697, USA
| | - Frank M LaFerla
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA 92697, USA
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697, USA
| | - Shelley Lane
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA 92697, USA
| | - Malcolm A Leissring
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA 92697, USA
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4
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TPX2 Amplification-Driven Aberrant Mitosis in Culture Adapted Human Embryonic Stem Cells with gain of 20q11.21. Stem Cell Rev Rep 2023:10.1007/s12015-023-10514-4. [PMID: 36862329 DOI: 10.1007/s12015-023-10514-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/28/2023] [Indexed: 03/03/2023]
Abstract
BACKGROUND Despite highly effective machinery for the maintenance of genome integrity in human embryonic stem cells (hESCs), the frequency of genetic aberrations during in-vitro culture has been a serious issue for future clinical applications. METHOD By passaging hESCs over a broad range of timepoints (up to 6 years), the isogenic hESC lines with different passage numbers with distinct cellular characteristics, were established. RESULT We found that mitotic aberrations, such as the delay of mitosis, multipolar centrosomes, and chromosome mis-segregation, were increased in parallel with polyploidy compared to early-passaged hESCs (EP-hESCs) with normal copy number. Through high-resolution genome-wide approaches and transcriptome analysis, we found that culture adapted-hESCs with a minimal amplicon in chromosome 20q11.21 highly expressed TPX2, a key protein for governing spindle assembly and cancer malignancy. Consistent with these findings, the inducible expression of TPX2 in EP-hESCs reproduced aberrant mitotic events, such as the delay of mitotic progression, spindle stabilization, misaligned chromosomes, and polyploidy. CONCLUSION These studies suggest that the increased transcription of TPX2 in culture adapted hESCs could contribute to an increase in aberrant mitosis due to altered spindle dynamics.
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5
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Bona A, Seifert M, Thünauer R, Zodel K, Frew IJ, Römer W, Walz G, Yakulov TA. MARVEL domain containing CMTM4 affects CXCR4 trafficking. Mol Biol Cell 2022; 33:ar116. [PMID: 36044337 PMCID: PMC9634968 DOI: 10.1091/mbc.e22-05-0152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The MARVEL proteins CMTM4 and CMTM6 control PD-L1, thereby influencing tumor immunity. We found that defective zebrafish cmtm4 slowed the development of the posterior lateral line (pLL) by altering the Cxcr4b gradient across the pLL primordium (pLLP). Analysis in mammalian cells uncovered that CMTM4 interacted with CXCR4, altering its glycosylation pattern, but did not affect internalization or degradation of CXCR4 in the absence of its ligand CXCL12. Synchronized release of CXCR4 from the endoplasmic reticulum revealed that CMTM4 slowed CXCR4 trafficking from the endoplasmic reticulum to the plasma membrane without affecting overall cell surface expression. Altered CXCR4 trafficking reduced ligand-induced CXCR4 degradation and affected AKT but not ERK1/2 activation. CMTM4 expression, in contrast to that of CXCR4, correlated with the survival of patients with renal cell cancer in the TCGA cohort. Furthermore, we observed that cmtm4 depletion promotes the separation of cells from the pLLP cell cluster in zebrafish embryos. Collectively, our findings indicate that CMTM4 exerts general roles in the biosynthetic pathway of cell surface molecules and seems to affect CXCR4-dependent cell migration.
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Affiliation(s)
- Alexandra Bona
- Renal Division and,Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, 79104 Freiburg, Germany,*Address correspondence to: Alexandra Bona (); Toma A. Yakulov ()
| | | | - Roland Thünauer
- Technology Platform Light Microscopy and Image Analysis (TP MIA), Leibniz Institute for Experimental Virology (HPI), 20251 Hamburg, Germany,Advanced Light and Fluorescence Microscopy (ALFM) Facility, Centre for Structural Systems Biology (CSSB), 22607 Hamburg, Germany
| | - Kyra Zodel
- Department of Medicine I, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Ian J. Frew
- Department of Medicine I, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany,German Cancer Consortium (DKTK), Partner Site Freiburg, and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany,Signalling Research Centres BIOSS and CIBSS
| | - Winfried Römer
- Signalling Research Centres BIOSS and CIBSS,Freiburg Institute for Advanced Studies (FRIAS), and,Faculty of Biology, Albert-Ludwigs-University Freiburg, 79104 Freiburg, Germany
| | - Gerd Walz
- Renal Division and,Signalling Research Centres BIOSS and CIBSS
| | - Toma A. Yakulov
- Renal Division and,*Address correspondence to: Alexandra Bona (); Toma A. Yakulov ()
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6
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Crone MA, MacDonald JT, Freemont PS, Siciliano V. gDesigner: computational design of synthetic gRNAs for Cas12a-based transcriptional repression in mammalian cells. NPJ Syst Biol Appl 2022; 8:34. [PMID: 36114193 PMCID: PMC9481559 DOI: 10.1038/s41540-022-00241-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 07/28/2022] [Indexed: 11/09/2022] Open
Abstract
Synthetic networks require complex intertwined genetic regulation often relying on transcriptional activation or repression of target genes. CRISPRi-based transcription factors facilitate the programmable modulation of endogenous or synthetic promoter activity and the process can be optimised by using software to select appropriate gRNAs and limit non-specific gene modulation. Here, we develop a computational software pipeline, gDesigner, that enables the automated selection of orthogonal gRNAs with minimized off-target effects and promoter crosstalk. We next engineered a Lachnospiraceae bacterium Cas12a (dLbCas12a)-based repression system that downregulates target gene expression by means of steric hindrance of the cognate promoter. Finally, we generated a library of orthogonal synthetic dCas12a-repressed promoters and experimentally demonstrated it in HEK293FT, U2OS and H1299 cells lines. Our system expands the toolkit of mammalian synthetic promoters with a new complementary and orthogonal CRISPRi-based system, ultimately enabling the design of synthetic promoter libraries for multiplex gene perturbation that facilitate the understanding of complex cellular phenotypes.
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Affiliation(s)
- Michael A Crone
- Section of Structural and Synthetic Biology, Department of Infectious Disease, Imperial College London, London, United Kingdom
- UK Dementia Research Institute Centre for Care Research and Technology, Imperial College London, London, United Kingdom
- London Biofoundry, Imperial College Translation and Innovation Hub, White City Campus, 84 Wood Lane, London, United Kingdom
| | - James T MacDonald
- Section of Structural and Synthetic Biology, Department of Infectious Disease, Imperial College London, London, United Kingdom.
| | - Paul S Freemont
- Section of Structural and Synthetic Biology, Department of Infectious Disease, Imperial College London, London, United Kingdom.
- UK Dementia Research Institute Centre for Care Research and Technology, Imperial College London, London, United Kingdom.
- London Biofoundry, Imperial College Translation and Innovation Hub, White City Campus, 84 Wood Lane, London, United Kingdom.
| | - Velia Siciliano
- Section of Structural and Synthetic Biology, Department of Infectious Disease, Imperial College London, London, United Kingdom.
- Istituto Italiano di Tecnologia IIT, Department of Synthetic and Systems Biology for Biomedicine, Genoa, Italy.
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7
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Fu W, Lei C, Wang C, Ma Z, Li T, Lin F, Mao R, Zhao J, Hu S. Synthetic libraries of immune cells displaying a diverse repertoire of chimaeric antigen receptors as a potent cancer immunotherapy. Nat Biomed Eng 2022; 6:842-854. [PMID: 35668107 DOI: 10.1038/s41551-022-00895-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 05/03/2022] [Indexed: 02/05/2023]
Abstract
Cancer immunotherapies rely on one or few specific tumour-associated antigens. However, the adaptive immune system relies on a large and diverse repertoire of antibodies for antigen recognition. Here we report the development and applicability of libraries of immune cells displaying diverse repertoires of chimaeric antigen receptors (CARs) that can recognize non-self antigens and display antigen-dependent clonal expansion, with the expanded population of tumour-specific effector cells leading to long-lasting antitumour responses in mouse models of epithelial tumours. The intravenous injection of synthetic libraries of murine CARs on TET2- T cells led to robust immunological memory and the recognition of mutated or evolved tumours, owing to the maintenance of CAR diversity. Off-the-shelf libraries of 106 murine or human CAR clones displayed on genetically modified human NK-92 cancer cells completely eliminated established tumours in mice with murine xenografts and patient-derived xenografts. Synthetically generated CAR libraries may aid the discovery of new CARs and the development of immunotherapies.
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Affiliation(s)
- Wenyan Fu
- Department of Assisted Reproduction, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Changhai Lei
- Department of Biophysics, College of Basic Medical Sciences, Naval Medical University (Second Military Medical University), Shanghai, China.,Team NMU-China of the International Genetically Engineered Machine Competition, Department of Biophysics, Naval Medical University (Second Military Medical University), Shanghai, China
| | - Chuqi Wang
- Department of Biophysics, College of Basic Medical Sciences, Naval Medical University (Second Military Medical University), Shanghai, China.,Team NMU-China of the International Genetically Engineered Machine Competition, Department of Biophysics, Naval Medical University (Second Military Medical University), Shanghai, China
| | - Zetong Ma
- Department of Biophysics, College of Basic Medical Sciences, Naval Medical University (Second Military Medical University), Shanghai, China.,Team NMU-China of the International Genetically Engineered Machine Competition, Department of Biophysics, Naval Medical University (Second Military Medical University), Shanghai, China
| | - Tian Li
- Department of Biophysics, College of Basic Medical Sciences, Naval Medical University (Second Military Medical University), Shanghai, China.,Team NMU-China of the International Genetically Engineered Machine Competition, Department of Biophysics, Naval Medical University (Second Military Medical University), Shanghai, China
| | - Fangxing Lin
- Department of Biophysics, College of Basic Medical Sciences, Naval Medical University (Second Military Medical University), Shanghai, China.,Team NMU-China of the International Genetically Engineered Machine Competition, Department of Biophysics, Naval Medical University (Second Military Medical University), Shanghai, China
| | - Ruixue Mao
- Team NMU-China of the International Genetically Engineered Machine Competition, Department of Biophysics, Naval Medical University (Second Military Medical University), Shanghai, China
| | - Jian Zhao
- KOCHKOR Biotech, Inc., Shanghai, China
| | - Shi Hu
- Department of Biophysics, College of Basic Medical Sciences, Naval Medical University (Second Military Medical University), Shanghai, China. .,Team NMU-China of the International Genetically Engineered Machine Competition, Department of Biophysics, Naval Medical University (Second Military Medical University), Shanghai, China.
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8
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Lensch S, Herschl MH, Ludwig CH, Sinha J, Hinks MM, Mukund A, Fujimori T, Bintu L. Dynamic spreading of chromatin-mediated gene silencing and reactivation between neighboring genes in single cells. eLife 2022; 11:e75115. [PMID: 35678392 PMCID: PMC9183234 DOI: 10.7554/elife.75115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 03/23/2022] [Indexed: 12/02/2022] Open
Abstract
In mammalian cells genes that are in close proximity can be transcriptionally coupled: silencing or activating one gene can affect its neighbors. Understanding these dynamics is important for natural processes, such as heterochromatin spreading during development and aging, and when designing synthetic gene regulation circuits. Here, we systematically dissect this process in single cells by recruiting and releasing repressive chromatin regulators at dual-gene synthetic reporters, and measuring how fast gene silencing and reactivation spread as a function of intergenic distance and configuration of insulator elements. We find that silencing by KRAB, associated with histone methylation, spreads between two genes within hours, with a time delay that increases with distance. This fast KRAB-mediated spreading is not blocked by the classical cHS4 insulators. Silencing by histone deacetylase HDAC4 of the upstream gene can also facilitate background silencing of the downstream gene by PRC2, but with a days-long delay that does not change with distance. This slower silencing can sometimes be stopped by insulators. Gene reactivation of neighboring genes is also coupled, with strong promoters and insulators determining the order of reactivation. Our data can be described by a model of multi-gene regulation that builds upon previous knowledge of heterochromatin spreading, where both gene silencing and gene reactivation can act at a distance, allowing for coordinated dynamics via chromatin regulator recruitment.
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Affiliation(s)
- Sarah Lensch
- Department of Bioengineering, Stanford UniversityStanfordUnited States
| | - Michael H Herschl
- University of California, Berkeley—University of California, San Francisco Graduate Program in BioengineeringBerkeleyUnited States
| | - Connor H Ludwig
- Department of Bioengineering, Stanford UniversityStanfordUnited States
| | - Joydeb Sinha
- Department of Chemical and Systems Biology, Stanford UniversityStanfordUnited States
| | - Michaela M Hinks
- Department of Bioengineering, Stanford UniversityStanfordUnited States
| | - Adi Mukund
- Biophysics Program, Stanford UniversityStanfordUnited States
| | - Taihei Fujimori
- Department of Bioengineering, Stanford UniversityStanfordUnited States
| | - Lacramioara Bintu
- Department of Bioengineering, Stanford UniversityStanfordUnited States
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9
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Bertram R, Neumann B, Schuster CF. Status quo of tet regulation in bacteria. Microb Biotechnol 2022; 15:1101-1119. [PMID: 34713957 PMCID: PMC8966031 DOI: 10.1111/1751-7915.13926] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 09/02/2021] [Accepted: 09/04/2021] [Indexed: 11/27/2022] Open
Abstract
The tetracycline repressor (TetR) belongs to the most popular, versatile and efficient transcriptional regulators used in bacterial genetics. In the tetracycline (Tc) resistance determinant tet(B) of transposon Tn10, tetR regulates the expression of a divergently oriented tetA gene that encodes a Tc antiporter. These components of Tn10 and of other natural or synthetic origins have been used for tetracycline-dependent gene regulation (tet regulation) in at least 40 bacterial genera. Tet regulation serves several purposes such as conditional complementation, depletion of essential genes, modulation of artificial genetic networks, protein overexpression or the control of gene expression within cell culture or animal infection models. Adaptations of the promoters employed have increased tet regulation efficiency and have made this system accessible to taxonomically distant bacteria. Variations of TetR, different effector molecules and mutated DNA binding sites have enabled new modes of gene expression control. This article provides a current overview of tet regulation in bacteria.
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Affiliation(s)
- Ralph Bertram
- Institute of Clinical Hygiene, Medical Microbiology and InfectiologyParacelsus Medical UniversityProf.‐Ernst‐Nathan‐Straße 1Nuremberg90419Germany
| | - Bernd Neumann
- Institute of Clinical Hygiene, Medical Microbiology and InfectiologyParacelsus Medical UniversityProf.‐Ernst‐Nathan‐Straße 1Nuremberg90419Germany
| | - Christopher F. Schuster
- Department of Infectious DiseasesDivision of Nosocomial Pathogens and Antibiotic ResistancesRobert Koch InstituteBurgstraße 37Wernigerode38855Germany
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10
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Lorenz P, Steinbeck F, Krause L, Thiesen HJ. The KRAB Domain of ZNF10 Guides the Identification of Specific Amino Acids That Transform the Ancestral KRAB-A-Related Domain Present in Human PRDM9 into a Canonical Modern KRAB-A Domain. Int J Mol Sci 2022; 23:1072. [PMID: 35162997 PMCID: PMC8835667 DOI: 10.3390/ijms23031072] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/11/2022] [Accepted: 01/13/2022] [Indexed: 12/14/2022] Open
Abstract
Krüppel-associated box (KRAB) zinc finger proteins are a large class of tetrapod transcription factors that usually exert transcriptional repression through recruitment of TRIM28/KAP1. The evolutionary root of modern KRAB domains (mKRAB) can be traced back to an ancestral motif (aKRAB) that occurs even in invertebrates. Here, we first stratified three subgroups of aKRAB sequences from the animal kingdom (PRDM9, SSX and coelacanth KZNF families) and defined ancestral subdomains for KRAB-A and KRAB-B. Using human ZNF10 mKRAB-AB as blueprints for function, we then identified the necessary amino acid changes that transform the inactive aKRAB-A of human PRDM9 into an mKRAB domain capable of mediating silencing and complexing TRIM28/KAP1 in human cells when employed as a hybrid with ZNF10-B. Full gain of function required replacement of residues KR by the conserved motif MLE (positionsA32-A34), which inserted an additional residue, and exchange of A9/S for F, A20/M for L, and A27/R for V. AlphaFold2 modelling documented an evolutionary conserved L-shaped body of two α-helices in all KRAB domains. It is transformed into a characteristic spatial arrangement typical for mKRAB-AB upon the amino acid replacements and in conjunction with a third helix supplied by mKRAB-B. Side-chains pointing outward from the core KRAB 3D structure may reveal a protein-protein interaction code enabling graded binding of TRIM28 to different KRAB domains. Our data provide basic insights into structure-function relationships and emulate transitions of KRAB during evolution.
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Affiliation(s)
- Peter Lorenz
- Rostock University Medical Center, Institute of Immunology, Schillingallee 70, 18057 Rostock, Germany; (F.S.); (L.K.); (H.-J.T.)
| | - Felix Steinbeck
- Rostock University Medical Center, Institute of Immunology, Schillingallee 70, 18057 Rostock, Germany; (F.S.); (L.K.); (H.-J.T.)
| | - Ludwig Krause
- Rostock University Medical Center, Institute of Immunology, Schillingallee 70, 18057 Rostock, Germany; (F.S.); (L.K.); (H.-J.T.)
| | - Hans-Jürgen Thiesen
- Rostock University Medical Center, Institute of Immunology, Schillingallee 70, 18057 Rostock, Germany; (F.S.); (L.K.); (H.-J.T.)
- Gesellschaft für Individualisierte Medizin (IndyMed) mbH, 17, 18055 Rostock, Germany
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11
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Conditional immortalization of human atrial myocytes for the generation of in vitro models of atrial fibrillation. Nat Biomed Eng 2022; 6:389-402. [PMID: 34992271 DOI: 10.1038/s41551-021-00827-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 10/29/2021] [Indexed: 12/12/2022]
Abstract
The lack of a scalable and robust source of well-differentiated human atrial myocytes constrains the development of in vitro models of atrial fibrillation (AF). Here we show that fully functional atrial myocytes can be generated and expanded one-quadrillion-fold via a conditional cell-immortalization method relying on lentiviral vectors and the doxycycline-controlled expression of a recombinant viral oncogene in human foetal atrial myocytes, and that the immortalized cells can be used to generate in vitro models of AF. The method generated 15 monoclonal cell lines with molecular, cellular and electrophysiological properties resembling those of primary atrial myocytes. Multicellular in vitro models of AF generated using the immortalized atrial myocytes displayed fibrillatory activity (with activation frequencies of 6-8 Hz, consistent with the clinical manifestation of AF), which could be terminated by the administration of clinically approved antiarrhythmic drugs. The conditional cell-immortalization method could be used to generate functional cell lines from other human parenchymal cells, for the development of in vitro models of human disease.
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12
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Suzuki T, Tanaka KF. Downregulation of Bdnf Expression in Adult Mice Causes Body Weight Gain. Neurochem Res 2022; 47:2645-2655. [PMID: 34982395 DOI: 10.1007/s11064-021-03523-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 12/20/2021] [Accepted: 12/28/2021] [Indexed: 10/19/2022]
Abstract
Gain or loss of appetite and resulting body weight changes are commonly observed in major depressive disorders (MDDs). Brain-derived neurotrophic factor (BDNF) is broadly expressed in the brain and is thought to play a role in the pathophysiology of MDDs and obesity. Congenital loss of function of BDNF causes weight gain in both humans and rodents; however, it is not clear whether acquired loss of function of BDNF also affects body weight. Thus, we exploited mutant mice in which the Bdnf expression level is regulated by the tetracycline-dependent transcriptional silencer (tTS)-tetracycline operator sequence (tetO) system. Time-controlled Bdnf expression using this system allowed us to establish congenital and acquired loss of function of Bdnf in mice. We demonstrated that changes in Bdnf expression influenced body weight during not only the developmental stage but also the adult stage of mice. Although it is still unclear whether acquired Bdnf loss of function in rodents mimics the pathology of MDD, our findings may bridge the mechanistic gap between MDDs and body weight gain in line with BDNF dysfunction.
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Affiliation(s)
- Toru Suzuki
- Division of Brain Sciences, Institute for Advanced Medical Research, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo, 160-8582, Japan
| | - Kenji F Tanaka
- Division of Brain Sciences, Institute for Advanced Medical Research, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo, 160-8582, Japan.
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13
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Combining Cell Fate Reprogramming and Protein Engineering to Study Transcription Factor Functions. Methods Mol Biol 2021. [PMID: 34324190 DOI: 10.1007/978-1-0716-1601-7_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Gene expression regulation by transcription factors plays a central role in determining and maintaining cell fate during normal development as well as induced cell fate reprogramming. Induction of cell identity-determining gene regulatory networks by reprogramming factors that act as transcriptional activators is key to induce desired cell fates. Conversely, repression of unwanted genetic programs by transcriptional repressors is equally important to ensure cell fate fidelity. Here we describe engineering techniques to create fusion proteins that allow exploration of the major transcriptional contribution (activation or repression) of specific neuronal reprogramming factors during direct cell fate conversion. This method can be extended to every reprogramming regime to enable the functional categorization of any transcription factor.
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14
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Azizoglu A, Brent R, Rudolf F. A precisely adjustable, variation-suppressed eukaryotic transcriptional controller to enable genetic discovery. eLife 2021; 10:69549. [PMID: 34342575 PMCID: PMC8421071 DOI: 10.7554/elife.69549] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 08/02/2021] [Indexed: 11/13/2022] Open
Abstract
Conditional expression of genes and observation of phenotype remain central to biological discovery. Current methods enable either on/off or imprecisely controlled graded gene expression. We developed a 'well-tempered' controller, WTC846, for precisely adjustable, graded, growth condition independent expression of genes in Saccharomyces cerevisiae. Controlled genes are expressed from a strong semisynthetic promoter repressed by the prokaryotic TetR, which also represses its own synthesis; with basal expression abolished by a second, 'zeroing' repressor. The autorepression loop lowers cell-to-cell variation while enabling precise adjustment of protein expression by a chemical inducer. WTC846 allelic strains in which the controller replaced the native promoters recapitulated known null phenotypes (CDC42, TPI1), exhibited novel overexpression phenotypes (IPL1), showed protein dosage-dependent growth rates and morphological phenotypes (CDC28, TOR2, PMA1 and the hitherto uncharacterized PBR1), and enabled cell cycle synchronization (CDC20). WTC846 defines an 'expression clamp' allowing protein dosage to be adjusted by the experimenter across the range of cellular protein abundances, with limited variation around the setpoint.
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Affiliation(s)
| | - Roger Brent
- Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, United States
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15
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Wagner HJ, Mohsenin H, Weber W. Synthetic Biology-Empowered Hydrogels for Medical Diagnostics. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2021; 178:197-226. [PMID: 33582837 DOI: 10.1007/10_2020_158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Synthetic biology is strongly inspired by concepts of engineering science and aims at the design and generation of artificial biological systems in different fields of research such as diagnostics, analytics, biomedicine, or chemistry. To this aim, synthetic biology uses an engineering approach relying on a toolbox of molecular sensors and switches that endows cellular hosts with non-natural computing functions and circuits. Importantly, this concept is not only limited to cellular approaches. Synthetic biological building blocks have also conferred sensing and switching capability to otherwise inactive materials. This principle has attracted high interest for the development of biohybrid materials capable of sensing and responding to specific molecular stimuli, such as disease biomarkers, antibiotics, or heavy metals. Moreover, the interconnection of individual sense-and-respond materials to complex materials systems has enabled the processing of, for example, multiple inputs or the amplification of signals using feedback topologies. Such systems holding high potential for applications in the analytical and diagnostic sectors will be described in this chapter.
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Affiliation(s)
- Hanna J Wagner
- Faculty of Biology, Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg im Breisgau, Germany.,Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - Hasti Mohsenin
- Faculty of Biology, Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg im Breisgau, Germany
| | - Wilfried Weber
- Faculty of Biology, Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg im Breisgau, Germany.
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16
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Kullmann MK, Pegka F, Ploner C, Hengst L. Stimulation of c-Jun/AP-1-Activity by the Cell Cycle Inhibitor p57 Kip2. Front Cell Dev Biol 2021; 9:664609. [PMID: 33928088 PMCID: PMC8076676 DOI: 10.3389/fcell.2021.664609] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 03/10/2021] [Indexed: 11/13/2022] Open
Abstract
p57 is a member of the Cip/Kip family of cell cycle inhibitors which restrict the eukaryotic cell cycle by binding to and inhibiting cyclin/CDK complexes. They are considered as tumor suppressors and inactivating genomic mutations of p57 are associated with human overgrowth disorders. Increasing evidence suggests that p57 controls additional cellular processes beyond cell cycle control such as apoptosis, cell migration or transcription. Here we report that p57 can stimulate AP-1 promotor activity. While transactivation by c-Jun is strongly activated by p57, it did not enhance c-Fos induced transcription. This indicates that c-Jun is the target of p57 in the canonical AP-1 heterodimeric transcription factor. We could detect endogenous p57/c-Jun containing complexes in cells by co-immunoprecipitation. The strong stimulation of c-Jun activity is not the consequence of activating phosphorylation in the transactivation domain (TAD) of c-Jun, but rather due to negative interference with c-Jun repressors and positive interference with c-Jun activators. In contrast to full-length p57, the amino- and carboxy-terminal domains of p57 are insufficient for a significant activation of c-Jun induced transcription. When expressed in presence of full length p57, the p57 C-terminus abrogated and the N-terminus enhanced c-Jun activation. This indicates that the C-terminus may bind and sequester a putative activator of c-Jun, whereas the N-terminus may sequester a c-Jun repressor. Interestingly, the p57 aminoterminus is sufficient for binding to the two c-Jun repressors HDAC1 and HDAC3. These data are consistent with a model of c-Jun activation where p57 is a part of large nuclear remodeling/transcription complexes. p57 might stimulate transcription by inhibiting transcription repressor proteins like HDACs via its N-terminus and/or attracting transcription activators through its C-terminus. These data suggest that in addition to its role as a CDK inhibitor and tumor suppressor, p57 may also exert tumor promoting functions by activation of the proto-oncoprotein c-Jun.
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Affiliation(s)
- Michael Keith Kullmann
- Institute of Medical Biochemistry, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Fragka Pegka
- Institute of Medical Biochemistry, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Christian Ploner
- Department of Plastic, Reconstructive and Aesthetic Surgery, Medical University of Innsbruck, Innsbruck, Austria
| | - Ludger Hengst
- Institute of Medical Biochemistry, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
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17
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Dalhoff A. Selective toxicity of antibacterial agents-still a valid concept or do we miss chances and ignore risks? Infection 2021; 49:29-56. [PMID: 33367978 PMCID: PMC7851017 DOI: 10.1007/s15010-020-01536-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 10/04/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND Selective toxicity antibacteribiotics is considered to be due to interactions with targets either being unique to bacteria or being characterized by a dichotomy between pro- and eukaryotic pathways with high affinities of agents to bacterial- rather than eukaryotic targets. However, the theory of selective toxicity oversimplifies the complex modes of action of antibiotics in pro- and eukaryotes. METHODS AND OBJECTIVE This review summarizes data describing multiple modes of action of antibiotics in eukaryotes. RESULTS Aminoglycosides, macrolides, oxazolidinones, chloramphenicol, clindamycin, tetracyclines, glycylcyclines, fluoroquinolones, rifampicin, bedaquillin, ß-lactams inhibited mitochondrial translation either due to binding to mitosomes, inhibition of mitochondrial RNA-polymerase-, topoisomerase 2ß-, ATP-synthesis, transporter activities. Oxazolidinones, tetracyclines, vancomycin, ß-lactams, bacitracin, isoniazid, nitroxoline inhibited matrix-metalloproteinases (MMP) due to chelation with zinc and calcium, whereas fluoroquinols fluoroquinolones and chloramphenicol chelated with these cations, too, but increased MMP activities. MMP-inhibition supported clinical efficacies of ß-lactams and daptomycin in skin-infections, and of macrolides, tetracyclines in respiratory-diseases. Chelation may have contributed to neuroprotection by ß-lactams and fluoroquinolones. Aminoglycosides, macrolides, chloramphenicol, oxazolidins oxazolidinones, tetracyclines caused read-through of premature stop codons. Several additional targets for antibiotics in human cells have been identified like interaction of fluoroquinolones with DNA damage repair in eukaryotes, or inhibition of mucin overproduction by oxazolidinones. CONCLUSION The effects of antibiotics on eukaryotes are due to identical mechanisms as their antibacterial activities because of structural and functional homologies of pro- and eukaryotic targets, so that the effects of antibiotics on mammals are integral parts of their overall mechanisms of action.
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Affiliation(s)
- Axel Dalhoff
- Christian-Albrechts-University of Kiel, Institue for Infection Medicine, Brunswiker Str. 4, D-24105, Kiel, Germany.
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18
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Zhou Y, Lei C, Zhu Z. A low-background Tet-On system based on post-transcriptional regulation using Csy4. PLoS One 2020; 15:e0244732. [PMID: 33378396 PMCID: PMC7773235 DOI: 10.1371/journal.pone.0244732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 12/15/2020] [Indexed: 12/04/2022] Open
Abstract
On account of its stringent regulation and high rate of induction, the tetracycline regulatory system is used extensively for inducing target gene expression in eukaryotes. However, under certain circumstances, its associated background expression can be problematic, as in the expression of highly toxic proteins. We found that when using the Tet-On 3G system to drive expression of the kid toxin gene in sf9 insect cells, a higher percentage of cells were killed than when using an empty vector in the absence of the induction agent doxycycline, thereby indicating the leaky expression of this inducible expression system. Moreover, we found that the tetracycline-controlled transcriptional silencer (tTS) does not effectively reduce the background expression of the Tet-On 3G system in sf9 cells. However, Csy4, a Cas9 homologous protein in the CRISPR family with sequence-specific endonuclease activity, was found to be effective in reducing the Tet-On 3G system-associated background expression, although there was a concomitant reduction in the maximum induced expression. Nevertheless, we found that modification of the system via incorporation of TRE-controlled anti-sense csy4 in combination with a WSSVie1 (Δ23) promotor-driven sense csy4 significantly reduced the leaky expression of the Tet-On 3G system, and that the level of induction was higher than that initially obtained. This optimized Tet-On 3G system can significantly reduce cell death attributed to the background expression of Kid under uninduced conditions. Therefore, we developed a novel low-background inducible expression system for use in insect cells and potentially in other organisms including mammals based on post-transcriptional regulation using Csy4.
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Affiliation(s)
- Yicheng Zhou
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Chaoliang Lei
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Zhihui Zhu
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, Hubei, China
- * E-mail:
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19
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Verbič A, Praznik A, Jerala R. A guide to the design of synthetic gene networks in mammalian cells. FEBS J 2020; 288:5265-5288. [PMID: 33289352 DOI: 10.1111/febs.15652] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 11/06/2020] [Accepted: 11/01/2020] [Indexed: 12/22/2022]
Abstract
Synthetic biology aims to harness natural and synthetic biological parts and engineering them in new combinations and systems, producing novel therapies, diagnostics, bioproduction systems, and providing information on the mechanism of function of biological systems. Engineering cell function requires the rewiring or de novo construction of cell information processing networks. Using natural and synthetic signal processing elements, researchers have demonstrated a wide array of signal sensing, processing and propagation modules, using transcription, translation, or post-translational modification to program new function. The toolbox for synthetic network design is ever-advancing and has still ample room to grow. Here, we review the diversity of synthetic gene networks, types of building modules, techniques of regulation, and their applications.
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Affiliation(s)
- Anže Verbič
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Arne Praznik
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Roman Jerala
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Ljubljana, Slovenia
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20
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Matantseva O, Berdieva M, Kalinina V, Pozdnyakov I, Pechkovskaya S, Skarlato S. Stressor-induced ecdysis and thecate cyst formation in the armoured dinoflagellates Prorocentrum cordatum. Sci Rep 2020; 10:18322. [PMID: 33110141 PMCID: PMC7591879 DOI: 10.1038/s41598-020-75194-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 10/12/2020] [Indexed: 11/09/2022] Open
Abstract
Ecdysis, the process of extensive cell covering rearrangement, represents a remarkable physiological trait of dinoflagellates. It is involved in the regulation of the population and bloom dynamics of these microorganisms, since it is required for the formation of their thin-walled cysts. This study presents laboratory data on ecdysis in Prorocentrum cordatum, a harmful dinoflagellate species of high environmental significance. We studied external stressors triggering this process and changes in the cell ultrastructure accompanying it. Our experiments showed that mass ecdysis and formation of cysts in P. cordatum could be induced by centrifugation, temperature decrease, changes in salinity, and treatment by 2,6-dichlorobenzonitrile, whereas temperature increase, changes in pH and treatment by tetracycline did not have this effect. Obtained cysts of P. cordatum did not contain the pellicular layer and were formed in the end of the first stage of this process, i.e. removal of the plasma membrane and the outer amphiesmal vesicle membrane, whereas its second stage, removal of theca, represented excystment. Based on our findings, we conclude that such cysts can be attributed to thecate cysts and suggest P. cordatum as a promising model organism for the investigation of cellular and molecular aspects of ecdysis in dinoflagellates.
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Affiliation(s)
- Olga Matantseva
- Laboratory of Cytology of Unicellular Organisms, Institute of Cytology of the Russian Academy of Sciences, Saint Petersburg, Russia.
| | - Mariia Berdieva
- Laboratory of Cytology of Unicellular Organisms, Institute of Cytology of the Russian Academy of Sciences, Saint Petersburg, Russia
| | - Vera Kalinina
- Laboratory of Cytology of Unicellular Organisms, Institute of Cytology of the Russian Academy of Sciences, Saint Petersburg, Russia
| | - Ilya Pozdnyakov
- Laboratory of Cytology of Unicellular Organisms, Institute of Cytology of the Russian Academy of Sciences, Saint Petersburg, Russia
| | - Sofia Pechkovskaya
- Laboratory of Cytology of Unicellular Organisms, Institute of Cytology of the Russian Academy of Sciences, Saint Petersburg, Russia
| | - Sergei Skarlato
- Laboratory of Cytology of Unicellular Organisms, Institute of Cytology of the Russian Academy of Sciences, Saint Petersburg, Russia
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21
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Suzuki S, Ohta KI, Nakajima Y, Shigeto H, Abe H, Kawai A, Miura R, Kazuki Y, Oshimura M, Miki T. Meganuclease-Based Artificial Transcription Factors. ACS Synth Biol 2020; 9:2679-2691. [PMID: 32907319 DOI: 10.1021/acssynbio.0c00083] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Embedding middle-scale artificial gene networks in live mammalian cells is one of the most important future goals for cell engineering. However, the applications of the highly orthogonal and conventional artificial transcription factors currently available are limited. In this study, we present a scalable pipeline to produce artificial transcription factors based on homing endonucleases, also known as meganucleases. The introduction of mutations at critical sites for nuclease activity renders these homing endonucleases a simple but highly specific DNA binding domain for their specific DNA target. The introduction of inactivated meganucleases linked to transcriptional activator domains strongly induced reporter gene expression, while their fusion to transcriptional repressor domains suppressed them. In addition, we show that inactivated meganuclease-based transcription factors could be embedded in the synthetic membrane receptor synNotch and used to construct synthetic circuits. These results suggest that inactivated meganucleases are useful DNA-binding domains for the construction of synthetic transcription factors in mammalian cells.
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Affiliation(s)
- Shingo Suzuki
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kagawa University, Miki-cho, Kagawa 761-0793, Japan
| | - Ken-ichi Ohta
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kagawa University, Miki-cho, Kagawa 761-0793, Japan
| | - Yoshihiro Nakajima
- Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Takamatsu, Kagawa 761-0395, Japan
| | - Hajime Shigeto
- Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Takamatsu, Kagawa 761-0395, Japan
| | - Hiroko Abe
- Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Takamatsu, Kagawa 761-0395, Japan
| | - Anna Kawai
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kagawa University, Miki-cho, Kagawa 761-0793, Japan
| | - Ryuichiro Miura
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kagawa University, Miki-cho, Kagawa 761-0793, Japan
| | - Yasuhiro Kazuki
- Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Chromosome Engineering Research Center, Tottori University, Yonago, 683-8503, Japan
| | - Mitsuo Oshimura
- Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Chromosome Engineering Research Center, Tottori University, Yonago, 683-8503, Japan
| | - Takanori Miki
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kagawa University, Miki-cho, Kagawa 761-0793, Japan
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Reprogramming and transdifferentiation - two key processes for regenerative medicine. Eur J Pharmacol 2020; 882:173202. [PMID: 32562801 DOI: 10.1016/j.ejphar.2020.173202] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 04/22/2020] [Accepted: 05/13/2020] [Indexed: 12/11/2022]
Abstract
Regenerative medicine based on transplants obtained from donors or foetal and new-born mesenchymal stem cells, encounter important obstacles such as limited availability of organs, ethical issues and immune rejection. The growing demand for therapeutic methods for patients being treated after serious accidents, severe organ dysfunction and an increasing number of cancer surgeries, exceeds the possibilities of the therapies that are currently available. Reprogramming and transdifferentiation provide powerful bioengineering tools. Both procedures are based on the somatic differentiated cells, which are easily and unlimitedly available, like for example: fibroblasts. During the reprogramming procedure mature cells are converted into pluripotent cells - which are capable to differentiate into almost any kind of desired cells. Transdifferentiation directly converts differentiated cells of one type into another differentiated cells type. Both procedures allow to obtained patient's dedicated cells for therapeutic purpose in regenerative medicine. In combination with biomaterials, it is possible to obtain even whole anatomical structures. Those patient's dedicated structures may serve for them upon serious accidents with massive tissue damage but also upon cancer surgeries as a replacement of damaged organ. Detailed information about reprogramming and transdifferentiation procedures as well as the current state of the art are presented in our review.
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23
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Tsujimura T, Takase O, Yoshikawa M, Sano E, Hayashi M, Hoshi K, Takato T, Toyoda A, Okano H, Hishikawa K. Controlling gene activation by enhancers through a drug-inducible topological insulator. eLife 2020; 9:47980. [PMID: 32369019 PMCID: PMC7200164 DOI: 10.7554/elife.47980] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 04/06/2020] [Indexed: 12/13/2022] Open
Abstract
While regulation of gene-enhancer interaction is intensively studied, its application remains limited. Here, we reconstituted arrays of CTCF-binding sites and devised a synthetic topological insulator with tetO for chromatin-engineering (STITCH). By coupling STITCH with tetR linked to the KRAB domain to induce heterochromatin and disable the insulation, we developed a drug-inducible system to control gene activation by enhancers. In human induced pluripotent stem cells, STITCH inserted between MYC and the enhancer down-regulated MYC. Progressive mutagenesis of STITCH led to a preferential escalation of the gene-enhancer interaction, corroborating the strong insulation ability of STITCH. STITCH also altered epigenetic states around MYC. Time-course analysis by drug induction uncovered deposition and removal of H3K27me3 repressive marks follows and reflects, but does not precede and determine, the expression change. Finally, STITCH inserted near NEUROG2 impaired the gene activation in differentiating neural progenitor cells. Thus, STITCH should be broadly useful for functional genetic studies.
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Affiliation(s)
- Taro Tsujimura
- Department of iPS Cell Research & Epigenetic Medicine, Keio University School of Medicine, Tokyo, Japan.,Department of Physiology, Keio University School of Medicine, Tokyo, Japan
| | - Osamu Takase
- Department of iPS Cell Research & Epigenetic Medicine, Keio University School of Medicine, Tokyo, Japan.,Department of Physiology, Keio University School of Medicine, Tokyo, Japan
| | - Masahiro Yoshikawa
- Department of iPS Cell Research & Epigenetic Medicine, Keio University School of Medicine, Tokyo, Japan.,Department of Physiology, Keio University School of Medicine, Tokyo, Japan
| | - Etsuko Sano
- Department of iPS Cell Research & Epigenetic Medicine, Keio University School of Medicine, Tokyo, Japan.,Department of Physiology, Keio University School of Medicine, Tokyo, Japan
| | - Matsuhiko Hayashi
- Apheresis and Dialysis Center, Keio University School of Medicine, Tokyo, Japan
| | - Kazuto Hoshi
- Division of Tissue Engineering, University of Tokyo Hospital, Tokyo, Japan.,Department of Oral and Maxillofacial Surgery, University of Tokyo Hospital, Tokyo, Japan
| | - Tsuyoshi Takato
- Division of Tissue Engineering, University of Tokyo Hospital, Tokyo, Japan.,Department of Oral and Maxillofacial Surgery, University of Tokyo Hospital, Tokyo, Japan
| | - Atsushi Toyoda
- Department of Genomics and Evolutionary Biology, National Institute of Genetics, Mishima, Japan
| | - Hideyuki Okano
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
| | - Keiichi Hishikawa
- Department of iPS Cell Research & Epigenetic Medicine, Keio University School of Medicine, Tokyo, Japan.,Department of Physiology, Keio University School of Medicine, Tokyo, Japan
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Al Chiblak M, Steinbeck F, Thiesen HJ, Lorenz P. DUF3669, a "domain of unknown function" within ZNF746 and ZNF777, oligomerizes and contributes to transcriptional repression. BMC Mol Cell Biol 2019; 20:60. [PMID: 31856708 PMCID: PMC6923878 DOI: 10.1186/s12860-019-0243-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 12/12/2019] [Indexed: 11/10/2022] Open
Abstract
Background ZNF746 and ZNF777 belong to a subset of the large Krüppel-associated box (KRAB) zinc finger (ZNF) transcription factor family. They contain, like four other members in human, an additional conserved domain, the “domain of unknown function 3669” (DUF3669). Previous work on members of this subfamily suggested involvement in transcriptional regulation and aberrant ZNF746 overexpression leads to neuronal cell death in Parkinson’s disease. Results Here we demonstrate that N-terminal protein segments of the ZNF746a major isoform and ZNF777 act in concert to exert moderate transcriptional repression activities. Full potency depended on the intact configuration consisting of DUF3669, a variant KRAB domain and adjacent sequences. While DUF3669 contributes an intrinsic weak inhibitory activity, the isolated KRAB-AB domains did not repress. Importantly, DUF3669 provides a novel protein-protein interaction interface and mediates direct physical interaction between the members of the subfamily in oligomers. The ZNF746 protein segment encoded by exons 5 and 6 boosted repressor potency, potentially due to the presence of an acceptor lysine for sumoylation at K189. Repressor activity of the potent canonical ZNF10 KRAB domain was not augmented by heterologous transfer of DUF3669, pointing to the importance of context for DUF3669’s impact on transcription. Neither ZNF746a nor ZNF777 protein segments stably associated with TRIM28 within cells. Isoform ZNF746b that contains, unlike the major isoform, a full-length KRAB-A subdomain, displayed substantially increased repressor potency. This increase is due to canonical mechanisms known for KRAB domains since it did not take place in HAP1 knockout models of TRIM28 and SETDB1. A glycine to glutamic acid replacement that complies with a bona fide conserved “MLE” sequence within KRAB-A led to a further strong gain in repressor potency to levels comparable to those of the canonical ZNF10 KRAB domain. Each gain of repressive activity was accompanied by an enhanced interaction with TRIM28 protein. Conclusion DUF3669 adds a protein-protein interaction surface to a subgroup of KRAB-ZNF proteins within an N-terminal configuration with variant KRAB and adjacent sequences likely regulated by sumoylation. DUF3669 contributes to transcriptional repression strength and its homo- and hetero-oligomerization characteristics probably extended the regulatory repertoire of KRAB-ZNF transcription factors during amniote evolution.
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Affiliation(s)
- Mohannad Al Chiblak
- Institute of Immunology, Rostock University Medical Center, Schillingallee 70, 18057, Rostock, Germany
| | - Felix Steinbeck
- Institute of Immunology, Rostock University Medical Center, Schillingallee 70, 18057, Rostock, Germany
| | - Hans-Jürgen Thiesen
- Institute of Immunology, Rostock University Medical Center, Schillingallee 70, 18057, Rostock, Germany
| | - Peter Lorenz
- Institute of Immunology, Rostock University Medical Center, Schillingallee 70, 18057, Rostock, Germany.
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Liu J, Volkers L, Jangsangthong W, Bart CI, Engels MC, Zhou G, Schalij MJ, Ypey DL, Pijnappels DA, de Vries AAF. Generation and primary characterization of iAM-1, a versatile new line of conditionally immortalized atrial myocytes with preserved cardiomyogenic differentiation capacity. Cardiovasc Res 2019; 114:1848-1859. [PMID: 29917042 PMCID: PMC6255688 DOI: 10.1093/cvr/cvy134] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 06/13/2018] [Indexed: 01/15/2023] Open
Abstract
Aims The generation of homogeneous cardiomyocyte populations from fresh tissue or stem cells is laborious and costly. A potential solution to this problem would be to establish lines of immortalized cardiomyocytes. However, as proliferation and (terminal) differentiation of cardiomyocytes are mutually exclusive processes, their permanent immortalization causes loss of electrical and mechanical functions. We therefore aimed at developing conditionally immortalized atrial myocyte (iAM) lines allowing toggling between proliferative and contractile phenotypes by a single-component change in culture medium composition. Methods and results Freshly isolated neonatal rat atrial cardiomyocytes (AMs) were transduced with a lentiviral vector conferring doxycycline (dox)-controlled expression of simian virus 40 large T antigen. Under proliferative conditions (i.e. in the presence of dox), the resulting cells lost most cardiomyocyte traits and doubled every 38 h. Under differentiation conditions (i.e. in the absence of dox), the cells stopped dividing and spontaneously reacquired a phenotype very similar to that of primary AMs (pAMs) in gene expression profile, sarcomeric organization, contractile behaviour, electrical properties, and response to ion channel-modulating compounds (as assessed by patch-clamp and optical voltage mapping). Moreover, differentiated iAMs had much narrower action potentials and propagated them at >10-fold higher speeds than the widely used murine atrial HL-1 cells. High-frequency electrical stimulation of confluent monolayers of differentiated iAMs resulted in re-entrant conduction resembling atrial fibrillation, which could be prevented by tertiapin treatment, just like in monolayers of pAMs. Conclusion Through controlled expansion and differentiation of AMs, large numbers of functional cardiomyocytes were generated with properties superior to the differentiated progeny of existing cardiomyocyte lines. iAMs provide an attractive new model system for studying cardiomyocyte proliferation, differentiation, metabolism, and (electro)physiology as well as to investigate cardiac diseases and drug responses, without using animals.
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Affiliation(s)
- Jia Liu
- Laboratory of Experimental Cardiology, Department of Cardiology, Leiden University Medical Center, Albinusdreef 2, RC Leiden, The Netherlands.,Department of Cell Biology and Genetics, Center for Anti-ageing and Regenerative Medicine, Shenzhen Key Laboratory for Anti-ageing and Regenerative Medicine, Shenzhen University Medical School, Shenzhen University, Nanhai Ave 3688, Shenzhen, China.,Netherlands Heart Institute, Holland Heart House, Moreelsepark 1, 3511 EP, Utrecht, The Netherlands
| | - Linda Volkers
- Laboratory of Experimental Cardiology, Department of Cardiology, Leiden University Medical Center, Albinusdreef 2, RC Leiden, The Netherlands
| | - Wanchana Jangsangthong
- Laboratory of Experimental Cardiology, Department of Cardiology, Leiden University Medical Center, Albinusdreef 2, RC Leiden, The Netherlands
| | - Cindy I Bart
- Laboratory of Experimental Cardiology, Department of Cardiology, Leiden University Medical Center, Albinusdreef 2, RC Leiden, The Netherlands
| | - Marc C Engels
- Laboratory of Experimental Cardiology, Department of Cardiology, Leiden University Medical Center, Albinusdreef 2, RC Leiden, The Netherlands
| | - Guangqian Zhou
- Department of Cell Biology and Genetics, Center for Anti-ageing and Regenerative Medicine, Shenzhen Key Laboratory for Anti-ageing and Regenerative Medicine, Shenzhen University Medical School, Shenzhen University, Nanhai Ave 3688, Shenzhen, China
| | - Martin J Schalij
- Laboratory of Experimental Cardiology, Department of Cardiology, Leiden University Medical Center, Albinusdreef 2, RC Leiden, The Netherlands
| | - Dirk L Ypey
- Laboratory of Experimental Cardiology, Department of Cardiology, Leiden University Medical Center, Albinusdreef 2, RC Leiden, The Netherlands
| | - Daniël A Pijnappels
- Laboratory of Experimental Cardiology, Department of Cardiology, Leiden University Medical Center, Albinusdreef 2, RC Leiden, The Netherlands
| | - Antoine A F de Vries
- Laboratory of Experimental Cardiology, Department of Cardiology, Leiden University Medical Center, Albinusdreef 2, RC Leiden, The Netherlands.,Netherlands Heart Institute, Holland Heart House, Moreelsepark 1, 3511 EP, Utrecht, The Netherlands
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Kallunki T, Barisic M, Jäättelä M, Liu B. How to Choose the Right Inducible Gene Expression System for Mammalian Studies? Cells 2019; 8:cells8080796. [PMID: 31366153 PMCID: PMC6721553 DOI: 10.3390/cells8080796] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 07/18/2019] [Accepted: 07/26/2019] [Indexed: 12/20/2022] Open
Abstract
Inducible gene expression systems are favored over stable expression systems in a wide variety of basic and applied research areas, including functional genomics, gene therapy, tissue engineering, biopharmaceutical protein production and drug discovery. This is because they are mostly reversible and thus more flexible to use. Furthermore, compared to constitutive expression, they generally exhibit a higher efficiency and have fewer side effects, such as cell death and delayed growth or development. Empowered by decades of development of inducible gene expression systems, researchers can now efficiently activate or suppress any gene, temporarily and quantitively at will, depending on experimental requirements and designs. Here, we review a number of most commonly used mammalian inducible expression systems and provide basic standards and criteria for the selection of the most suitable one.
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Affiliation(s)
- Tuula Kallunki
- Cell Death and Metabolism, Center for Autophagy, Recycling and Disease, Danish Cancer Society Research Center, 2100 Copenhagen, Denmark
- Department of Drug Design and Pharmacology, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Marin Barisic
- Cell Division and Cytoskeleton, Danish Cancer Society Research Center, 2100 Copenhagen, Denmark
- Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Marja Jäättelä
- Cell Death and Metabolism, Center for Autophagy, Recycling and Disease, Danish Cancer Society Research Center, 2100 Copenhagen, Denmark
- Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Bin Liu
- Cell Death and Metabolism, Center for Autophagy, Recycling and Disease, Danish Cancer Society Research Center, 2100 Copenhagen, Denmark.
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27
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Thiesen HJ. From repression domains to designer zinc finger proteins: a novel strategy of intracellular immunization against HIV. Gene Expr 2018; 5:229-43. [PMID: 8723389 PMCID: PMC6138030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Tissue-specific gene regulation of eukaryotic organisms is to a large extent mediated by transcription factors that interact with genomic DNA sequences in a sequence-specific manner. The purpose of this synopsis is to put forward the potential of designer zinc finger proteins in treating infections of human immunodeficiency virus (HIV). Artificial transcription factors containing designer zinc finger structures fused to activator or repressor domains have been designated Transcription Response Modifiers (TRMs). The principle of engineering TRMs has been derived from the analysis of human Krüppel-type zinc finger genes and their products. Our research efforts encompass two fascinating features that are displayed by the human Krüppel-type zinc finger protein KOX1: 1) the Krüppel-type zinc finger domains display rules of sequence-specific DNA recognition, and 2) the evolutionarily conserved Krüppel-associated box (KRAB) presents one of the strongest transcriptional repressors identified so far in mammalian organisms. The KRAB repressor activity is postulated to be mediated through co-repressor molecules, such as Silencing Mediating Protein-1 (SMP-1). Thus, the structural organization and functional analysis of zinc finger proteins revealed principles of zinc finger transcription factors that are applicable for reducing the viral load in individuals infected with HIV. In this article, a novel concept of generating therapeutic proteins is outlined that might be conceptually promising in modulating gene expressions of any kind.
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Costello A, Lao NT, Gallagher C, Capella Roca B, Julius LAN, Suda S, Ducrée J, King D, Wagner R, Barron N, Clynes M. Leaky Expression of the TET-On System Hinders Control of Endogenous miRNA Abundance. Biotechnol J 2018; 14:e1800219. [PMID: 29989353 DOI: 10.1002/biot.201800219] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 06/08/2018] [Indexed: 12/12/2022]
Abstract
With the ability to affect multiple genes and fundamental pathways simultaneously, miRNA engineering of Chinese Hamster Ovary (CHO) cells has significant advantages over single gene expression or repression. Tight control of these molecular triggers is desirable as it could in theory allow on/off or even tunable regulation of desirable cellular phenotypes. The present study investigated the potential of employing a tetracycline inducible (TET-On) system for conditional knockdown of specific miRNAs but encountered several challenges. The authors show a significant reduction in cell proliferation and culture viability when maintained in media supplemented with the TET-On induction agent Doxycycline at concentrations commonly reported. Calculation of a mature miRNA and miRNA sponge mRNA copy number demonstrates that leaky basal transgene expression in the un-induced state, is sufficient for significant miRNA knockdown. This work highlights challenges of the TET-On inducible expression system for controlled manipulation of endogenous miRNAs with two examples; miR-378 and miR-455. The authors suggest a solution involving isolation of highly inducible clones and use a single cell analysis platform to demonstrate the heterogeneity of basal expression and inducibility. Finally, the authors describe numerous strategies to minimize leaky transgene expression and alterations to current miRNA sponge design.
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Affiliation(s)
- Alan Costello
- National Institute for Cellular Biotechnology, Dublin City University, D09 NR58, Dublin, Ireland
| | - Nga T Lao
- National Institute for Cellular Biotechnology, Dublin City University, D09 NR58, Dublin, Ireland
| | - Clair Gallagher
- National Institute for Cellular Biotechnology, Dublin City University, D09 NR58, Dublin, Ireland
| | - Berta Capella Roca
- National Institute for Cellular Biotechnology, Dublin City University, D09 NR58, Dublin, Ireland
| | | | - Srinivas Suda
- National Institute for Bioprocessing Research and Training, University College Dublin, Dublin, Ireland
| | - Jens Ducrée
- Fraunhofer Project Centre, Dublin City University, Dublin, Ireland
| | - Damien King
- Fraunhofer Project Centre, Dublin City University, Dublin, Ireland
| | | | - Niall Barron
- National Institute for Bioprocessing Research and Training, University College Dublin, Dublin, Ireland
| | - Martin Clynes
- National Institute for Cellular Biotechnology, Dublin City University, D09 NR58, Dublin, Ireland
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Weisenberger MS, Deans TL. Bottom-up approaches in synthetic biology and biomaterials for tissue engineering applications. J Ind Microbiol Biotechnol 2018; 45:599-614. [PMID: 29552703 PMCID: PMC6041164 DOI: 10.1007/s10295-018-2027-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Accepted: 03/11/2018] [Indexed: 12/30/2022]
Abstract
Synthetic biologists use engineering principles to design and construct genetic circuits for programming cells with novel functions. A bottom-up approach is commonly used to design and construct genetic circuits by piecing together functional modules that are capable of reprogramming cells with novel behavior. While genetic circuits control cell operations through the tight regulation of gene expression, a diverse array of environmental factors within the extracellular space also has a significant impact on cell behavior. This extracellular space offers an addition route for synthetic biologists to apply their engineering principles to program cell-responsive modules within the extracellular space using biomaterials. In this review, we discuss how taking a bottom-up approach to build genetic circuits using DNA modules can be applied to biomaterials for controlling cell behavior from the extracellular milieu. We suggest that, by collectively controlling intrinsic and extrinsic signals in synthetic biology and biomaterials, tissue engineering outcomes can be improved.
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Affiliation(s)
| | - Tara L Deans
- Department of Bioengineering, University of Utah, Salt Lake City, UT, 84112, USA.
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30
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In-situ NIR-laser mediated bioactive substance delivery to single cell for EGFP expression based on biocompatible microchamber-arrays. J Control Release 2018; 276:84-92. [PMID: 29501723 DOI: 10.1016/j.jconrel.2018.02.044] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Revised: 02/26/2018] [Accepted: 02/28/2018] [Indexed: 11/21/2022]
Abstract
Controlled drug delivery and gene expression is required for a large variety of applications including cancer therapy, wound healing, cell migration, cell modification, cell-analysis, reproductive and regenerative medicine. Controlled delivery of precise amounts of drugs to a single cell is especially interesting for cell and tissue engineering as well as therapeutics and has until now required the application of micro-pipettes, precisely placed dispersed drug delivery vehicles, or injections close to or into the cell. Here we present surface bound micro-chamber arrays able to store small hydrophilic molecules for prolonged times in subaqueous conditions supporting spatiotemporal near infrared laser mediated release. The micro-chambers (MCs) are composed of biocompatible and biodegradable polylactic acid (PLA). Biocompatible gold nanoparticles are employed as light harvesting agents to facilitate photothermal MC opening. The degree of photothermal heating is determined by numerical simulations utilizing optical properties of the MC, and confirmed by Brownian motion measurements of laser-irradiated micro-particles exhibiting similar optical properties like the MCs. The amount of bioactive small molecular cargo (doxycycline) from local release is determined by fluorescence spectroscopy and gene expression in isolated C2C12 cells via enhanced green fluorescent protein (EGFP) biosynthesis.
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31
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Abstract
RNA interference (RNAi) has become an essential technology for functional gene analysis. Its success depends on the effective expression of target gene-specific RNAi-inducing small double-stranded interfering RNA molecules (siRNAs). Here, were describe the use of a recently developed lentiviral RNAi system that allows the rapid generation of stable cell lines with inducible RNAi based on conditional expression of double-stranded short hairpin RNA (shRNA). These lentiviral vectors can be generated rapidly using the GATEWAY recombination cloning technology. Conditional cell lines can be established by using either a two-vector system in which the regulator is encoded by a separate vector or by a one-vector system. The available different lentiviral vectors for conditional shRNA expression cassette delivery co-express additional genes that allow (1) the use of fluorescent proteins for color-coded combinatorial RNAi or monitoring RNAi induction (pGLTR-FP), (2) selection of transduced cells (pGLTR-S), and (3) the generation of conditional cell lines using a one-vector system (pGLTR-X).
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32
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Tycko J, Van MV, Elowitz MB, Bintu L. Advancing towards a global mammalian gene regulation model through single-cell analysis and synthetic biology. CURRENT OPINION IN BIOMEDICAL ENGINEERING 2017. [DOI: 10.1016/j.cobme.2017.10.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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33
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The Tetracycline Responsive System. Methods Mol Biol 2017. [PMID: 28801906 DOI: 10.1007/978-1-4939-7223-4_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Constitutive gene expression is not always the appropriate expression system because the unphysiological levels of expressed protein could be detrimental in studies examining biological roles of proteins, or continued expression may be unnecessary after therapeutic effects have been achieved in gene therapy . We have utilized pharmacologically regulated gene expression systems to achieve fine control of gene expression levels which facilitate research in basic biology and translates to use in experimental gene therapy studies. In this chapter, we outline the application of a tightly controlled tetracycline responsive gene expression system.
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Tada K, Roy-Chowdhury N, Prasad V, Kim BH, Manchikalapudi P, Fox IJ, van Duijvendijk P, Bosma PJ, Roy-Chowdhury J. Long-Term Amerlioration of Bilirubin Glucuronidation Defect in Gunn Rats by Transplanting Genetically Modified Immortalized Autologous Hepatocytes. Cell Transplant 2017; 7:607-16. [PMID: 9853589 DOI: 10.1177/096368979800700611] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Ex vivo gene therapy, in which hepatocytes are harvested from mutants, retrovirally transduced with a normal gene and transplanted back into the donor, has been used for correction of inherited metabolic defects of liver. Major drawbacks of this method include limited availability of autologous hepatocytes, inefficient retroviral transduction of primary hepatocytes, and the limited number of hepatocytes that can be transplanted safely. To obviate these problems, we transduced primary hepatocytes derived from inbred bilirubin–UDP–glucuronosyl–transferase (BUGT)-deficient Gunn rats by infection with a recombinant retrovirus expressing temperature-sensitive mutant SV40 large T antigen (tsT). The immortalized cells were then transduced with a second recombinant retrovirus expressing human B-UGT, and a clone expressing high levels of the enzyme was expanded by culturing at permissive temperature (33°C). At 37°C, tsT antigen was degraded and the cells expressed UGT activity toward bilirubin at a level approximately twice that present in normal rat liver homogenates. For seeding the cells into the liver bed, 1 × 107 cells were injected into the spleens of syngeneic Gunn rats five times at 10-day intervals. Excretion of bilirubin glucuronides in bile was demonstrated by HPLC analysis and serum bilirubin levels were reduced by 27 to 52% in 40 days after the first transplantation and remained so throughout the duration of the study (120 days). None of the transplanted Gunn rats or SCID mice transplanted with the immortalized cells developed tumors. © 1998 Elsevier Science Inc.
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Affiliation(s)
- K Tada
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10462, USA
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35
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Schmitter S, Fieseler L, Klumpp J, Bertram R, Loessner MJ. TetR-dependent gene regulation in intracellularListeria monocytogenesdemonstrates the spatiotemporal surface distribution of ActA. Mol Microbiol 2017; 105:413-425. [DOI: 10.1111/mmi.13706] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/11/2017] [Indexed: 10/19/2022]
Affiliation(s)
- Sibylle Schmitter
- Institute of Food, Nutrition and Health; ETH Zurich; Schmelzbergstrasse 7 Zurich CH-8092 Switzerland
| | - Lars Fieseler
- Institute of Food, Nutrition and Health; ETH Zurich; Schmelzbergstrasse 7 Zurich CH-8092 Switzerland
| | - Jochen Klumpp
- Institute of Food, Nutrition and Health; ETH Zurich; Schmelzbergstrasse 7 Zurich CH-8092 Switzerland
| | - Ralph Bertram
- Lehrbereich Mikrobielle Genetik; Eberhard-Karls-Universität Tübingen; Auf der Morgenstelle 28 Tübingen D-72076 Germany
| | - Martin J. Loessner
- Institute of Food, Nutrition and Health; ETH Zurich; Schmelzbergstrasse 7 Zurich CH-8092 Switzerland
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36
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Li S, Ma L, Ou M, Feng J, Liao Y, Wang G, Tang L. A novel inducible lentiviral system for multi-gene expression with human HSP70 promoter and tetracycline-induced promoter. Appl Microbiol Biotechnol 2017; 101:3689-3702. [PMID: 28160047 DOI: 10.1007/s00253-017-8132-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 01/03/2017] [Accepted: 01/10/2017] [Indexed: 01/04/2023]
Abstract
Despite lentiviral system's predominance, its ultimate potential for gene therapy has not been fully exploited. Currently, most lentivirus vectors are non-inducible expression system or single-gene-induced system, which limits the extensive application in gene therapy. In this study, we designed a novel lentiviral vector containing HSP70 promoter and TRE promoter. Compared to traditional lentiviral vectors and inducible vectors, our controllable system has many advantages. Firstly, it contains multiple gene or shRNA targets. Secondly, genes expression is on/off in response to heat shock and DOX induction in time of need respectively with high effectivity and sensitivity. Thirdly, TRE promoter and HSP70 promoter can work with no interference from each other in the same inducible lentiviral vector. In addition, our study also shows that our novel vector has a higher downstream gene expression efficiency than co-transfection method and can co-position multi-genes in single cell effectively. Finally, we propose four derived models based on our vector at the end, which may be useful in biological research and clinical research in the future. Therefore, we believe that this novel lentiviral system could be promising in gene therapy for tumor.
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Affiliation(s)
- Shun Li
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, 400044, China
- State and Local Joint Engineering Laboratory for Vascular Implants, Chongqing, 400044, China
| | - Lunkun Ma
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, 400044, China
- State and Local Joint Engineering Laboratory for Vascular Implants, Chongqing, 400044, China
| | - Mengting Ou
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, 400044, China
- State and Local Joint Engineering Laboratory for Vascular Implants, Chongqing, 400044, China
| | - Jianguo Feng
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, 400044, China
- State and Local Joint Engineering Laboratory for Vascular Implants, Chongqing, 400044, China
- Department of Anesthesiology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan Province, 646000, China
| | - Yi Liao
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, 400044, China
- State and Local Joint Engineering Laboratory for Vascular Implants, Chongqing, 400044, China
- Department of Cardiothoracic Surgery, Southwest Hospital, Third Military Medical University, Chongqing, 400044, China
| | - Guixue Wang
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, 400044, China
- State and Local Joint Engineering Laboratory for Vascular Implants, Chongqing, 400044, China
| | - Liling Tang
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, 400044, China.
- State and Local Joint Engineering Laboratory for Vascular Implants, Chongqing, 400044, China.
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Hancock R, Masson N, Dunne K, Flashman E, Kawamura A. The Activity of JmjC Histone Lysine Demethylase KDM4A is Highly Sensitive to Oxygen Concentrations. ACS Chem Biol 2017; 12:1011-1019. [PMID: 28051298 PMCID: PMC5404277 DOI: 10.1021/acschembio.6b00958] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 01/04/2017] [Indexed: 01/04/2023]
Abstract
The JmjC histone lysine demethylases (KDMs) are epigenetic regulators involved in the removal of methyl groups from post-translationally modified lysyl residues within histone tails, modulating gene transcription. These enzymes require molecular oxygen for catalytic activity and, as 2-oxoglutarate (2OG)-dependent oxygenases, are related to the cellular oxygen sensing HIF hydroxylases PHD2 and FIH. Recent studies have indicated that the activity of some KDMs, including the pseudogene-encoded KDM4E, may be sensitive to changing oxygen concentrations. Here, we report detailed analysis of the effect of oxygen availability on the activity of the KDM4 subfamily member KDM4A, importantly demonstrating a high level of O2 sensitivity both with isolated protein and in cells. Kinetic analysis of the recombinant enzyme revealed a high KMapp(O2) of 173 ± 23 μM, indicating that the activity of the enzyme is able to respond sensitively to a reduction in oxygen concentration. Furthermore, immunofluorescence experiments in U2OS cells conditionally overexpressing KDM4A showed that the cellular activity of KDM4A against its primary substrate, H3K9me3, displayed a graded response to depleting oxygen concentrations in line with the data obtained using isolated protein. These results suggest that KDM4A possesses the potential to act as an oxygen sensor in the context of chromatin modifications, with possible implications for epigenetic regulation in hypoxic disease states. Importantly, this correlation between the oxygen sensitivity of the catalytic activity of KDM4A in biochemical and cellular assays demonstrates the utility of biochemical studies in understanding the factors contributing to the diverse biological functions and varied activity of the 2OG oxygenases.
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Affiliation(s)
- Rebecca
L Hancock
- Chemistry
Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
- Radcliffe
Department of Medicine, Division of Cardiovascular Medicine, BHF Centre of Research Excellence, Wellcome Trust
Centre for Human Genetics, Roosevelt Drive, Oxford OX3 7BN, United Kingdom
| | - Norma Masson
- Target Discovery Institute, NDM Research Building, University
of Oxford, Roosevelt
Drive, Oxford OX3 7BN, United Kingdom
| | - Kate Dunne
- Chemistry
Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
- Radcliffe
Department of Medicine, Division of Cardiovascular Medicine, BHF Centre of Research Excellence, Wellcome Trust
Centre for Human Genetics, Roosevelt Drive, Oxford OX3 7BN, United Kingdom
| | - Emily Flashman
- Chemistry
Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Akane Kawamura
- Chemistry
Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
- Radcliffe
Department of Medicine, Division of Cardiovascular Medicine, BHF Centre of Research Excellence, Wellcome Trust
Centre for Human Genetics, Roosevelt Drive, Oxford OX3 7BN, United Kingdom
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LncRNA AK023948 is a positive regulator of AKT. Nat Commun 2017; 8:14422. [PMID: 28176758 PMCID: PMC5309785 DOI: 10.1038/ncomms14422] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 12/28/2016] [Indexed: 12/12/2022] Open
Abstract
Despite the overwhelming number of human long non-coding RNAs (lncRNAs) reported so far, little is known about their physiological functions for the majority of them. The present study uses a CRISPR/Cas9-based synergistic activation mediator (SAM) system to identify potential lncRNAs capable of regulating AKT activity. Among lncRNAs identified from this screen, we demonstrate that AK023948 is a positive regulator for AKT. Knockout of AK023948 suppresses, whereas rescue with AK023948 restores the AKT activity. Mechanistically, AK023948 functionally interacts with DHX9 and p85. Importantly, AK023948 is required for the interaction between DHX9 and p85 to hence the p85 stability and promote AKT activity. Finally, AK023948 is upregulated in breast cancer; interrogation of TCGA data set indicates that upregulation of DHX9 in breast cancer is associated with poor survival. Together, this study demonstrates two previously uncharacterized factors AK023948 and DHX9 as important players in the AKT pathway, and that their upregulation may contribute to breast tumour progression. The function of many human long non-coding RNAs (lncRNAs) is still undetermined. Here, the authors setup a gain of function CRISPR-based screen and identify a lncRNA that positively regulates AKT activity by interacting with the RNA helicase DHX9 resulting in stabilization of PI3K regulatory subunit p85.
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Chen X, Li T, Wang X, Du Z, Liu R, Yang Y. Synthetic dual-input mammalian genetic circuits enable tunable and stringent transcription control by chemical and light. Nucleic Acids Res 2015; 44:2677-90. [PMID: 26673714 PMCID: PMC4824083 DOI: 10.1093/nar/gkv1343] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 11/18/2015] [Indexed: 12/21/2022] Open
Abstract
Programmable transcription factors can enable precise control of gene expression triggered by a chemical inducer or light. To obtain versatile transgene system with combined benefits of a chemical inducer and light inducer, we created various chimeric promoters through the assembly of different copies of the tet operator and Gal4 operator module, which simultaneously responded to a tetracycline-responsive transcription factor and a light-switchable transactivator. The activities of these chimeric promoters can be regulated by tetracycline and blue light synergistically or antagonistically. Further studies of the antagonistic genetic circuit exhibited high spatiotemporal resolution and extremely low leaky expression, which therefore could be used to spatially and stringently control the expression of highly toxic protein Diphtheria toxin A for light regulated gene therapy. When transferring plasmids engineered for the gene switch-driven expression of a firefly luciferase (Fluc) into mice, the Fluc expression levels of the treated animals directly correlated with the tetracycline and light input program. We suggest that dual-input genetic circuits using TET and light that serve as triggers to achieve expression profiles may enable the design of robust therapeutic gene circuits for gene- and cell-based therapies.
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Affiliation(s)
- Xianjun Chen
- Synthetic Biology and Biotechnology Laboratory, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China Optogenetics & Molecular Imaging Interdisciplinary Research Center, CAS Center for Excellence in Brain Science, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
| | - Ting Li
- Synthetic Biology and Biotechnology Laboratory, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China Optogenetics & Molecular Imaging Interdisciplinary Research Center, CAS Center for Excellence in Brain Science, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
| | - Xue Wang
- Synthetic Biology and Biotechnology Laboratory, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
| | - Zengmin Du
- Synthetic Biology and Biotechnology Laboratory, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China Optogenetics & Molecular Imaging Interdisciplinary Research Center, CAS Center for Excellence in Brain Science, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
| | - Renmei Liu
- Synthetic Biology and Biotechnology Laboratory, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China Optogenetics & Molecular Imaging Interdisciplinary Research Center, CAS Center for Excellence in Brain Science, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
| | - Yi Yang
- Synthetic Biology and Biotechnology Laboratory, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China Optogenetics & Molecular Imaging Interdisciplinary Research Center, CAS Center for Excellence in Brain Science, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China Collaborative Innovation Center of Genetics and Development, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
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40
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Moss Bendtsen K, Jensen MH, Krishna S, Semsey S. The role of mRNA and protein stability in the function of coupled positive and negative feedback systems in eukaryotic cells. Sci Rep 2015; 5:13910. [PMID: 26365394 PMCID: PMC4568459 DOI: 10.1038/srep13910] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Accepted: 08/03/2015] [Indexed: 11/25/2022] Open
Abstract
Oscillators and switches are important elements of regulation in biological systems. These are composed of coupling negative feedback loops, which cause oscillations when delayed, and positive feedback loops, which lead to memory formation. Here, we examine the behavior of a coupled feedback system, the Negative Autoregulated Frustrated bistability motif (NAF). This motif is a combination of two previously explored motifs, the frustrated bistability motif (FBM) and the negative auto regulation motif (NAR), which both can produce oscillations. The NAF motif was previously suggested to govern long term memory formation in animals, and was used as a synthetic oscillator in bacteria. We build a mathematical model to analyze the dynamics of the NAF motif. We show analytically that the NAF motif requires an asymmetry in the strengths of activation and repression links in order to produce oscillations. We show that the effect of time delays in eukaryotic cells, originating from mRNA export and protein import, are negligible in this system. Based on the reported protein and mRNA half-lives in eukaryotic cells, we find that even though the NAF motif possesses the ability for oscillations, it mostly promotes constant protein expression at the biologically relevant parameter regimes.
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Affiliation(s)
- Kristian Moss Bendtsen
- University of Copenhagen, Niels Bohr Institute, Blegdamsvej 17, DK-2100 Copenhagen, Denmark
| | - Mogens H Jensen
- University of Copenhagen, Niels Bohr Institute, Blegdamsvej 17, DK-2100 Copenhagen, Denmark
| | - Sandeep Krishna
- University of Copenhagen, Niels Bohr Institute, Blegdamsvej 17, DK-2100 Copenhagen, Denmark.,Simons Centre for the Study of Living Machines, National Center for Biological Sciences, GKVK Campus, Bellary Road, Bangalore 560065, India
| | - Szabolcs Semsey
- University of Copenhagen, Niels Bohr Institute, Blegdamsvej 17, DK-2100 Copenhagen, Denmark
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41
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Synthetic Biology--Toward Therapeutic Solutions. J Mol Biol 2015; 428:945-62. [PMID: 26334368 DOI: 10.1016/j.jmb.2015.08.020] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 08/18/2015] [Accepted: 08/19/2015] [Indexed: 02/07/2023]
Abstract
Higher multicellular organisms have evolved sophisticated intracellular and intercellular biological networks that enable cell growth and survival to fulfill an organism's needs. Although such networks allow the assembly of complex tissues and even provide healing and protective capabilities, malfunctioning cells can have severe consequences for an organism's survival. In humans, such events can result in severe disorders and diseases, including metabolic and immunological disorders, as well as cancer. Dominating the therapeutic frontier for these potentially lethal disorders, cell and gene therapies aim to relieve or eliminate patient suffering by restoring the function of damaged, diseased, and aging cells and tissues via the introduction of healthy cells or alternative genes. However, despite recent success, these efforts have yet to achieve sufficient therapeutic effects, and further work is needed to ensure the safe and precise control of transgene expression and cellular processes. In this review, we describe the biological tools and devices that are at the forefront of synthetic biology and discuss their potential to advance the specificity, efficiency, and safety of the current generation of cell and gene therapies, including how they can be used to confer curative effects that far surpass those of conventional therapeutics. We also highlight the current therapeutic delivery tools and the current limitations that hamper their use in human applications.
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42
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Berens C, Bisle S, Klingenbeck L, Lührmann A. Applying an Inducible Expression System to Study Interference of Bacterial Virulence Factors with Intracellular Signaling. J Vis Exp 2015:e52903. [PMID: 26168006 DOI: 10.3791/52903] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The technique presented here allows one to analyze at which step a target protein, or alternatively a small molecule, interacts with the components of a signaling pathway. The method is based, on the one hand, on the inducible expression of a specific protein to initiate a signaling event at a defined and predetermined step in the selected signaling cascade. Concomitant expression, on the other hand, of the gene of interest then allows the investigator to evaluate if the activity of the expressed target protein is located upstream or downstream of the initiated signaling event, depending on the readout of the signaling pathway that is obtained. Here, the apoptotic cascade was selected as a defined signaling pathway to demonstrate protocol functionality. Pathogenic bacteria, such as Coxiella burnetii, translocate effector proteins that interfere with host cell death induction in the host cell to ensure bacterial survival in the cell and to promote their dissemination in the organism. The C. burnetii effector protein CaeB effectively inhibits host cell death after induction of apoptosis with UV-light or with staurosporine. To narrow down at which step CaeB interferes with the propagation of the apoptotic signal, selected proteins with well-characterized pro-apoptotic activity were expressed transiently in a doxycycline-inducible manner. If CaeB acts upstream of these proteins, apoptosis will proceed unhindered. If CaeB acts downstream, cell death will be inhibited. The test proteins selected were Bax, which acts at the level of the mitochondria, and caspase 3, which is the major executioner protease. CaeB interferes with cell death induced by Bax expression, but not by caspase 3 expression. CaeB, thus, interacts with the apoptotic cascade between these two proteins.
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Affiliation(s)
- Christian Berens
- Department Biologie, Friedrich-Alexander-Universität; Institut für Molekulare Pathogenese, Friedrich-Loeffler-Institut
| | - Stephanie Bisle
- Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen
| | - Leonie Klingenbeck
- Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen
| | - Anja Lührmann
- Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen;
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43
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Single-cell analysis reveals heterogeneity in onset of transgene expression from synthetic tetracycline-dependent promoters. Biotechnol J 2015; 10:323-31. [DOI: 10.1002/biot.201400076] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 12/18/2014] [Accepted: 01/12/2015] [Indexed: 12/12/2022]
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44
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Tsai CS, Kwak S, Turner TL, Jin YS. Yeast synthetic biology toolbox and applications for biofuel production. FEMS Yeast Res 2015; 15:1-15. [PMID: 25195615 DOI: 10.1111/1567-1364.12206] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 06/16/2014] [Accepted: 08/31/2014] [Indexed: 01/04/2023] Open
Abstract
Yeasts are efficient biofuel producers with numerous advantages outcompeting bacterial counterparts. While most synthetic biology tools have been developed and customized for bacteria especially for Escherichia coli, yeast synthetic biological tools have been exploited for improving yeast to produce fuels and chemicals from renewable biomass. Here we review the current status of synthetic biological tools and their applications for biofuel production, focusing on the model strain Saccharomyces cerevisiae We describe assembly techniques that have been developed for constructing genes, pathways, and genomes in yeast. Moreover, we discuss synthetic parts for allowing precise control of gene expression at both transcriptional and translational levels. Applications of these synthetic biological approaches have led to identification of effective gene targets that are responsible for desirable traits, such as cellulosic sugar utilization, advanced biofuel production, and enhanced tolerance against toxic products for biofuel production from renewable biomass. Although an array of synthetic biology tools and devices are available, we observed some gaps existing in tool development to achieve industrial utilization. Looking forward, future tool development should focus on industrial cultivation conditions utilizing industrial strains.
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Affiliation(s)
- Ching-Sung Tsai
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Suryang Kwak
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Timothy L Turner
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Yong-Su Jin
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA .,Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, USA
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45
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Abstract
Engineered transcription activator-like effectors, or TALEs, have emerged as a new class of designer DNA-binding proteins. Their DNA recognition sites can be specified with great flexibility. When fused to appropriate transcriptional regulatory domains, they can serve as designer transcription factors, modulating the activity of targeted promoters. We created tet operator (tetO)-specific TALEs (tetTALEs), with an identical DNA-binding site as the Tet repressor (TetR) and the TetR-based transcription factors that are extensively used in eukaryotic transcriptional control systems. Different constellations of tetTALEs and tetO modified chromosomal transcription units were analyzed for their efficacy in mammalian cells. We find that tetTALE-silencers can entirely abrogate expression from the strong human EF1α promoter when binding upstream of the transcriptional control sequence. Remarkably, the DNA-binding domain of tetTALE alone can effectively counteract trans-activation mediated by the potent tettrans-activator and also directly interfere with RNA polymerase II transcription initiation from the strong CMV promoter. Our results demonstrate that TALEs can act as highly versatile tools in genetic engineering, serving as trans-activators, trans-silencers and also competitive repressors.
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Affiliation(s)
- Jeannette Werner
- Helmholtz-Zentrum Geesthacht (HZG), Institute of Biomaterial Science, Teltow 14513, Germany Max Delbrück Center for Molecular Medicine, Berlin 13125, Germany Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Föhrer Strasse 15, 13353 Berlin, Germany
| | - Manfred Gossen
- Helmholtz-Zentrum Geesthacht (HZG), Institute of Biomaterial Science, Teltow 14513, Germany Max Delbrück Center for Molecular Medicine, Berlin 13125, Germany Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Föhrer Strasse 15, 13353 Berlin, Germany
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46
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Rodgers MJ, Banks DJ, Bradley KA, Young JA. CHD1 and CHD2 are positive regulators of HIV-1 gene expression. Virol J 2014; 11:180. [PMID: 25297984 PMCID: PMC4283154 DOI: 10.1186/1743-422x-11-180] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Accepted: 09/24/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Retroviruses encode a very limited number of proteins and therefore must exploit a wide variety of host proteins for completion of their lifecycle. METHODS We performed an insertional mutagenesis screen to identify novel cellular regulators of retroviral replication. RESULTS This approach identified the ATP-dependent chromatin remodeler, chromodomain helicase DNA-binding protein 2 (CHD2), as well as the highly related CHD1 protein, as positive regulators of both MLV and HIV-1 replication in rodent and human cells. RNAi knockdown of either CHD2 or the related CHD1 protein, in human cells resulted in a block to infection by HIV-1, specifically at the level of transcription. CONCLUSIONS These results demonstrate that CHD1 and CHD2 can act as positive regulators of HIV-1 gene expression.
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Affiliation(s)
| | | | | | - John At Young
- The Nomis Center for Immunobiology and Microbial Pathogenesis, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
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Le Guiner C, Stieger K, Toromanoff A, Guilbaud M, Mendes-Madeira A, Devaux M, Guigand L, Cherel Y, Moullier P, Rolling F, Adjali O. Transgene regulation using the tetracycline-inducible TetR-KRAB system after AAV-mediated gene transfer in rodents and nonhuman primates. PLoS One 2014; 9:e102538. [PMID: 25248159 PMCID: PMC4172479 DOI: 10.1371/journal.pone.0102538] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 06/19/2014] [Indexed: 11/19/2022] Open
Abstract
Numerous studies have demonstrated the efficacy of the Adeno-Associated Virus (AAV)-based gene delivery platform in vivo. The control of transgene expression in many protocols is highly desirable for therapeutic applications and/or safety reasons. To date, the tetracycline and the rapamycin dependent regulatory systems have been the most widely evaluated. While the long-term regulation of the transgene has been obtained in rodent models, the translation of these studies to larger animals, especially to nonhuman primates (NHP), has often resulted in an immune response against the recombinant regulator protein involved in transgene expression regulation. These immune responses were dependent on the target tissue and vector delivery route. Here, using AAV vectors, we evaluated a doxycyclin-inducible system in rodents and macaques in which the TetR protein is fused to the human Krüppel associated box (KRAB) protein. We demonstrated long term gene regulation efficiency in rodents after subretinal and intramuscular administration of AAV5 and AAV1 vectors, respectively. However, as previously described for other chimeric transactivators, the TetR-KRAB-based system failed to achieve long term regulation in the macaque after intramuscular vector delivery because of the development of an immune response. Thus, immunity against the chimeric transactivator TetR-KRAB emerged as the primary limitation for the clinical translation of the system when targeting the skeletal muscle, as previously described for other regulatory proteins. New developments in the field of chimeric drug-sensitive transactivators with the potential to not trigger the host immune system are still needed.
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Affiliation(s)
- Caroline Le Guiner
- INSERM UMR 1089, Atlantic Gene Therapies, Nantes University Hospital, Nantes, France
| | - Knut Stieger
- INSERM UMR 1089, Atlantic Gene Therapies, Nantes University Hospital, Nantes, France
- Department of Ophthalmology, Faculty of Medicine, Justus-Liebig-University Giessen, Giessen, Germany
| | - Alice Toromanoff
- INSERM UMR 1089, Atlantic Gene Therapies, Nantes University Hospital, Nantes, France
| | - Mickaël Guilbaud
- INSERM UMR 1089, Atlantic Gene Therapies, Nantes University Hospital, Nantes, France
| | | | - Marie Devaux
- INSERM UMR 1089, Atlantic Gene Therapies, Nantes University Hospital, Nantes, France
| | - Lydie Guigand
- INRA UMR 703 and Atlantic Gene Therapies, ONIRIS, Nantes, France
| | - Yan Cherel
- INRA UMR 703 and Atlantic Gene Therapies, ONIRIS, Nantes, France
| | - Philippe Moullier
- INSERM UMR 1089, Atlantic Gene Therapies, Nantes University Hospital, Nantes, France
- Department of Molecular Genetics and Microbiology department, University of Florida, Gainesville, Florida, United States of America
| | - Fabienne Rolling
- INSERM UMR 1089, Atlantic Gene Therapies, Nantes University Hospital, Nantes, France
| | - Oumeya Adjali
- INSERM UMR 1089, Atlantic Gene Therapies, Nantes University Hospital, Nantes, France
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Brinkman AM, Wu J, Ersland K, Xu W. Estrogen receptor α and aryl hydrocarbon receptor independent growth inhibitory effects of aminoflavone in breast cancer cells. BMC Cancer 2014; 14:344. [PMID: 24885022 PMCID: PMC4037283 DOI: 10.1186/1471-2407-14-344] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Accepted: 04/23/2014] [Indexed: 11/13/2022] Open
Abstract
Background Numerous studies have implicated the aryl hydrocarbon receptor (AhR) as a potential therapeutic target for several human diseases, including estrogen receptor alpha (ERα) positive breast cancer. Aminoflavone (AF), an activator of AhR signaling, is currently undergoing clinical evaluation for the treatment of solid tumors. Of particular interest is the potential treatment of triple negative breast cancers (TNBC), which are typically more aggressive and characterized by poorer outcomes. Here, we examined AF’s effects on two TNBC cell lines and the role of AhR signaling in AF sensitivity in these model cell lines. Methods AF sensitivity in MDA-MB-468 and Cal51 was examined using cell counting assays to determine growth inhibition (GI50) values. Luciferase assays and qPCR of AhR target genes cytochrome P450 (CYP) 1A1 and 1B1 were used to confirm AF-mediated AhR signaling. The requirement of endogenous levels of AhR and AhR signaling for AF sensitivity was examined in MDA-MB-468 and Cal51 cells stably harboring inducible shRNA for AhR. The mechanism of AF-mediated growth inhibition was explored using flow cytometry for markers of DNA damage and apoptosis, cell cycle analysis, and β-galactosidase staining for senescence. Luciferase data was analyzed using Student’s T test. Three-parameter nonlinear regression was performed for cell counting assays. Results Here, we report that ERα-negative TNBC cell lines MDA-MB-468 and Cal51 are sensitive to AF. Further, we presented evidence suggesting that neither endogenous AhR expression levels nor downstream induction of AhR target genes CYP1A1 and CYP1B1 is required for AF-mediated growth inhibition in these cells. Between these two ERα negative cell lines, we showed that the mechanism of AF action differs slightly. Low dose AF mediated DNA damage, S-phase arrest and apoptosis in MDA-MB-468 cells, while it resulted in DNA damage, S-phase arrest and cellular senescence in Cal51 cells. Conclusions Overall, this work provides evidence against the simplified view of AF sensitivity, and suggests that AF could mediate growth inhibitory effects in ERα-positive and negative breast cancer cells, as well as cells with impaired AhR expression and signaling. While AF could have therapeutic effects on broader subtypes of breast cancer, the mechanism of cytotoxicity is complex, and likely, cell line- and tumor-specific.
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Affiliation(s)
| | | | | | - Wei Xu
- Molecular and Environmental Toxicology Center, University of Wisconsin - Madison, Madison, WI, USA.
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49
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Development of a multipurpose GATEWAY-based lentiviral tetracycline-regulated conditional RNAi system (GLTR). PLoS One 2014; 9:e97764. [PMID: 24841113 PMCID: PMC4026376 DOI: 10.1371/journal.pone.0097764] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 04/24/2014] [Indexed: 01/08/2023] Open
Abstract
RNA interference (RNAi) has become an essential technology for functional gene analysis. Its success, however, depends on the effective expression of RNAi-inducing small double-stranded interfering RNA molecules (siRNAs) in target cells. In many cell types, RNAi can be achieved by transfection of chemically synthesised siRNAs, which results in transient knockdown of protein expression. Expression of double-stranded short hairpin RNA (shRNA) provides another means to induce RNAi in cells that are hard to transfect. To facilitate the generation of stable, conditional RNAi cell lines, we have developed novel one- and two-component vector GATEWAY-compatible lentiviral tetracycline-regulated RNAi (GLTR) systems. The combination of a modified RNA-polymerase-III-dependent H1 RNA promoter (designated ‘THT’) for conditional shRNA expression with different lentiviral delivery vectors allows (1) the use of fluorescent proteins for colour-coded combinatorial RNAi or for monitoring RNAi induction (pGLTR-FP), (2) selection of transduced cells (pGLTR-S), and (3) the generation of conditional cell lines using a one vector system (pGLTR-X). All three systems were found to be suitable for the analysis of essential genes, such as CDC27, a component of the mitotic ubiquitin ligase APC/C, in cell lines and primary human cells.
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50
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The B-subdomain of the Xenopus laevis XFIN KRAB-AB domain is responsible for its weaker transcriptional repressor activity compared to human ZNF10/Kox1. PLoS One 2014; 9:e87609. [PMID: 24498343 PMCID: PMC3912051 DOI: 10.1371/journal.pone.0087609] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 12/23/2013] [Indexed: 12/12/2022] Open
Abstract
The Krüppel-associated box (KRAB) domain interacts with the nuclear hub protein TRIM28 to initiate or mediate chromatin-dependent processes like transcriptional repression, imprinting or suppression of endogenous retroviruses. The prototype KRAB domain initially identified in ZNF10/KOX1 encompasses two subdomains A and B that are found in hundreds of zinc finger transcription factors studied in human and murine genomes. Here we demonstrate for the first time transcriptional repressor activity of an amphibian KRAB domain. After sequence correction, the updated KRAB-AB domain of zinc finger protein XFIN from the frog Xenopus laevis was found to confer transcriptional repression in reporter assays in Xenopus laevis A6 kidney cells as well as in human HeLa, but not in the minnow Pimephales promelas fish cell line EPC. Binding of the XFIN KRAB-AB domain to human TRIM28 was demonstrated in a classical co-immunoprecipitation approach and visualized in a single-cell compartmentalization assay. XFIN-AB displayed reduced potency in repression as well as lower strength of interaction with TRIM28 compared to ZNF10 KRAB-AB. KRAB-B subdomain swapping between the two KRAB domains indicated that it was mainly the KRAB-B subdomain of XFIN that was responsible for its lower capacity in repression and binding to human TRIM28. In EPC fish cells, ZNF10 and XFIN KRAB repressor activity could be partially restored to low levels by adding exogenous human TRIM28. In contrast to XFIN, we did not find any transcriptional repression activity for the KRAB-like domain of human PRDM9 in HeLa cells. PRDM9 is thought to harbor an evolutionary older domain related to KRAB whose homologs even occur in invertebrates. Our results support the notion that functional bona fide KRAB domains which confer transcriptional repression and interact with TRIM28 most likely co-evolved together with TRIM28 at the beginning of tetrapode evolution.
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