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Becskei A. Tuning up Transcription Factors for Therapy. Molecules 2020; 25:E1902. [PMID: 32326099 PMCID: PMC7221782 DOI: 10.3390/molecules25081902] [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: 02/28/2020] [Revised: 04/16/2020] [Accepted: 04/17/2020] [Indexed: 12/19/2022] Open
Abstract
The recent developments in the delivery and design of transcription factors put their therapeutic applications within reach, exemplified by cell replacement, cancer differentiation and T-cell based cancer therapies. The success of such applications depends on the efficacy and precision in the action of transcription factors. The biophysical and genetic characterization of the paradigmatic prokaryotic repressors, LacI and TetR and the designer transcription factors, transcription activator-like effector (TALE) and CRISPR-dCas9 revealed common principles behind their efficacy, which can aid the optimization of transcriptional activators and repressors. Further studies will be required to analyze the linkage between dissociation constants and enzymatic activity, the role of phase separation and squelching in activation and repression and the long-range interaction of transcription factors with epigenetic regulators in the context of the chromosomes. Understanding these mechanisms will help to tailor natural and synthetic transcription factors to the needs of specific applications.
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Affiliation(s)
- Attila Becskei
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
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52
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C/EBPβ is a critical mediator of IFN-α-induced exhaustion of chronic myeloid leukemia stem cells. Blood Adv 2020; 3:476-488. [PMID: 30755436 DOI: 10.1182/bloodadvances.2018020503] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Accepted: 01/12/2019] [Indexed: 11/20/2022] Open
Abstract
Even in the era of ABL tyrosine kinase inhibitors, eradication of chronic myeloid leukemia (CML) stem cells is necessary for complete cure of the disease. Interferon-α (IFN-α) has long been used for the treatment of chronic-phase CML, but its mechanisms of action against CML stem cells remain unclear. We found that IFN-α upregulated CCAAT/enhancer binding protein β (C/EBPβ) in BCR-ABL-expressing mouse cells by activating STAT1 and STAT5, which were recruited to a newly identified 3' distal enhancer of Cebpb that contains tandemly aligned IFN-γ-activated site elements. Suppression or deletion of the IFN-γ-activated site elements abrogated IFN-α-dependent upregulation of C/EBPβ. IFN-α induced differentiation and exhaustion of CML stem cells, both in vitro and in vivo, in a C/EBPβ-dependent manner. In addition, IFN-α upregulated C/EBPβ and induced exhaustion of lineage- CD34+ cells from CML patients. Collectively, these results clearly indicate that C/EBPβ is a critical mediator of IFN-α-induced differentiation and exhaustion of CML stem cells.
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53
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Barrett CM, McCracken R, Elmer J, Haynes KA. Components from the Human c-myb Transcriptional Regulation System Reactivate Epigenetically Repressed Transgenes. Int J Mol Sci 2020; 21:E530. [PMID: 31947658 PMCID: PMC7014047 DOI: 10.3390/ijms21020530] [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: 11/11/2019] [Revised: 01/07/2020] [Accepted: 01/07/2020] [Indexed: 11/16/2022] Open
Abstract
A persistent challenge for mammalian cell engineering is the undesirable epigenetic silencing of transgenes. Foreign DNA can be incorporated into closed chromatin before and after it has been integrated into a host cell's genome. To identify elements that mitigate epigenetic silencing, we tested components from the c-myb and NF-kB transcriptional regulation systems in transiently transfected DNA and at chromosomally integrated transgenes in PC-3 and HEK 293 cells. DNA binding sites for MYB (c-myb) placed upstream of a minimal promoter enhanced expression from transiently transfected plasmid DNA. We targeted p65 and MYB fusion proteins to a chromosomal transgene, UAS-Tk-luciferase, that was silenced by ectopic Polycomb chromatin complexes. Transient expression of Gal4-MYB induced an activated state that resisted complete re-silencing. We used custom guide RNAs and dCas9-MYB to target MYB to different positions relative to the promoter and observed that transgene activation within ectopic Polycomb chromatin required proximity of dCas9-MYB to the transcriptional start site. Our report demonstrates the use of MYB in the context of the CRISPR-activation system, showing that DNA elements and fusion proteins derived from c-myb can mitigate epigenetic silencing to improve transgene expression in engineered cell lines.
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Affiliation(s)
- Cassandra M. Barrett
- School of Biological and Health Systems Engineering, Arizona State University, 501 East Tyler Mall, Tempe, AZ 85287, USA;
| | - Reilly McCracken
- Department of Chemical Engineering, Villanova University, 217 White Hall, 800 East Lancaster Avenue, Villanova, PA 19085, USA; (R.M.); (J.E.)
| | - Jacob Elmer
- Department of Chemical Engineering, Villanova University, 217 White Hall, 800 East Lancaster Avenue, Villanova, PA 19085, USA; (R.M.); (J.E.)
| | - Karmella A. Haynes
- School of Biological and Health Systems Engineering, Arizona State University, 501 East Tyler Mall, Tempe, AZ 85287, USA;
- Wallace H. Coulter Department of Biomedical Engineering, Emory University, Atlanta, GA 30322, USA
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54
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Moradpour M, Abdulah SNA. CRISPR/dCas9 platforms in plants: strategies and applications beyond genome editing. PLANT BIOTECHNOLOGY JOURNAL 2020; 18:32-44. [PMID: 31392820 PMCID: PMC6920162 DOI: 10.1111/pbi.13232] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 07/27/2019] [Accepted: 07/30/2019] [Indexed: 05/19/2023]
Abstract
Clustered regularly interspaced short palindromic repeat (CRISPR) and Cas9-associated protein systems provide a powerful genetic manipulation tool that can drive plant research forward. Nuclease-dead Cas9 (dCas9) is an enzymatically inactive mutant of Cas9 in which its endonuclease activity is non-functional. The applications of CRISPR/dCas9 have expanded and diversified in recent years. Originally, dCas9 was used as a CRISPR/Cas9 re-engineering tool that enables targeted expression of any gene or multiple genes through recruitment of transcriptional effector domains without introducing irreversible DNA-damaging mutations. Subsequent applications have made use of its ability to recruit modifying enzymes and reporter proteins to DNA target sites. In this paper, the most recent progress in the applications of CRISPR/dCas9 in plants, which include gene activation and repression, epigenome editing, modulation of chromatin topology, live-cell chromatin imaging and DNA-free genetic modification, will be reviewed. The associated strategies for exploiting the CRISPR/dCas9 system for crop improvement with a dimer of the future of the CRISPR/dCas9 system in the functional genomics of crops and the development of traits will be briefly discussed.
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Affiliation(s)
- Mahdi Moradpour
- Laboratory of Science and TechnologyInstitute of Plantation StudiesUniversiti Putra MalaysiaSerdangSelangorMalaysia
| | - Siti Nor Akmar Abdulah
- Laboratory of Science and TechnologyInstitute of Plantation StudiesUniversiti Putra MalaysiaSerdangSelangorMalaysia
- Department of Agricultural TechnologyFaculty of AgricultureUniversiti Putra MalaysiaSerdangSelangorMalaysia
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55
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Ye W, Liu T, Zhu M, Zhang W, Huang Z, Li S, Li H, Kong Y, Chen Y. An Easy and Efficient Strategy for the Enhancement of Epothilone Production Mediated by TALE-TF and CRISPR/dcas9 Systems in Sorangium cellulosum. Front Bioeng Biotechnol 2019; 7:334. [PMID: 32039165 PMCID: PMC6988809 DOI: 10.3389/fbioe.2019.00334] [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: 06/26/2019] [Accepted: 10/30/2019] [Indexed: 11/23/2022] Open
Abstract
Epothilones are a kind of macrolides with strong cytotoxicity toward cancer cells and relatively lower side effects compared with taxol. Epothilone B derivate ixabepilone has been used for the clinical treatment of advanced breast cancer. However, the low yield of epothilones and the difficulty in the genetic manipulation of Sorangium cellulosum limited their wider application. Transcription activator-like effectors-Trancriptional factor (TALE-TF)-VP64 and clustered regularly interspaced short palindromic repeats (CRISPR)/dCas9-VP64 have been demonstrated as effective systems for the transcriptional improvement. In this study, a promoter for the epothilone biosynthesis cluster was obtained and the function has been verified. The TALE-TF-VP64 and CRISPR/dcas9-VP64 target P3 promoter were electroporated into S. cellulosum strain So ce M4, and the transcriptional levels of epothilone biosynthesis-related genes were significantly upregulated. The yield of epothilone B was improved by 2.89- and 1.53-fold by the introduction of recombinant TALE-TF-VP64-P3 and dCas9-VP64-P3 elements into So ce M4, respectively. The epothilone D yield was also improved by 1.12- and 2.18-fold in recombinant dCas9-So ce M4 and TALE-VP64 strains, respectively. The transcriptional regulation mechanism of TALE-TF-VP64 and the competition mechanism with endogenous transcriptional factor were investigated by electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP), demonstrating the combination of the P3 promoter and TALE-TF element and the competition between TALE-TF and endogenous transcriptional protein. This is the first report on the transcriptional regulation of the epothilone biosynthetic gene cluster in S. cellulosum using the TALE-TF and dCas9-VP64 systems, and the regulatory mechanism of the TALE-TF system for epothilone biosynthesis in S. cellulosum was also firstly revealed, thus shedding light on the metabolic engineering of S. cellulosum to improve epothilone yields substantially and promoting the application of epothilones in the biomedical industry.
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Affiliation(s)
- Wei Ye
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Taomei Liu
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Muzi Zhu
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Weimin Zhang
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Zilei Huang
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Saini Li
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Haohua Li
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Yali Kong
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Yuchan Chen
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
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56
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Xia JH, Wei GH. Enhancer Dysfunction in 3D Genome and Disease. Cells 2019; 8:cells8101281. [PMID: 31635067 PMCID: PMC6830074 DOI: 10.3390/cells8101281] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 10/10/2019] [Accepted: 10/14/2019] [Indexed: 12/13/2022] Open
Abstract
Spatiotemporal patterns of gene expression depend on enhancer elements and other factors during individual development and disease progression. The rapid progress of high-throughput techniques has led to well-defined enhancer chromatin properties. Various genome-wide methods have revealed a large number of enhancers and the discovery of three-dimensional (3D) genome architecture showing the distant interacting mechanisms of enhancers that loop to target gene promoters. Whole genome sequencing projects directed at cancer have led to the discovery of substantial enhancer dysfunction in misregulating gene expression and in tumor initiation and progression. Results from genome-wide association studies (GWAS) combined with functional genomics analyses have elucidated the functional impacts of many cancer risk-associated variants that are enriched within the enhancer regions of chromatin. Risk variants dysregulate the expression of enhancer variant-associated genes via 3D genomic interactions. Moreover, these enhancer variants often alter the chromatin binding affinity for cancer-relevant transcription factors, which in turn leads to aberrant expression of the genes associated with cancer susceptibility. In this review, we investigate the extent to which these genetic regulatory circuits affect cancer predisposition and how the recent development of genome-editing methods have enabled the determination of the impacts of genomic variation and alteration on cancer phenotype, which will eventually lead to better management plans and treatment responses to human cancer in the clinic.
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Affiliation(s)
- Ji-Han Xia
- Biocenter Oulu, Faculty of Biochemistry and Molecular Medicine, University of Oulu, 90014 Oulu, Finland.
| | - Gong-Hong Wei
- Biocenter Oulu, Faculty of Biochemistry and Molecular Medicine, University of Oulu, 90014 Oulu, Finland.
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57
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Methylation content sensitive enzyme ddRAD (MCSeEd): a reference-free, whole genome profiling system to address cytosine/adenine methylation changes. Sci Rep 2019; 9:14864. [PMID: 31619715 PMCID: PMC6795852 DOI: 10.1038/s41598-019-51423-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 09/26/2019] [Indexed: 12/18/2022] Open
Abstract
Methods for investigating DNA methylation nowadays either require a reference genome and high coverage, or investigate only CG methylation. Moreover, no large-scale analysis can be performed for N6-methyladenosine (6 mA) at an affordable price. Here we describe the methylation content sensitive enzyme double-digest restriction-site-associated DNA (ddRAD) technique (MCSeEd), a reduced-representation, reference-free, cost-effective approach for characterizing whole genome methylation patterns across different methylation contexts (e.g., CG, CHG, CHH, 6 mA). MCSeEd can also detect genetic variations among hundreds of samples. MCSeEd is based on parallel restrictions carried out by combinations of methylation insensitive and sensitive endonucleases, followed by next-generation sequencing. Moreover, we present a robust bioinformatic pipeline (available at https://bitbucket.org/capemaster/mcseed/src/master/ ) for differential methylation analysis combined with single nucleotide polymorphism calling without or with a reference genome.
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58
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Olson A, Basukala B, Wong WW, Henderson AJ. Targeting HIV-1 proviral transcription. Curr Opin Virol 2019; 38:89-96. [PMID: 31473372 DOI: 10.1016/j.coviro.2019.07.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 07/29/2019] [Accepted: 07/30/2019] [Indexed: 12/13/2022]
Abstract
Despite the success of antiretroviral therapies, there is no cure for HIV-1 infection due to the establishment of a long-lived latent reservoir that fuels viral rebound upon treatment interruption. 'Shock-and-kill' strategies to diminish the latent reservoir have had modest impact on the reservoir leading to considerations of alternative approaches to target HIV-1 proviruses. This review explores approaches to target HIV-1 transcription as a way to block the provirus expression.
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Affiliation(s)
- Alex Olson
- Department of Medicine, Section of Infectious Diseases, Boston University School of Medicine, United States
| | - Binita Basukala
- Cell & Molecular Biology, Biology, Boston University, United States
| | - Wilson W Wong
- Biomedical Engineering, Boston University, United States
| | - Andrew J Henderson
- Department of Medicine, Section of Infectious Diseases, Boston University School of Medicine, United States.
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59
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Johnston AD, Simões-Pires CA, Thompson TV, Suzuki M, Greally JM. Functional genetic variants can mediate their regulatory effects through alteration of transcription factor binding. Nat Commun 2019; 10:3472. [PMID: 31375681 PMCID: PMC6677801 DOI: 10.1038/s41467-019-11412-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Accepted: 07/10/2019] [Indexed: 12/23/2022] Open
Abstract
Functional variants in the genome are usually identified by their association with local gene expression, DNA methylation or chromatin states. DNA sequence motif analysis and chromatin immunoprecipitation studies have provided indirect support for the hypothesis that functional variants alter transcription factor binding to exert their effects. In this study, we provide direct evidence that functional variants can alter transcription factor binding. We identify a multifunctional variant within the TBC1D4 gene encoding a canonical NFκB binding site, and edited it using CRISPR-Cas9 to remove this site. We show that this editing reduces TBC1D4 expression, local chromatin accessibility and binding of the p65 component of NFκB. We then used CRISPR without genomic editing to guide p65 back to the edited locus, demonstrating that this re-targeting, occurring ~182 kb from the gene promoter, is enough to restore the function of the locus, supporting the central role of transcription factors mediating the effects of functional variants.
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Affiliation(s)
- Andrew D Johnston
- Center for Epigenomics and Department of Genetics (Division of Genomics), Albert Einstein College of Medicine, 1301 Morris Park Avenue, Bronx, NY, 10461, USA
| | - Claudia A Simões-Pires
- Center for Epigenomics and Department of Genetics (Division of Genomics), Albert Einstein College of Medicine, 1301 Morris Park Avenue, Bronx, NY, 10461, USA
| | - Taylor V Thompson
- Center for Epigenomics and Department of Genetics (Division of Genomics), Albert Einstein College of Medicine, 1301 Morris Park Avenue, Bronx, NY, 10461, USA
| | - Masako Suzuki
- Center for Epigenomics and Department of Genetics (Division of Genomics), Albert Einstein College of Medicine, 1301 Morris Park Avenue, Bronx, NY, 10461, USA
| | - John M Greally
- Center for Epigenomics and Department of Genetics (Division of Genomics), Albert Einstein College of Medicine, 1301 Morris Park Avenue, Bronx, NY, 10461, USA.
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60
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Abstract
The prokaryote-derived CRISPR-Cas genome editing systems have transformed our ability to manipulate, detect, image and annotate specific DNA and RNA sequences in living cells of diverse species. The ease of use and robustness of this technology have revolutionized genome editing for research ranging from fundamental science to translational medicine. Initial successes have inspired efforts to discover new systems for targeting and manipulating nucleic acids, including those from Cas9, Cas12, Cascade and Cas13 orthologues. Genome editing by CRISPR-Cas can utilize non-homologous end joining and homology-directed repair for DNA repair, as well as single-base editing enzymes. In addition to targeting DNA, CRISPR-Cas-based RNA-targeting tools are being developed for research, medicine and diagnostics. Nuclease-inactive and RNA-targeting Cas proteins have been fused to a plethora of effector proteins to regulate gene expression, epigenetic modifications and chromatin interactions. Collectively, the new advances are considerably improving our understanding of biological processes and are propelling CRISPR-Cas-based tools towards clinical use in gene and cell therapies.
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Affiliation(s)
- Adrian Pickar-Oliver
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University, Durham, NC, USA
| | - Charles A Gersbach
- Department of Biomedical Engineering, Duke University, Durham, NC, USA.
- Center for Genomic and Computational Biology, Duke University, Durham, NC, USA.
- Department of Surgery, Duke University Medical Center, Durham, NC, USA.
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61
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Baumann V, Wiesbeck M, Breunig CT, Braun JM, Köferle A, Ninkovic J, Götz M, Stricker SH. Targeted removal of epigenetic barriers during transcriptional reprogramming. Nat Commun 2019; 10:2119. [PMID: 31073172 PMCID: PMC6509258 DOI: 10.1038/s41467-019-10146-8] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 04/23/2019] [Indexed: 02/07/2023] Open
Abstract
Master transcription factors have the ability to direct and reverse cellular identities, and consequently their genes must be subject to particular transcriptional control. However, it is unclear which molecular processes are responsible for impeding their activation and safeguarding cellular identities. Here we show that the targeting of dCas9-VP64 to the promoter of the master transcription factor Sox1 results in strong transcript and protein up-regulation in neural progenitor cells (NPCs). This gene activation restores lost neuronal differentiation potential, which substantiates the role of Sox1 as a master transcription factor. However, despite efficient transactivator binding, major proportions of progenitor cells are unresponsive to the transactivating stimulus. By combining the transactivation domain with epigenome editing we find that among a series of euchromatic processes, the removal of DNA methylation (by dCas9-Tet1) has the highest potential to increase the proportion of cells activating foreign master transcription factors and thus breaking down cell identity barriers.
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Affiliation(s)
- Valentin Baumann
- MCN Junior Research Group, Munich Center for Neurosciences, Ludwig-Maximilian-Universitaet, BioMedical Center, Grosshaderner Strasse 9, 82152, Planegg-Martinsried, Germany
- Graduate School of Systemic Neurosciences, Ludwig-Maximilians-University, 82152, Planegg-Martinsried, Germany
| | - Maximilian Wiesbeck
- MCN Junior Research Group, Munich Center for Neurosciences, Ludwig-Maximilian-Universitaet, BioMedical Center, Grosshaderner Strasse 9, 82152, Planegg-Martinsried, Germany
| | - Christopher T Breunig
- MCN Junior Research Group, Munich Center for Neurosciences, Ludwig-Maximilian-Universitaet, BioMedical Center, Grosshaderner Strasse 9, 82152, Planegg-Martinsried, Germany
| | - Julia M Braun
- MCN Junior Research Group, Munich Center for Neurosciences, Ludwig-Maximilian-Universitaet, BioMedical Center, Grosshaderner Strasse 9, 82152, Planegg-Martinsried, Germany
| | - Anna Köferle
- MCN Junior Research Group, Munich Center for Neurosciences, Ludwig-Maximilian-Universitaet, BioMedical Center, Grosshaderner Strasse 9, 82152, Planegg-Martinsried, Germany
| | - Jovica Ninkovic
- Neurogenesis and Regeneration, Institute of Stem Cell Research, Helmholtz Zentrum, German Research Center for Environmental Health, Grosshaderner Strasse 9, 82152, Planegg-Martinsried, Germany
- BioMedizinisches Centrum, Ludwig-Maximilian-Universität, Großhaderner Str. 9, 82152, Planegg-Martinsried, Germany
| | - Magdalena Götz
- BioMedizinisches Centrum, Ludwig-Maximilian-Universität, Großhaderner Str. 9, 82152, Planegg-Martinsried, Germany
- Institute of Stem Cell Research, Helmholtz Zentrum, German Research Center for Environmental Health, Grosshaderner Strasse 9, 82152, Planegg-Martinsried, Germany
| | - Stefan H Stricker
- MCN Junior Research Group, Munich Center for Neurosciences, Ludwig-Maximilian-Universitaet, BioMedical Center, Grosshaderner Strasse 9, 82152, Planegg-Martinsried, Germany.
- BioMedizinisches Centrum, Ludwig-Maximilian-Universität, Großhaderner Str. 9, 82152, Planegg-Martinsried, Germany.
- Epigenetic Engineering, Institute of Stem Cell Research, Helmholtz Zentrum, German Research Center for Environmental Health, Grosshaderner Strasse 9, Planegg-Martinsried, 82152, Germany.
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62
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Tadić V, Josipović G, Zoldoš V, Vojta A. CRISPR/Cas9-based epigenome editing: An overview of dCas9-based tools with special emphasis on off-target activity. Methods 2019; 164-165:109-119. [PMID: 31071448 DOI: 10.1016/j.ymeth.2019.05.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 04/29/2019] [Accepted: 05/02/2019] [Indexed: 02/06/2023] Open
Abstract
Molecular tools for gene regulation and epigenome editing consist of two main parts: the targeting moiety binding a specific genomic locus and the effector domain performing the editing or regulatory function. The advent of CRISPR-Cas9 technology enabled easy and flexible targeting of almost any locus by co-expression of a small sgRNA molecule, which is complementary to the target sequence and forms a complex with Cas9, directing it to that particular target. Here, we review strategies for recruitment of effector domains, used in gene regulation and epigenome editing, to the dCas9 DNA-targeting protein. To date, the most important CRISPR-Cas9 applications in gene regulation are CRISPR activation or interference, while epigenome editing focuses on targeted changes in DNA methylation and histone modifications. Several strategies for signal amplification by recruitment of multiple effector domains deserve special focus. While some approaches rely on altering the sgRNA molecule and extending it with aptamers for effector domain recruitment, others use modifications to the Cas9 protein by direct fusions with effector domains or by addition of an epitope tag, which also has the ability to bind multiple effector domains. A major barrier to the widespread use of CRISPR-Cas9 technology for therapeutic purposes is its off-target effect. We review efforts to enhance CRISPR-Cas9 specificity by selection of Cas9 orthologs from various bacterial species and their further refinement by introduction of beneficial mutations. The molecular tools available today enable a researcher to choose the best balance of targeting flexibility, activity amplification, delivery method and specificity.
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Affiliation(s)
- Vanja Tadić
- University of Zagreb, Faculty of Science, Department of Biology, Division of Molecular Biology, Horvatovac 102a, HR-10000 Zagreb, Croatia
| | - Goran Josipović
- University of Zagreb, Faculty of Science, Department of Biology, Division of Molecular Biology, Horvatovac 102a, HR-10000 Zagreb, Croatia
| | - Vlatka Zoldoš
- University of Zagreb, Faculty of Science, Department of Biology, Division of Molecular Biology, Horvatovac 102a, HR-10000 Zagreb, Croatia
| | - Aleksandar Vojta
- University of Zagreb, Faculty of Science, Department of Biology, Division of Molecular Biology, Horvatovac 102a, HR-10000 Zagreb, Croatia.
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63
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Khadempar S, Familghadakchi S, Motlagh RA, Farahani N, Dashtiahangar M, Rezaei H, Gheibi Hayat SM. CRISPR-Cas9 in genome editing: Its function and medical applications. J Cell Physiol 2019; 234:5751-5761. [PMID: 30362544 DOI: 10.1002/jcp.27476] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 09/04/2018] [Indexed: 12/22/2022]
Abstract
The targeted genome modification using RNA-guided nucleases is associated with several advantages such as a rapid, easy, and efficient method that not only provides the manipulation and alteration of genes and functional studies for researchers, but also increases their awareness of the molecular basis of the disease and development of new and targeted therapeutic approaches. Different techniques have been emerged so far as the molecular scissors mediating targeted genome editing including zinc finger nuclease, transcription activator-like effector nucleases, and clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9). CRISPR-Cas9 is a bacterial immune system against viruses in which the single-strand RNA-guided Cas9 nuclease is linked to the targeted complementary sequences to apply changes. The advances made in the transfer, modification, and emergence of specific solutions have led to the creation of different classes of CRISPR-Cas9. Since this robust tool is capable of direct correction of disease-causing mutations, its ability to treat genetic disorders has attracted the tremendous attention of researchers. Considering the reported cases of nonspecific targeting of Cas9 proteins, many studies focused on enhancing the Cas9 features. In this regard, significant advances have been made in choosing guide RNA, new enzymes and methods for identifying misplaced targeting. Here, we highlighted the history and various direct aspects of CRISPR-Cas9, such as precision in genomic targeting, system transfer and its control over correction events with its applications in future biological studies, and modern treatment of diseases.
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Affiliation(s)
- Saedeh Khadempar
- Departemant of Medical Genetics, Shahid Sadoughi University of Medical Science, Yazd, Iran
| | - Shokoufeh Familghadakchi
- Department of Clinical Biochemistry, School of Paramedicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Roozbeh Akbari Motlagh
- Department of Biochemistry and Molecular Biology, Faculty of Veterinary, Shahid Chamran University of Ahvaz, Ahvaz, Iran
| | - Najmeh Farahani
- Department of Genetics and Molecular Biology, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Maryam Dashtiahangar
- Department of Biology, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Hamzeh Rezaei
- Department of Clinical Biochemistry, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Seyed Mohammad Gheibi Hayat
- Department of Medical Biotechnology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
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64
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Gutiérrez-González M, Latorre Y, Zúñiga R, Aguillón JC, Molina MC, Altamirano C. Transcription factor engineering in CHO cells for recombinant protein production. Crit Rev Biotechnol 2019; 39:665-679. [PMID: 31030575 DOI: 10.1080/07388551.2019.1605496] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The continuous increase of approved biopharmaceutical products drives the development of more efficient recombinant protein expression systems. Chinese hamster ovary (CHO) cells are the mainstay for this purpose but have some drawbacks, such as low levels of expression. Several strategies have been applied to increase the productivity of CHO cells with different outcomes. Transcription factor (TF) engineering has emerged as an interesting and successful approach, as these proteins can act as master regulators; the expression and function of a TF can be controlled by small molecules, and it is possible to design tailored TFs and promoters with desired features. To date, the majority of studies have focused on the use of TFs with growth, metabolic, cell cycle or endoplasmic reticulum functions, although there is a trend to develop new, synthetic TFs. Moreover, new synthetic biological approaches are showing promising advances for the development of specific TFs, even with tailored ligand sensitivity. In this article, we summarize the strategies to increase recombinant protein expression by modulating and designing TFs and with advancements in synthetic biology. We also illustrate how this class of proteins can be used to develop more robust expression systems.
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Affiliation(s)
| | - Yesenia Latorre
- b Escuela de Ingeniería Bioquímica, Pontificia Universidad Católica de Valparaíso , Valparaíso , Chile
| | - Roberto Zúñiga
- a Centro de InmunoBiotecnología, Universidad de Chile , Santiago , Chile
| | | | | | - Claudia Altamirano
- b Escuela de Ingeniería Bioquímica, Pontificia Universidad Católica de Valparaíso , Valparaíso , Chile
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65
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Xu X, Gao J, Dai W, Wang D, Wu J, Wang J. Gene activation by a CRISPR-assisted trans enhancer. eLife 2019; 8:45973. [PMID: 30973327 PMCID: PMC6478495 DOI: 10.7554/elife.45973] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Accepted: 04/10/2019] [Indexed: 12/15/2022] Open
Abstract
The deactivated CRISPR/Cas9 (dCas9) is now the most widely used gene activator. However, current dCas9-based gene activators are still limited by their unsatisfactory activity. In this study, we developed a new strategy, the CRISPR-assisted trans enhancer, for activating gene expression at high efficiency by combining dCas9-VP64/sgRNA with the widely used strong CMV enhancer. In this strategy, CMV enhancer DNA was recruited to target genes in trans by two systems: dCas9-VP64/csgRNA-sCMV and dCas9-VP64-GAL4/sgRNA-UAS-CMV. The former recruited trans enhancer by annealing between two short complementary oligonucleotides at the ends of the sgRNA and trans enhancer. The latter recruited trans enhancer by binding between GAL4 fused to dCas9 and UAS sequence of trans enhancer. The trans enhancer activated gene transcription as the natural looped cis enhancer. The trans enhancer could activate both exogenous reporter genes and variant endogenous genes in various cells, with much higher activation efficiency than that of current dCas9 activators.
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Affiliation(s)
- Xinhui Xu
- State Key Laboratory of Bioelectronics, Southeast University, Nanjing, China
| | - Jinliang Gao
- State Key Laboratory of Bioelectronics, Southeast University, Nanjing, China
| | - Wei Dai
- State Key Laboratory of Bioelectronics, Southeast University, Nanjing, China
| | - Danyang Wang
- State Key Laboratory of Bioelectronics, Southeast University, Nanjing, China
| | - Jian Wu
- State Key Laboratory of Bioelectronics, Southeast University, Nanjing, China
| | - Jinke Wang
- State Key Laboratory of Bioelectronics, Southeast University, Nanjing, China
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66
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Role of OCT4 in cancer stem-like cells and chemotherapy resistance. Biochim Biophys Acta Mol Basis Dis 2019; 1866:165432. [PMID: 30904611 DOI: 10.1016/j.bbadis.2019.03.005] [Citation(s) in RCA: 107] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 02/07/2019] [Accepted: 03/17/2019] [Indexed: 02/06/2023]
Abstract
Cancer stem-like cells (CSCs) contribute to the tumorigenicity, progression, and chemoresistance of cancers. It is not known whether CSCs arise from normal stem cells or if they arise from differentiated cancer cells by acquiring self-renewal features. These CSCs share stem cell markers that normal stem cells express. There is a rising interest in octamer-binding transcription factor 4 (OCT4), one of the stem cell factors that are essential in embryogenesis and pluripotency. OCT4 is also overexpressed in CSCs of various cancers. Although the majority of the studies in CSCs reported a positive association between the expression of OCT4 and chemoresistance and an inverse correlation between OCT4 and clinical prognosis, there are studies rebuking these findings, possibly due to the sparsity of stem cells within tumors and the heterogeneity of tumors. In addition, post-translational modification of OCT4 affects its activity and warrants further investigation for its association with chemoresistance and prognosis.
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67
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Ho EYK, Cao Q, Gu M, Chan RWL, Wu Q, Gerstein M, Yip KY. Shaping the nebulous enhancer in the era of high-throughput assays and genome editing. Brief Bioinform 2019; 21:836-850. [PMID: 30895290 DOI: 10.1093/bib/bbz030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 02/15/2019] [Accepted: 02/26/2019] [Indexed: 01/22/2023] Open
Abstract
Since the 1st discovery of transcriptional enhancers in 1981, their textbook definition has remained largely unchanged in the past 37 years. With the emergence of high-throughput assays and genome editing, which are switching the paradigm from bottom-up discovery and testing of individual enhancers to top-down profiling of enhancer activities genome-wide, it has become increasingly evidenced that this classical definition has left substantial gray areas in different aspects. Here we survey a representative set of recent research articles and report the definitions of enhancers they have adopted. The results reveal that a wide spectrum of definitions is used usually without the definition stated explicitly, which could lead to difficulties in data interpretation and downstream analyses. Based on these findings, we discuss the practical implications and suggestions for future studies.
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Affiliation(s)
| | - Qin Cao
- Department of Computer Science and Engineering, The Chinese University of Hong Kong, Hong Kong
| | - Mengting Gu
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Ricky Wai-Lun Chan
- Department of Computer Science and Engineering, The Chinese University of Hong Kong, Hong Kong
| | - Qiong Wu
- Department of Computer Science and Engineering, The Chinese University of Hong Kong, Hong Kong.,School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong
| | - Mark Gerstein
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA.,Program in Computational Biology and Bioinformatics.,Department of Computer Science, Yale University, New Haven, Connecticut, USA
| | - Kevin Y Yip
- Department of Biomedical Engineering.,Department of Computer Science and Engineering, The Chinese University of Hong Kong, Hong Kong.,Hong Kong Bioinformatics Centre.,CUHK-BGI Innovation Institute of Trans-omics.,Hong Kong Institute of Diabetes and Obesity, The Chinese University of Hong Kong, Hong Kong
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68
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Zhao C, Wei S, Wang Y. A guide for drug inducible transcriptional activation with HIT systems. Methods Enzymol 2019; 621:69-86. [PMID: 31128790 DOI: 10.1016/bs.mie.2019.02.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Precise investigation and manipulation of gene function often require modulation in a controlled and dynamic manner. In this chapter, we describe the methods to apply HIT systems for drug inducible transcriptional activation or simultaneous activation and genome editing in human cells. Together with those for editing, which are described in another chapter, HIT systems herein provide a valuable toolbox toward many biological applications, especially when precision and dynamics are required for a functional perturbation.
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Affiliation(s)
- Chen Zhao
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
| | - Shixian Wei
- University of Chinese Academy of Sciences, Beijing, China
| | - Yu Wang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China; Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China.
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69
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Porter SN, Levine RM, Pruett-Miller SM. A Practical Guide to Genome Editing Using Targeted Nuclease Technologies. Compr Physiol 2019; 9:665-714. [PMID: 30873595 DOI: 10.1002/cphy.c180022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Genome engineering using programmable nucleases is a rapidly evolving technique that enables precise genetic manipulations within complex genomes. Although this technology first surfaced with the creation of meganucleases, zinc finger nucleases, and transcription activator-like effector nucleases, CRISPR-Cas9 has been the most widely adopted platform because of its ease of use. This comprehensive review presents a basic overview of genome engineering and discusses the major technological advances in the field. In addition to nucleases, we discuss CRISPR-derived base editors and epigenetic modifiers. We also delve into practical applications of these tools, including creating custom-edited cell and animal models as well as performing genetic screens. Finally, we discuss the potential for therapeutic applications and ethical considerations related to employing this technology in humans. © 2019 American Physiological Society. Compr Physiol 9:665-714, 2019.
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Affiliation(s)
- Shaina N Porter
- Department of Cell & Molecular Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Rachel M Levine
- Department of Cell & Molecular Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Shondra M Pruett-Miller
- Department of Cell & Molecular Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
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70
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Zhang J, Gao X, Yang J, Fan X, Wang W, Liang Y, Fan L, Han H, Xu X, Tang F, Bao S, Liu P, Li X. Xist Intron 1 Repression by Transcriptional-Activator-Like Effectors Designer Transcriptional Factor Improves Somatic Cell Reprogramming in Mice. Stem Cells 2019; 37:599-608. [PMID: 30353613 DOI: 10.1002/stem.2928] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 07/06/2018] [Accepted: 08/18/2018] [Indexed: 11/11/2022]
Abstract
Xist is the master regulator of X chromosome inactivation. In order to further understand the Xist locus in the reprogramming of somatic cells to induced pluripotent stem cells (iPSCs) and in somatic cell nuclear transfer (SCNT), we tested transcription-activator-like effectors-based designer transcriptional factors (dTFs), which were specific to numerous regions at the Xist locus. We report that the selected dTF repressor 6 (R6) binding the intron 1 of Xist, which caused higher H3K9me3 followed by X chromosome opening and repression of X-linked genes in mouse embryonic fibroblasts, rather than affecting Xist expression, substantially improved the iPSC generation and the SCNT preimplantation embryo development. Conversely, the dTF activator targeting the same genomic region of R6 decreased iPSC formation and blocked SCNT-embryo development. These results thus uncover the critical requirement for the Xist locus in epigenetic resetting, which is not directly related to Xist transcription. This may provide a unique route to improving the reprogramming. Stem Cells 2019;37:599-608.
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Affiliation(s)
- Jindun Zhang
- Research Center for Animal Genetic Resources of Mongolian Plateau, Inner Mongolia University, Hohhot, People's Republic of China.,Wellcome Trust Sanger Institute, Cambridge, United Kingdom.,Inner Mongolia Saikexing Institute of Breeding and Reproductive Biotechnology in Domestic Animal, Hohhot, People's Republic of China
| | - Xuefei Gao
- Wellcome Trust Sanger Institute, Cambridge, United Kingdom
| | - Jian Yang
- Wellcome Trust Sanger Institute, Cambridge, United Kingdom
| | - Xiaoying Fan
- Biodynamic Optical Imaging Center (BIOPIC), Peking University, Beijing, People's Republic of China.,College of Life Sciences, Peking University, Beijing, People's Republic of China
| | - Wei Wang
- Wellcome Trust Sanger Institute, Cambridge, United Kingdom
| | - Yanfeng Liang
- Research Center for Animal Genetic Resources of Mongolian Plateau, Inner Mongolia University, Hohhot, People's Republic of China
| | - Lihong Fan
- Research Center for Animal Genetic Resources of Mongolian Plateau, Inner Mongolia University, Hohhot, People's Republic of China
| | - Hongmei Han
- Research Center for Animal Genetic Resources of Mongolian Plateau, Inner Mongolia University, Hohhot, People's Republic of China
| | - Xiaorong Xu
- Research Center for Animal Genetic Resources of Mongolian Plateau, Inner Mongolia University, Hohhot, People's Republic of China
| | - Fuchou Tang
- Biodynamic Optical Imaging Center (BIOPIC), Peking University, Beijing, People's Republic of China.,College of Life Sciences, Peking University, Beijing, People's Republic of China
| | - Siqin Bao
- Research Center for Animal Genetic Resources of Mongolian Plateau, Inner Mongolia University, Hohhot, People's Republic of China
| | - Pentao Liu
- Wellcome Trust Sanger Institute, Cambridge, United Kingdom
| | - Xihe Li
- Research Center for Animal Genetic Resources of Mongolian Plateau, Inner Mongolia University, Hohhot, People's Republic of China.,Inner Mongolia Saikexing Institute of Breeding and Reproductive Biotechnology in Domestic Animal, Hohhot, People's Republic of China
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71
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Wada T, Wallerich S, Becskei A. Synthetic Transcription Factors Switch from Local to Long-Range Control during Cell Differentiation. ACS Synth Biol 2019; 8:223-231. [PMID: 30624895 DOI: 10.1021/acssynbio.8b00369] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Genes, including promoters and enhancers, are regulated by short- and long-range interactions in higher eukaryotes. It is unclear how mammalian gene expression subject to such a combinatorial regulation can be controlled by synthetic transcription factors (TF). Here, we studied how synthetic TALE transcriptional activators and repressors affect the expression of genes in a gene array during cellular differentiation. The protocadherin gene array is silent in mouse embryonic stem (ES) and neuronal progenitor cells. The TALE transcriptional activator recruited to a promoter activates specifically the target gene in ES cells. Upon differentiation into neuronal progenitors, the transcriptional regulatory logic changes: the same activator behaves like an enhancer, activating distant genes in a correlated, stochastic fashion. The long-range effect is reflected by the alterations in CpG methylation. Our findings reveal the limits of precision and the opportunities in the control of gene expression for TF-based therapies in cells of various differentiation stages.
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Affiliation(s)
- Takeo Wada
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
| | - Sandrine Wallerich
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
| | - Attila Becskei
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
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72
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Abstract
The advent of locus-specific protein recruitment technologies has enabled a new class of studies in chromatin biology. Epigenome editors enable biochemical modifications of chromatin at almost any specific endogenous locus. Their locus specificity unlocks unique information including the functional roles of distinct modifications at specific genomic loci. Given the growing interest in using these tools for biological and translational studies, there are many specific design considerations depending on the scientific question or clinical need. Here we present and discuss important design considerations and challenges regarding the biochemical and locus specificities of epigenome editors. These include how to account for the complex biochemical diversity of chromatin; control for potential interdependency of epigenome editors and their resultant modifications; avoid sequestration effects; quantify the locus specificity of epigenome editors; and improve locus specificity by considering concentration, affinity, avidity, and sequestration effects.
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73
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Lebar T, Verbič A, Ljubetič A, Jerala R. Polarized displacement by transcription activator-like effectors for regulatory circuits. Nat Chem Biol 2019; 15:80-87. [PMID: 30455466 DOI: 10.1038/s41589-018-0163-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 10/05/2018] [Indexed: 01/26/2023]
Abstract
The interplay between DNA-binding proteins plays an important role in transcriptional regulation and could increase the precision and complexity of designed regulatory circuits. Here we show that a transcription activator-like effector (TALE) can displace another TALE protein from DNA in a highly polarized manner, displacing only the 3'- but not 5'-bound overlapping or adjacent TALE. We propose that the polarized displacement by TALEs is based on its multipartite nature of binding to DNA. The polarized TALE displacement provides strategies for the specific regulation of gene expression, for construction of all two-input Boolean genetic logic circuits based on the robust propagation of the displacement across multiple neighboring sites, for displacement of zinc finger-based transcription factors and for suppression of Cas9-gRNA-mediated genome cleavage, enriching the synthetic biology toolbox and contributing to the understanding of the underlying principles of the facilitated displacement.
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Affiliation(s)
- Tina Lebar
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Ljubljana, Slovenia
- EN-FIST Centre of Excellence, Ljubljana, Slovenia
| | - Anže Verbič
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Ajasja Ljubetič
- 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.
- EN-FIST Centre of Excellence, Ljubljana, Slovenia.
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74
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Deng P, Carter S, Fink K. Design, Construction, and Application of Transcription Activation-Like Effectors. Methods Mol Biol 2019; 1937:47-58. [PMID: 30706389 DOI: 10.1007/978-1-4939-9065-8_3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Transcription activator-like effectors (TALEs) are modular proteins derived from the plant Xanthomonas sp. pathogen that can be designed to target unique DNA sequences following a simple cipher. Customized TALE proteins can be used in a variety of molecular applications that include gene editing and transcriptional modulation. Presently, we provide a brief primer on the design and construction of TALEs. TALE proteins can be fused to a variety of different effector domains that alter the function of the TALE upon binding. This flexibility of TALE design and downstream effect may offer therapeutic applications that are discussed in this section. Finally, we provide a future perspective on TALE technology and what challenges remain for successful translation of gene-editing strategies to the clinic.
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Affiliation(s)
- Peter Deng
- Stem Cell Program and Institute for Regenerative Cures, University of California, Davis, Sacramento, CA, USA.,Genome Center, MIND Institute, and Biochemistry and Molecular Medicine, University of California, Davis, Davis, CA, USA.,Department of Neurology, University of California Davis , Sacramento, CA, USA
| | - Sakereh Carter
- Stem Cell Program and Institute for Regenerative Cures, University of California, Davis, Sacramento, CA, USA.,Department of Neurology, University of California Davis , Sacramento, CA, USA
| | - Kyle Fink
- Stem Cell Program and Institute for Regenerative Cures, University of California, Davis, Sacramento, CA, USA. .,Department of Neurology, University of California Davis , Sacramento, CA, USA.
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75
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Sanson KR, Hanna RE, Hegde M, Donovan KF, Strand C, Sullender ME, Vaimberg EW, Goodale A, Root DE, Piccioni F, Doench JG. Optimized libraries for CRISPR-Cas9 genetic screens with multiple modalities. Nat Commun 2018; 9:5416. [PMID: 30575746 PMCID: PMC6303322 DOI: 10.1038/s41467-018-07901-8] [Citation(s) in RCA: 476] [Impact Index Per Article: 79.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 12/05/2018] [Indexed: 12/26/2022] Open
Abstract
The creation of genome-wide libraries for CRISPR knockout (CRISPRko), interference (CRISPRi), and activation (CRISPRa) has enabled the systematic interrogation of gene function. Here, we show that our recently-described CRISPRko library (Brunello) is more effective than previously published libraries at distinguishing essential and non-essential genes, providing approximately the same perturbation-level performance improvement over GeCKO libraries as GeCKO provided over RNAi. Additionally, we present genome-wide libraries for CRISPRi (Dolcetto) and CRISPRa (Calabrese), and show in negative selection screens that Dolcetto, with fewer sgRNAs per gene, outperforms existing CRISPRi libraries and achieves comparable performance to CRISPRko in detecting essential genes. We also perform positive selection CRISPRa screens and demonstrate that Calabrese outperforms the SAM approach at identifying vemurafenib resistance genes. We further compare CRISPRa to genome-scale libraries of open reading frames (ORFs). Together, these libraries represent a suite of genome-wide tools to efficiently interrogate gene function with multiple modalities.
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Affiliation(s)
- Kendall R Sanson
- Broad Institute of Harvard and MIT, 75 Ames Street, Cambridge, MA, 02142, USA
| | - Ruth E Hanna
- Broad Institute of Harvard and MIT, 75 Ames Street, Cambridge, MA, 02142, USA
| | - Mudra Hegde
- Broad Institute of Harvard and MIT, 75 Ames Street, Cambridge, MA, 02142, USA
| | - Katherine F Donovan
- Broad Institute of Harvard and MIT, 75 Ames Street, Cambridge, MA, 02142, USA
| | - Christine Strand
- Broad Institute of Harvard and MIT, 75 Ames Street, Cambridge, MA, 02142, USA
| | - Meagan E Sullender
- Broad Institute of Harvard and MIT, 75 Ames Street, Cambridge, MA, 02142, USA
| | - Emma W Vaimberg
- Broad Institute of Harvard and MIT, 75 Ames Street, Cambridge, MA, 02142, USA
| | - Amy Goodale
- Broad Institute of Harvard and MIT, 75 Ames Street, Cambridge, MA, 02142, USA
| | - David E Root
- Broad Institute of Harvard and MIT, 75 Ames Street, Cambridge, MA, 02142, USA
| | - Federica Piccioni
- Broad Institute of Harvard and MIT, 75 Ames Street, Cambridge, MA, 02142, USA
| | - John G Doench
- Broad Institute of Harvard and MIT, 75 Ames Street, Cambridge, MA, 02142, USA.
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76
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Han S, Wei S, Wang X, Han X, Zhang M, Su M, Li Y, Guo J, Zeng W, Liu J, Gao Y, Shen L. Enhanced intrinsic CYP3A4 activity in human hepatic C3A cells with optically controlled CRISPR/dCas9 activator complex. Integr Biol (Camb) 2018; 10:780-790. [PMID: 30520487 DOI: 10.1039/c8ib00109j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Human hepatic C3A cells have been applied in bioartificial liver development, although these cells display low intrinsic cytochrome P450 3A4 (CYP3A4) enzyme activity. We aimed to enhance CYP3A4 enzyme activity of C3A cells utilizing CRISPR gene editing technology. We designed two CYP3A4 expression enhanced systems applying clustered regularly interspaced short palindromic repeats (CRISPR) gene technology: a CRISPR-on activation system including dCas9-VP64-GFP and two U6-sgRNA-mCherry elements, and a light-controlled CRISPR-on activation system combining our CRISPR-on activation system with an optical control system to facilitate regulation of CYP3A4 expression for various applications. Results of enzymatic activity assays displayed increased CYP3A4 activity in C3A cells expressing the CRISPR-on activation system compared with C3A cells. In addition, CYP3A4 activity increased in C3A cells expressing the light-controlled CRISPR-on activation system under blue light radiation compared with C3A cells. Notably, there was no statistical difference in the increase of CYP3A4 protein amounts induced by these two methods. After expansion in culture, C3A cells with the light-controlled CRISPR-on activation system exhibited no statistical difference in CYP3A4 mRNA levels between generations. Our findings provide a method to stably enhance functional gene expression in bioartificial liver cells with the potential for large-scale cell expansion.
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Affiliation(s)
- Shuo Han
- Department of Cell Biology, School of Basic Medical Sciences, Peking University Health Science Center, Haidian District, Beijing, 100191, China.
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77
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Hurtado Del Pozo C, Garreta E, Izpisúa Belmonte JC, Montserrat N. Modeling epigenetic modifications in renal development and disease with organoids and genome editing. Dis Model Mech 2018; 11:dmm035048. [PMID: 30459215 PMCID: PMC6262817 DOI: 10.1242/dmm.035048] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Understanding epigenetic mechanisms is crucial to our comprehension of gene regulation in development and disease. In the past decades, different studies have shown the role of epigenetic modifications and modifiers in renal disease, especially during its progression towards chronic and end-stage renal disease. Thus, the identification of genetic variation associated with chronic kidney disease has resulted in better clinical management of patients. Despite the importance of these findings, the translation of genotype-phenotype data into gene-based medicine in chronic kidney disease populations still lacks faithful cellular or animal models that recapitulate the key aspects of the human kidney. The latest advances in the field of stem cells have shown that it is possible to emulate kidney development and function with organoids derived from human pluripotent stem cells. These have successfully recapitulated not only kidney differentiation, but also the specific phenotypical traits related to kidney function. The combination of this methodology with CRISPR/Cas9 genome editing has already helped researchers to model different genetic kidney disorders. Nowadays, CRISPR/Cas9-based approaches also allow epigenetic modifications, and thus represent an unprecedented tool for the screening of genetic variants, epigenetic modifications or even changes in chromatin structure that are altered in renal disease. In this Review, we discuss these technical advances in kidney modeling, and offer an overview of the role of epigenetic regulation in kidney development and disease.
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Affiliation(s)
- Carmen Hurtado Del Pozo
- Pluripotency for organ regeneration. Institute for Bioengineering of Catalonia (IBEC), the Barcelona Institute of Technology (BIST), 08028 Barcelona, Spain
| | - Elena Garreta
- Pluripotency for organ regeneration. Institute for Bioengineering of Catalonia (IBEC), the Barcelona Institute of Technology (BIST), 08028 Barcelona, Spain
| | | | - Nuria Montserrat
- Pluripotency for organ regeneration. Institute for Bioengineering of Catalonia (IBEC), the Barcelona Institute of Technology (BIST), 08028 Barcelona, Spain
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78
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Ramsuran V, Ewy R, Nguyen H, Kulkarni S. Variation in the Untranslated Genome and Susceptibility to Infections. Front Immunol 2018; 9:2046. [PMID: 30245696 PMCID: PMC6137953 DOI: 10.3389/fimmu.2018.02046] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 08/20/2018] [Indexed: 12/11/2022] Open
Abstract
The clinical outcomes of infections are highly variable among individuals and are determined by complex host-pathogen interactions. Genome-wide association studies (GWAS) are powerful tools to unravel common genetic variations that are associated with disease risk and clinical outcomes. However, GWAS has only rarely revealed information on the exact genetic elements and their effects underlying an association because the majority of the hits are within non-coding regions. Some of the variants or the linked polymorphisms are now being discovered to have functional significance, such as regulatory elements in the promoter and enhancer regions or the microRNA binding sites in the 3′untranslated region of the protein-coding genes, which influence transcription, RNA stability, and translation of the protein-coding genes. However, only 3% of the entire transcriptome is protein-coding, signifying that non-coding RNAs represent most of the transcripts. Thus, a large portion of previously identified intergenic GWAS single nucleotide polymorphisms (SNPs) is in the non-coding RNAs. The non-coding RNAs form a large-scale regulatory network across the transcriptome, greatly expanding the complexity of gene regulation. Accumulating evidence also suggests that the “non-coding” genome regions actively regulate the highly dynamic three dimensional (3D) chromatin structures, which are critical for genome function. Epigenetic modulation like DNA methylation and histone modifications further affect chromatin accessibility and gene expression adding another layer of complexity to the functional interpretation of genetic variation associated with disease outcomes. We provide an overview of the current information on the influence of variation in these “untranslated” regions of the human genome on infectious diseases. The focus of this review is infectious disease-associated polymorphisms and gene regulatory mechanisms of pathophysiological relevance.
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Affiliation(s)
- Veron Ramsuran
- Centre for the AIDS Programme of Research in South Africa, KwaZulu-Natal Research Innovation and Sequencing Platform, School of Laboratory Medicine and Medical Sciences, Nelson R. Mandela School of Medicine, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Rodger Ewy
- Genetics Department, Texas Biomedical Research Institute, San Antonio, TX, United States
| | - Hoang Nguyen
- Genetics Department, Texas Biomedical Research Institute, San Antonio, TX, United States
| | - Smita Kulkarni
- Genetics Department, Texas Biomedical Research Institute, San Antonio, TX, United States
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79
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Weltner J, Balboa D, Katayama S, Bespalov M, Krjutškov K, Jouhilahti EM, Trokovic R, Kere J, Otonkoski T. Human pluripotent reprogramming with CRISPR activators. Nat Commun 2018; 9:2643. [PMID: 29980666 PMCID: PMC6035213 DOI: 10.1038/s41467-018-05067-x] [Citation(s) in RCA: 104] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 06/13/2018] [Indexed: 02/08/2023] Open
Abstract
CRISPR-Cas9-based gene activation (CRISPRa) is an attractive tool for cellular reprogramming applications due to its high multiplexing capacity and direct targeting of endogenous loci. Here we present the reprogramming of primary human skin fibroblasts into induced pluripotent stem cells (iPSCs) using CRISPRa, targeting endogenous OCT4, SOX2, KLF4, MYC, and LIN28A promoters. The low basal reprogramming efficiency can be improved by an order of magnitude by additionally targeting a conserved Alu-motif enriched near genes involved in embryo genome activation (EEA-motif). This effect is mediated in part by more efficient activation of NANOG and REX1. These data demonstrate that human somatic cells can be reprogrammed into iPSCs using only CRISPRa. Furthermore, the results unravel the involvement of EEA-motif-associated mechanisms in cellular reprogramming.
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Affiliation(s)
- Jere Weltner
- Research Programs Unit, Molecular Neurology and Biomedicum Stem Cell Centre, Faculty of Medicine, University of Helsinki, Helsinki, 00014, Finland.
| | - Diego Balboa
- Research Programs Unit, Molecular Neurology and Biomedicum Stem Cell Centre, Faculty of Medicine, University of Helsinki, Helsinki, 00014, Finland
| | - Shintaro Katayama
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, 141 83, Sweden
| | - Maxim Bespalov
- Research Programs Unit, Molecular Neurology and Biomedicum Stem Cell Centre, Faculty of Medicine, University of Helsinki, Helsinki, 00014, Finland
| | - Kaarel Krjutškov
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, 141 83, Sweden
- Competence Centre on Health Technologies, Tartu, 50410, Estonia
| | - Eeva-Mari Jouhilahti
- Research Programs Unit, Molecular Neurology and Biomedicum Stem Cell Centre, Faculty of Medicine, University of Helsinki, Helsinki, 00014, Finland
| | - Ras Trokovic
- Research Programs Unit, Molecular Neurology and Biomedicum Stem Cell Centre, Faculty of Medicine, University of Helsinki, Helsinki, 00014, Finland
| | - Juha Kere
- Research Programs Unit, Molecular Neurology and Biomedicum Stem Cell Centre, Faculty of Medicine, University of Helsinki, Helsinki, 00014, Finland.
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, 141 83, Sweden.
- School of Basic and Medical Biosciences, Guy's Hospital, King's College London, London, SE1 9RT, UK.
- Folkhälsan Institute of Genetics, Helsinki, 00290, Finland.
| | - Timo Otonkoski
- Research Programs Unit, Molecular Neurology and Biomedicum Stem Cell Centre, Faculty of Medicine, University of Helsinki, Helsinki, 00014, Finland.
- Children's Hospital, Helsinki University Central Hospital, University of Helsinki, Helsinki, 00290, Finland.
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80
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Vo BT, Kwon JA, Li C, Finkelstein D, Xu B, Orr BA, Sherr CJ, Roussel MF. Mouse medulloblastoma driven by CRISPR activation of cellular Myc. Sci Rep 2018; 8:8733. [PMID: 29880921 PMCID: PMC5992137 DOI: 10.1038/s41598-018-24956-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 04/11/2018] [Indexed: 12/11/2022] Open
Abstract
MYC-driven Group 3 (G3) medulloblastoma (MB) is the most aggressive of four molecular subgroups classified by transcriptome, genomic landscape and clinical outcomes. Mouse models that recapitulate human G3 MB all rely on retroviral vector-induced Myc expression driven by viral regulatory elements (Retro-Myc tumors). We used nuclease-deficient CRISPR/dCas9-based gene activation with combinatorial single guide RNAs (sgRNAs) to enforce transcription of endogenous Myc in Trp53-null neurospheres that were orthotopically transplanted into the brains of naïve animals. Three combined sgRNAs linked to dCas9-VP160 induced cellular Myc expression and large cell anaplastic MBs (CRISPR-Myc tumors) which recapitulated the molecular characteristics of mouse and human G3 MBs. The BET inhibitor JQ1 suppressed MYC expression in a human G3 MB cell line (HD-MB03) and CRISPR-Myc, but not in Retro-Myc MBs. This G3 MB mouse model in which Myc expression is regulated by its own promoter will facilitate pre-clinical studies with drugs that regulate Myc transcription.
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Affiliation(s)
- BaoHan T Vo
- Department of Tumor Cell Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Jin Ah Kwon
- Department of Tumor Cell Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA.,Howard Hughes Medical Institute, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Chunliang Li
- Department of Tumor Cell Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - David Finkelstein
- Department of Computational Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Beisi Xu
- Department of Computational Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Brent A Orr
- Department of Pathology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Charles J Sherr
- Department of Tumor Cell Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA.,Howard Hughes Medical Institute, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Martine F Roussel
- Department of Tumor Cell Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA.
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81
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Black JB, Gersbach CA. Synthetic transcription factors for cell fate reprogramming. Curr Opin Genet Dev 2018; 52:13-21. [PMID: 29803990 DOI: 10.1016/j.gde.2018.05.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 04/30/2018] [Accepted: 05/06/2018] [Indexed: 12/22/2022]
Abstract
The ability to reprogram cell lineage specification through the activity of master regulatory transcription factors has transformed disease modeling, drug screening, and cell therapy for regenerative medicine. Recent advances in the engineering of synthetic transcription factors to modulate endogenous gene expression networks and chromatin states have generated a new set of tools with unique advantages to study and enhance cell reprogramming methods. Several studies have applied synthetic transcription factors in various cell reprogramming paradigms in human and murine cells. Moreover, the adaption of CRISPR-based transcription factors for high-throughput screening will enable the systematic identification of optimal factors and gene network perturbations to improve current reprogramming protocols and enable conversion to more diverse, highly specified, and mature cell types. The rapid development of next-generation technologies with more robust and versatile functionality will continue to expand the application of synthetic transcription factors for cell reprogramming.
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Affiliation(s)
- Joshua B Black
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA; Center for Genomic and Computational Biology, Duke University, Durham, NC 27708, USA
| | - Charles A Gersbach
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA; Center for Genomic and Computational Biology, Duke University, Durham, NC 27708, USA; Department of Orthopaedic Surgery, Duke University Medical Center, Durham, NC 27710, USA.
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82
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Thakore PI, Kwon JB, Nelson CE, Rouse DC, Gemberling MP, Oliver ML, Gersbach CA. RNA-guided transcriptional silencing in vivo with S. aureus CRISPR-Cas9 repressors. Nat Commun 2018; 9:1674. [PMID: 29700298 PMCID: PMC5920046 DOI: 10.1038/s41467-018-04048-4] [Citation(s) in RCA: 119] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 03/26/2018] [Indexed: 01/01/2023] Open
Abstract
CRISPR-Cas9 transcriptional repressors have emerged as robust tools for disrupting gene regulation in vitro but have not yet been adapted for systemic delivery in adult animal models. Here we describe a Staphylococcus aureus Cas9-based repressor (dSaCas9KRAB) compatible with adeno-associated viral (AAV) delivery. To evaluate dSaCas9KRAB efficacy for gene silencing in vivo, we silenced transcription of Pcsk9, a regulator of cholesterol levels, in the liver of adult mice. Systemic administration of a dual-vector AAV8 system expressing dSaCas9KRAB and a Pcsk9-targeting guide RNA (gRNA) results in significant reductions of serum Pcsk9 and cholesterol levels. Despite a moderate host response to dSaCas9KRAB expression, Pcsk9 repression is maintained for 24 weeks after a single treatment, demonstrating the potential for long-term gene silencing in post-mitotic tissues with dSaCas9KRAB. In vivo programmable gene silencing enables studies that link gene regulation to complex phenotypes and expands the CRISPR-Cas9 perturbation toolbox for basic research and gene therapy applications.
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Affiliation(s)
- Pratiksha I Thakore
- Department of Biomedical Engineering, Duke University, Durham, 27708, NC, USA
- Center for Genomic and Computational Biology, Duke University, Durham, 27708, NC, USA
| | - Jennifer B Kwon
- Center for Genomic and Computational Biology, Duke University, Durham, 27708, NC, USA
- University Program in Genetics and Genomics, Duke University Medical Center, Durham, 27710, NC, USA
| | - Christopher E Nelson
- Department of Biomedical Engineering, Duke University, Durham, 27708, NC, USA
- Center for Genomic and Computational Biology, Duke University, Durham, 27708, NC, USA
| | - Douglas C Rouse
- Division of Laboratory Animal Resources, Duke University School of Medicine, Durham, 27710, NC, USA
| | - Matthew P Gemberling
- Department of Biomedical Engineering, Duke University, Durham, 27708, NC, USA
- Center for Genomic and Computational Biology, Duke University, Durham, 27708, NC, USA
| | - Matthew L Oliver
- Department of Biomedical Engineering, Duke University, Durham, 27708, NC, USA
| | - Charles A Gersbach
- Department of Biomedical Engineering, Duke University, Durham, 27708, NC, USA.
- Center for Genomic and Computational Biology, Duke University, Durham, 27708, NC, USA.
- Department of Orthopaedic Surgery, Duke University Medical Center, Durham, 27710, NC, USA.
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83
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Zhang C, Quan R, Wang J. Development and application of CRISPR/Cas9 technologies in genomic editing. Hum Mol Genet 2018; 27:R79-R88. [DOI: 10.1093/hmg/ddy120] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 04/03/2018] [Indexed: 12/13/2022] Open
Affiliation(s)
- Cui Zhang
- Institute of Cell and Development Biology, College of Life Sciences, Zijingang Campus, Zhejiang University, Hangzhou, Zhejiang, P.R. China
| | - Renfu Quan
- Institute of Orthopedics, Xiaoshan Traditional Chinese Medical Hospital, Hangzhou, Zhejiang, China
| | - Jinfu Wang
- Institute of Cell and Development Biology, College of Life Sciences, Zijingang Campus, Zhejiang University, Hangzhou, Zhejiang, P.R. China
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84
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Zhao C, Zhang Y, Zhao Y, Ying Y, Ai R, Zhang J, Wang Y. Multiple Chemical Inducible Tal Effectors for Genome Editing and Transcription Activation. ACS Chem Biol 2018; 13:609-617. [PMID: 29308880 DOI: 10.1021/acschembio.7b00606] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Inducible modulation is often required for precise investigations and manipulations of dynamic biological processes. Transcription activator-like effectors (TALEs) provide a powerful tool for targeted gene editing and transcriptional programming. We designed a series of chemical inducible systems by coupling TALEs with a mutated human estrogen receptor (ERT2), which renders them 4-hydroxyl-tamoxifen (4-OHT) inducible for access of the genome. Chemical inducible genome editing was achieved via fusing two tandem ERT2 domains to customized transcription activator-like effector nuclease (TALEN), which we termed "Hybrid Inducible Technology" (HIT-TALEN). Those for transcription activation were vigorously optimized using multiple construct designs. Most efficient drug induction for endogenous gene activation was accomplished with minimal background activity using an optimized inducible TALE based SunTag system (HIT-TALE-SunTag). The HIT-SunTag system is rapid, tunable, selective to 4-OHT over an endogenous ligand, and reversible in drug induced transcriptional activation. Versatile systems developed in this study can be easily applied for editing and transcriptional programming of potentially any genomic loci in a tight and effective chemical inducible fashion.
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Affiliation(s)
- Chen Zhao
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101 China
| | - Yue Zhang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101 China
| | - Yingze Zhao
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101 China
| | - Yue Ying
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101 China
| | - Runna Ai
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101 China
| | - Jingfang Zhang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101 China
| | - Yu Wang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
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85
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Xiong K, Zhou Y, Blichfeld KA, Hyttel P, Bolund L, Freude KK, Luo Y. RNA-Guided Activation of Pluripotency Genes in Human Fibroblasts. Cell Reprogram 2018; 19:189-198. [PMID: 28557624 DOI: 10.1089/cell.2017.0006] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Specific activation of endogenous genes can be achieved by programmable artificial transcription factors (ATFs). In this study, we compared two artificial, programmable, clustered regularly interspaced short palindromic repeats (CRISPR)-based, ubiquitous transcription factors: deficient CRISPR-associated protein 9 (dCas9)-VP64 (CRISPRa) alone, or a combination of dCas9-VP64 and MS2-P65-HSF1 [synergistic activation mediator (SAM) system] mediated activation of five pluripotency genes: KLF4 (K), LIN28 (L), MYC (M), OCT4 (O), and SOX2 (S) in human cells (HEK293T, HeLa, HepG2, and primary fibroblasts). Activation potential was monitored using a luciferase reporter system and we found that both CRISPRa and SAM can efficiently activate the proximal promoter of all five genes. We also observed that the guide RNA (gRNA) target sites and number of gRNAs have a major effect on gRNA-guided activation efficiency. Furthermore, increased activation efficiency (>3-folds) could be achieved by the SAM system compared to CRISPRa. In addition, we discovered that only the SAM system could efficiently activate LIN28, OCT4, and SOX2 expression (up to 100-folds compared to coexpression with a scrambled gRNA) in primary human fibroblasts. This SAM-mediated activation of LOS can be stably maintained for over 20 days in fibroblasts cultured in either fibroblasts or stem cell medium. However, when attempting to use the SAM-LOS activation as an approach for induced pluripotent stem cells-reprogramming, no embryonic stem-like colonies could be obtained from these SAM fibroblasts. In conclusion, our study showed that CRISPR/Cas9-based ATFs are potent to activate and maintain transcription of endogenous human pluripotent genes. However, future improvements of the system are still required to improve activation efficiency and cellular reprogramming using ATFs.
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Affiliation(s)
- Kai Xiong
- 1 Department of Veterinary Clinical and Animal Sciences, University of Copenhagen , Frederiksberg, Denmark
| | - Yan Zhou
- 2 Danish Regenerative Engineering Alliance for Medicine, Department of Biomedicine, Aarhus University , Aarhus, Denmark
| | - Kristian Aabo Blichfeld
- 2 Danish Regenerative Engineering Alliance for Medicine, Department of Biomedicine, Aarhus University , Aarhus, Denmark
| | - Poul Hyttel
- 1 Department of Veterinary Clinical and Animal Sciences, University of Copenhagen , Frederiksberg, Denmark
| | - Lars Bolund
- 2 Danish Regenerative Engineering Alliance for Medicine, Department of Biomedicine, Aarhus University , Aarhus, Denmark
| | - Kristine Karla Freude
- 1 Department of Veterinary Clinical and Animal Sciences, University of Copenhagen , Frederiksberg, Denmark
| | - Yonglun Luo
- 2 Danish Regenerative Engineering Alliance for Medicine, Department of Biomedicine, Aarhus University , Aarhus, Denmark
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86
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Klein JC, Chen W, Gasperini M, Shendure J. Identifying Novel Enhancer Elements with CRISPR-Based Screens. ACS Chem Biol 2018; 13:326-332. [PMID: 29300083 PMCID: PMC6218247 DOI: 10.1021/acschembio.7b00778] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Enhancers control the spatiotemporal expression of genes and are essential for encoding differentiation and development. Since their discovery more than three decades ago, researchers have largely studied enhancers removed from their genomic context. The recent adaptation of CRISPR/Cas9 to genome editing in higher organisms now allows researchers to perturb and test these elements in their genomic context, through both mutation and epigenetic modulation. In this Perspective, we discuss recent advances in scanning noncoding regions of the genome for enhancer activity using CRISPR-based tools.
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Affiliation(s)
- Jason C. Klein
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, United States
| | - Wei Chen
- Molecular Engineering & Science Institute, University of Washington, Seattle, Washington 98195, United States
| | - Molly Gasperini
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, United States
| | - Jay Shendure
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, United States
- Howard Hughes Medical Institute, University of Washington, Seattle, Washington 98195, United States
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87
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Kiełbus M, Czapiński J, Odrzywolski A, Stasiak G, Szymańska K, Kałafut J, Kos M, Giannopoulos K, Stepulak A, Rivero-Müller A. Optogenetics in cancer drug discovery. Expert Opin Drug Discov 2018; 13:459-472. [DOI: 10.1080/17460441.2018.1437138] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Michał Kiełbus
- Department of Biochemistry and Molecular Biology, Medical University of Lublin, Lublin, Poland
| | - Jakub Czapiński
- Department of Biochemistry and Molecular Biology, Medical University of Lublin, Lublin, Poland
- Postgraduate School of Molecular Medicine, Medical University of Warsaw, Warsaw, Poland
| | - Adrian Odrzywolski
- Department of Biochemistry and Molecular Biology, Medical University of Lublin, Lublin, Poland
| | - Grażyna Stasiak
- Department of Experimental Haematooncology, Medical University of Lublin, Lublin, Poland
| | - Kamila Szymańska
- Department of Biochemistry and Molecular Biology, Medical University of Lublin, Lublin, Poland
| | - Joanna Kałafut
- Department of Biochemistry and Molecular Biology, Medical University of Lublin, Lublin, Poland
| | - Michał Kos
- Department of Biochemistry and Molecular Biology, Medical University of Lublin, Lublin, Poland
| | - Krzysztof Giannopoulos
- Department of Experimental Haematooncology, Medical University of Lublin, Lublin, Poland
- Department of Hematology, St. John’s Cancer Center, Lublin, Poland
| | - Andrzej Stepulak
- Department of Biochemistry and Molecular Biology, Medical University of Lublin, Lublin, Poland
| | - Adolfo Rivero-Müller
- Department of Biochemistry and Molecular Biology, Medical University of Lublin, Lublin, Poland
- Cell Biology, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland
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88
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Waking up dormant tumor suppressor genes with zinc fingers, TALEs and the CRISPR/dCas9 system. Oncotarget 2018; 7:60535-60554. [PMID: 27528034 PMCID: PMC5312401 DOI: 10.18632/oncotarget.11142] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 07/19/2016] [Indexed: 12/24/2022] Open
Abstract
The aberrant epigenetic silencing of tumor suppressor genes (TSGs) plays a major role during carcinogenesis and regaining these dormant functions by engineering of sequence-specific epigenome editing tools offers a unique opportunity for targeted therapies. However, effectively normalizing the expression and regaining tumor suppressive functions of silenced TSGs by artificial transcription factors (ATFs) still remains a major challenge. Herein we describe novel combinatorial strategies for the potent reactivation of two class II TSGs, MASPIN and REPRIMO, in cell lines with varying epigenetic states, using the CRISPR/dCas9 associated system linked to a panel of effector domains (VP64, p300, VPR and SAM complex), as well as with protein-based ATFs, Zinc Fingers and TALEs. We found that co-delivery of multiple effector domains using a combination of CRISPR/dCas9 and TALEs or SAM complex maximized activation in highly methylated promoters. In particular, CRISPR/dCas9 VPR with SAM upregulated MASPIN mRNA (22,145-fold change) in H157 lung cancer cells, with accompanying re-expression of MASPIN protein, which led to a concomitant inhibition of cell proliferation and induction of apoptotic cell death. Consistently, CRISPR/dCas9 VP64 with SAM upregulated REPRIMO (680-fold change), which led to phenotypic reprogramming in AGS gastric cancer cells. Altogether, our results outlined novel sequence-specific, combinatorial epigenome editing approaches to reactivate highly methylated TSGs as a promising therapy for cancer and other diseases.
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89
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Gogolok S, Köber U, Pollard SM. STAR: A Simple TAL Effector Assembly Reaction Using Isothermal Assembly. Methods Mol Biol 2018; 1772:477-490. [PMID: 29754248 DOI: 10.1007/978-1-4939-7795-6_29] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Transcription activator-like effectors (TALEs) contain programmable DNA-binding domains that can be fused to various effectors to manipulate genetic sequences or transcriptional state. However, the construction of plasmids encoding the modular DNA-binding domain remains challenging due to their repetitive nature. Here, we describe methods for a simple TALE assembly reaction (STAR) that uses a 68-part plasmid library to create TALEs binding to 17 bp target sequences. Manual production of many tens of TALEs can be achieved using a simple 8 h protocol, with full length sequence-verified plasmids available within a few days. This simple tale assembly reaction (STAR) provides a convenient method for generating tens to hundreds of TALENs or TALE-TFs without the need for large plasmid libraries or expensive liquid handling.
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Affiliation(s)
- Sabine Gogolok
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, UK
| | - Ute Köber
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, UK
| | - Steven M Pollard
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, UK.
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90
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Waryah CB, Moses C, Arooj M, Blancafort P. Zinc Fingers, TALEs, and CRISPR Systems: A Comparison of Tools for Epigenome Editing. Methods Mol Biol 2018. [PMID: 29524128 DOI: 10.1007/978-1-4939-7774-1_2] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The completion of genome, epigenome, and transcriptome mapping in multiple cell types has created a demand for precision biomolecular tools that allow researchers to functionally manipulate DNA, reconfigure chromatin structure, and ultimately reshape gene expression patterns. Epigenetic editing tools provide the ability to interrogate the relationship between epigenetic modifications and gene expression. Importantly, this information can be exploited to reprogram cell fate for both basic research and therapeutic applications. Three different molecular platforms for epigenetic editing have been developed: zinc finger proteins (ZFs), transcription activator-like effectors (TALEs), and the system of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and CRISPR-associated (Cas) proteins. These platforms serve as custom DNA-binding domains (DBDs), which are fused to epigenetic modifying domains to manipulate epigenetic marks at specific sites in the genome. The addition and/or removal of epigenetic modifications reconfigures local chromatin structure, with the potential to provoke long-lasting changes in gene transcription. Here we summarize the molecular structure and mechanism of action of ZF, TALE, and CRISPR platforms and describe their applications for the locus-specific manipulation of the epigenome. The advantages and disadvantages of each platform will be discussed with regard to genomic specificity, potency in regulating gene expression, and reprogramming cell phenotypes, as well as ease of design, construction, and delivery. Finally, we outline potential applications for these tools in molecular biology and biomedicine and identify possible barriers to their future clinical implementation.
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Affiliation(s)
- Charlene Babra Waryah
- Cancer Epigenetics Group, The Harry Perkins Institute of Medical Research, Nedlands, Perth, WA, Australia
| | - Colette Moses
- Cancer Epigenetics Group, The Harry Perkins Institute of Medical Research, Nedlands, Perth, WA, Australia
- School of Human Sciences, The University of Western Australia, Perth, WA, Australia
| | - Mahira Arooj
- Cancer Epigenetics Group, The Harry Perkins Institute of Medical Research, Nedlands, Perth, WA, Australia
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, WA, Australia
| | - Pilar Blancafort
- Cancer Epigenetics Group, The Harry Perkins Institute of Medical Research, Nedlands, Perth, WA, Australia.
- School of Human Sciences, The University of Western Australia, Perth, WA, Australia.
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91
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Abstract
Studies of the mammalian nervous system have revealed widespread epigenetic regulation underlying gene expression intrinsic to basic neurobiological function as well as neurological disease. Over the past decade, a critical role has emerged for the neural regulation of chromatin-modifying enzymes during both development and adulthood, and in response to external stimuli. These biochemical data are complemented by numerous next generation sequencing (NGS) studies that quantify the extent of chromatin and DNA modifications in neurons. Neuroepigenetic editing tools can be applied to distinguish between the mere presence and functional relevance of such modifications to neural transcription and animal behavior. This review discusses current advances in neuroepigenetic editing, highlighting methodological considerations pertinent to neuroscience, such as delivery methods and the spatiotemporal specificity of editing. Although neuroepigenetic editing is a nascent field, the studies presented in this review demonstrate the enormous potential of this approach for basic neurobiological research and therapeutic application.
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Affiliation(s)
- Peter J Hamilton
- The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, NY, New York, USA
| | - Carissa J Lim
- Department of Pharmacology, The University of Pennsylvania, Philadelphia, PA, USA
| | - Eric J Nestler
- The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, NY, New York, USA
| | - Elizabeth A Heller
- Department of Pharmacology, The University of Pennsylvania, Philadelphia, PA, USA. .,Penn Epigenetics Institute, The University of Pennsylvania, Philadelphia, PA, USA.
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92
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Martinez-Lage M, Torres-Ruiz R, Rodriguez-Perales S. CRISPR/Cas9 Technology: Applications and Human Disease Modeling. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2017; 152:23-48. [PMID: 29150003 DOI: 10.1016/bs.pmbts.2017.09.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The CRISPR/Cas9 system development has revolutionized the field of genome engineering through the efficient creation of targeted breaks in the DNA of almost any organism and cell type, opening an avenue for a wide range of applications in biomedical research and medicine. Apart from gene edition through knock-in or knock-out approaches, CRISPR/Cas9 technology has been used for many other purposes, including regulation of endogenous gene expression, epigenome editing, live-cell imaging of chromosomal loci, edition of RNA and high-throughput screening. With all those technological improvements, CRISPR/Cas9 system has broadened the number of alternatives for studying gene function and the generation of more accurate disease models. Although many mechanistic questions remain to be answered and several challenges have yet to be addressed, the use of CRISPR/Cas9-based genome engineering technologies will increase our knowledge of disease processes and their treatment in the near future.
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Affiliation(s)
- Marta Martinez-Lage
- Molecular Cytogenetics and Genome Engineering Group, Centro Nacional Investigaciones Oncológicas (CNIO), Madrid, Spain
| | - Raúl Torres-Ruiz
- Molecular Cytogenetics and Genome Engineering Group, Centro Nacional Investigaciones Oncológicas (CNIO), Madrid, Spain.
| | - Sandra Rodriguez-Perales
- Molecular Cytogenetics and Genome Engineering Group, Centro Nacional Investigaciones Oncológicas (CNIO), Madrid, Spain.
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93
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Machens F, Balazadeh S, Mueller-Roeber B, Messerschmidt K. Synthetic Promoters and Transcription Factors for Heterologous Protein Expression in Saccharomyces cerevisiae. Front Bioeng Biotechnol 2017; 5:63. [PMID: 29098147 PMCID: PMC5653697 DOI: 10.3389/fbioe.2017.00063] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 09/29/2017] [Indexed: 12/19/2022] Open
Abstract
Orthogonal systems for heterologous protein expression as well as for the engineering of synthetic gene regulatory circuits in hosts like Saccharomyces cerevisiae depend on synthetic transcription factors (synTFs) and corresponding cis-regulatory binding sites. We have constructed and characterized a set of synTFs based on either transcription activator-like effectors or CRISPR/Cas9, and corresponding small synthetic promoters (synPs) with minimal sequence identity to the host’s endogenous promoters. The resulting collection of functional synTF/synP pairs confers very low background expression under uninduced conditions, while expression output upon induction of the various synTFs covers a wide range and reaches induction factors of up to 400. The broad spectrum of expression strengths that is achieved will be useful for various experimental setups, e.g., the transcriptional balancing of expression levels within heterologous pathways or the construction of artificial regulatory networks. Furthermore, our analyses reveal simple rules that enable the tuning of synTF expression output, thereby allowing easy modification of a given synTF/synP pair. This will make it easier for researchers to construct tailored transcriptional control systems.
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Affiliation(s)
- Fabian Machens
- University of Potsdam, Cell2Fab Research Unit, Potsdam, Germany
| | - Salma Balazadeh
- Max-Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany.,Department Molecular Biology, University of Potsdam, Potsdam, Germany
| | - Bernd Mueller-Roeber
- Max-Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany.,Department Molecular Biology, University of Potsdam, Potsdam, Germany
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94
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Abstract
Controlling the exchange of genetic information between sexually reproducing populations has applications in agriculture, eradication of disease vectors, control of invasive species, and the safe study of emerging biotechnology applications. Here we introduce an approach to engineer a genetic barrier to sexual reproduction between otherwise compatible populations. Programmable transcription factors drive lethal gene expression in hybrid offspring following undesired mating events. As a proof of concept, we target the ACT1 promoter of the model organism Saccharomyces cerevisiae using a dCas9-based transcriptional activator. Lethal overexpression of actin results from mating this engineered strain with a strain containing the wild-type ACT1 promoter. Genetic isolation of a genetically modified organism represents a useful strategy for biocontainment. Here the authors use dCas9-VP64-driven gene expression to construct a ‘species-like’ barrier to reproduction between two otherwise compatible populations.
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95
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Beyond Native Cas9: Manipulating Genomic Information and Function. Trends Biotechnol 2017; 35:983-996. [DOI: 10.1016/j.tibtech.2017.06.004] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 05/22/2017] [Accepted: 06/08/2017] [Indexed: 02/07/2023]
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96
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Naseri G, Balazadeh S, Machens F, Kamranfar I, Messerschmidt K, Mueller-Roeber B. Plant-Derived Transcription Factors for Orthologous Regulation of Gene Expression in the Yeast Saccharomyces cerevisiae. ACS Synth Biol 2017; 6:1742-1756. [PMID: 28531348 DOI: 10.1021/acssynbio.7b00094] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Control of gene expression by transcription factors (TFs) is central in many synthetic biology projects for which a tailored expression of one or multiple genes is often needed. As TFs from evolutionary distant organisms are unlikely to affect gene expression in a host of choice, they represent excellent candidates for establishing orthogonal control systems. To establish orthogonal regulators for use in yeast (Saccharomyces cerevisiae), we chose TFs from the plant Arabidopsis thaliana. We established a library of 106 different combinations of chromosomally integrated TFs, activation domains (yeast GAL4 AD, herpes simplex virus VP64, and plant EDLL) and synthetic promoters harboring cognate cis-regulatory motifs driving a yEGFP reporter. Transcriptional output of the different driver/reporter combinations varied over a wide spectrum, with EDLL being a considerably stronger transcription activation domain in yeast than the GAL4 activation domain, in particular when fused to Arabidopsis NAC TFs. Notably, the strength of several NAC-EDLL fusions exceeded that of the strong yeast TDH3 promoter by 6- to 10-fold. We furthermore show that plant TFs can be used to build regulatory systems encoded by centromeric or episomal plasmids. Our library of TF-DNA binding site combinations offers an excellent tool for diverse synthetic biology applications in yeast.
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Affiliation(s)
| | - Salma Balazadeh
- Plant
Signalling Group, Max-Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, Potsdam, 14476, Germany
| | | | | | | | - Bernd Mueller-Roeber
- Plant
Signalling Group, Max-Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, Potsdam, 14476, Germany
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97
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Elkon R, Agami R. Characterization of noncoding regulatory DNA in the human genome. Nat Biotechnol 2017; 35:732-746. [DOI: 10.1038/nbt.3863] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 03/31/2017] [Indexed: 12/22/2022]
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98
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Rathnam C, Chueng STD, Yang L, Lee KB. Advanced Gene Manipulation Methods for Stem Cell Theranostics. Theranostics 2017; 7:2775-2793. [PMID: 28824715 PMCID: PMC5562215 DOI: 10.7150/thno.19443] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 04/18/2017] [Indexed: 12/20/2022] Open
Abstract
In the field of tissue engineering, autologous cell sources are ideal to prevent adverse immune responses; however, stable and reliable cell sources are limited. To acquire more reliable cell sources, the harvesting and differentiation of stem cells from patients is becoming more and more common. To this end, the need to control the fate of these stem cells before transplantation for therapeutic purposes is urgent. Since transcription factors orchestrate all of the gene activities inside of a cell, researchers have developed engineered and synthetic transcription factors to precisely control the fate of stem cells allowing for safer and more effective cell sources. Engineered transcription factors, mutant fusion proteins of naturally occurring proteins, comprise the three main domains of natural transcription factors including DNA binding domains, transcriptional activation domains, and a linker domain. Several key advancements of engineered zinc finger proteins, transcriptional activator-like effectors, and deficient cas9 proteins have revolutionized the field of engineered transcription factors allowing for precise control of gene regulation. Synthetic transcription factors are chemically made transcription factor mimics that use small molecule based moieties to replicate the main functions of natural transcription factors. These include hairpin polyamides, triple helix forming oligonucleotides, and nanoparticle-based methods. Synthetic transcription factors allow for non-viral delivery and greater spatiotemporal control of gene expression. The developments in engineered and synthetic transcription factors have lowered the risk of tumorigenicity and improved differentiation capability of stem cells, as well as facilitated many key discoveries in the fields of cancer and stem cell biology, thus providing a stepping stone to advance regenerative medicine in the clinic for cell replacement therapies.
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99
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Abstract
The discovery and adaption of bacterial clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated (Cas) systems has revolutionized the way researchers edit genomes. Engineering of catalytically inactivated Cas variants (nuclease-deficient or nuclease-deactivated [dCas]) combined with transcriptional repressors, activators, or epigenetic modifiers enable sequence-specific regulation of gene expression and chromatin state. These CRISPR-Cas-based technologies have contributed to the rapid development of disease models and functional genomics screening approaches, which can facilitate genetic target identification and drug discovery. In this short review, we will cover recent advances of CRISPR-dCas9 systems and their use for transcriptional repression and activation, epigenome editing, and engineered synthetic circuits for complex control of the mammalian genome.
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Affiliation(s)
- Albert Lo
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Lei Qi
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
- Department of Chemical and Systems Biology, Stanford University, Stanford, CA 94305, USA
- ChEM-H, Stanford University, Stanford, CA 94305, USA
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100
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Canver MC, Bauer DE, Orkin SH. Functional interrogation of non-coding DNA through CRISPR genome editing. Methods 2017; 121-122:118-129. [PMID: 28288828 PMCID: PMC5483188 DOI: 10.1016/j.ymeth.2017.03.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 02/18/2017] [Accepted: 03/03/2017] [Indexed: 12/26/2022] Open
Abstract
Methodologies to interrogate non-coding regions have lagged behind coding regions despite comprising the vast majority of the genome. However, the rapid evolution of clustered regularly interspaced short palindromic repeats (CRISPR)-based genome editing has provided a multitude of novel techniques for laboratory investigation including significant contributions to the toolbox for studying non-coding DNA. CRISPR-mediated loss-of-function strategies rely on direct disruption of the underlying sequence or repression of transcription without modifying the targeted DNA sequence. CRISPR-mediated gain-of-function approaches similarly benefit from methods to alter the targeted sequence through integration of customized sequence into the genome as well as methods to activate transcription. Here we review CRISPR-based loss- and gain-of-function techniques for the interrogation of non-coding DNA.
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Affiliation(s)
| | - Daniel E Bauer
- Harvard Medical School, Boston, MA 02115, United States; Division of Hematology/Oncology, Boston Children's Hospital, Boston, MA 02115, United States; Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA 02115, United States.
| | - Stuart H Orkin
- Harvard Medical School, Boston, MA 02115, United States; Division of Hematology/Oncology, Boston Children's Hospital, Boston, MA 02115, United States; Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA 02115, United States; Howard Hughes Medical Institute, Boston, MA 02115, United States.
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