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Gillespie W, Zhang Y, Ruiz OE, Cerda J, Ortiz-Guzman J, Turner WD, Largoza G, Sherman M, Mosser LE, Fujimoto E, Chien CB, Kwan KM, Arenkiel BR, Devine WP, Wythe JD. Multisite Assembly of Gateway Induced Clones (MAGIC): a flexible cloning toolbox with diverse applications in vertebrate model systems. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.13.603267. [PMID: 39026881 PMCID: PMC11257631 DOI: 10.1101/2024.07.13.603267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Here we present the Multisite Assembly of Gateway Induced Clones (MAGIC) system, which harnesses site-specific recombination-based cloning via Gateway technology for rapid, modular assembly of between 1 and 3 "Entry" vector components, all into a fourth, standard high copy "Destination" plasmid backbone. The MAGIC toolkit spans a range of in vitro and in vivo uses, from directing tunable gene expression, to driving simultaneous expression of microRNAs and fluorescent reporters, to enabling site-specific recombinase-dependent gene expression. All MAGIC system components are directly compatible with existing multisite gateway Tol2 systems currently used in zebrafish, as well as existing eukaryotic cell culture expression Destination plasmids, and available mammalian lentiviral and adenoviral Destination vectors, allowing rapid cross-species experimentation. Moreover, herein we describe novel vectors with flanking piggyBac transposon elements for stable genomic integration in vitro or in vivo when used with piggyBac transposase. Collectively, the MAGIC system facilitates transgenesis in cultured mammalian cells, electroporated mouse and chick embryos, as well as in injected zebrafish embryos, enabling the rapid generation of innovative DNA constructs for biological research due to a shared, common plasmid platform.
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2
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Saldana-Guerrero IM, Montano-Gutierrez LF, Boswell K, Hafemeister C, Poon E, Shaw LE, Stavish D, Lea RA, Wernig-Zorc S, Bozsaky E, Fetahu IS, Zoescher P, Pötschger U, Bernkopf M, Wenninger-Weinzierl A, Sturtzel C, Souilhol C, Tarelli S, Shoeb MR, Bozatzi P, Rados M, Guarini M, Buri MC, Weninger W, Putz EM, Huang M, Ladenstein R, Andrews PW, Barbaric I, Cresswell GD, Bryant HE, Distel M, Chesler L, Taschner-Mandl S, Farlik M, Tsakiridis A, Halbritter F. A human neural crest model reveals the developmental impact of neuroblastoma-associated chromosomal aberrations. Nat Commun 2024; 15:3745. [PMID: 38702304 PMCID: PMC11068915 DOI: 10.1038/s41467-024-47945-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 04/15/2024] [Indexed: 05/06/2024] Open
Abstract
Early childhood tumours arise from transformed embryonic cells, which often carry large copy number alterations (CNA). However, it remains unclear how CNAs contribute to embryonic tumourigenesis due to a lack of suitable models. Here we employ female human embryonic stem cell (hESC) differentiation and single-cell transcriptome and epigenome analysis to assess the effects of chromosome 17q/1q gains, which are prevalent in the embryonal tumour neuroblastoma (NB). We show that CNAs impair the specification of trunk neural crest (NC) cells and their sympathoadrenal derivatives, the putative cells-of-origin of NB. This effect is exacerbated upon overexpression of MYCN, whose amplification co-occurs with CNAs in NB. Moreover, CNAs potentiate the pro-tumourigenic effects of MYCN and mutant NC cells resemble NB cells in tumours. These changes correlate with a stepwise aberration of developmental transcription factor networks. Together, our results sketch a mechanistic framework for the CNA-driven initiation of embryonal tumours.
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Affiliation(s)
- Ingrid M Saldana-Guerrero
- Centre for Stem Cell Biology, School of Biosciences, The University of Sheffield, Sheffield, UK
- Neuroscience Institute, The University of Sheffield, Sheffield, UK
- Sheffield Institute for Nucleic Acids (SInFoNiA), School of Medicine and Population Health, The University of Sheffield, Sheffield, UK
| | | | - Katy Boswell
- Centre for Stem Cell Biology, School of Biosciences, The University of Sheffield, Sheffield, UK
- Neuroscience Institute, The University of Sheffield, Sheffield, UK
| | | | - Evon Poon
- Division of Clinical Studies, The Institute of Cancer Research (ICR) & Royal Marsden NHS Trust, London, UK
| | - Lisa E Shaw
- Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - Dylan Stavish
- Centre for Stem Cell Biology, School of Biosciences, The University of Sheffield, Sheffield, UK
- Neuroscience Institute, The University of Sheffield, Sheffield, UK
| | - Rebecca A Lea
- Centre for Stem Cell Biology, School of Biosciences, The University of Sheffield, Sheffield, UK
- Neuroscience Institute, The University of Sheffield, Sheffield, UK
| | - Sara Wernig-Zorc
- St. Anna Children's Cancer Research Institute (CCRI), Vienna, Austria
| | - Eva Bozsaky
- St. Anna Children's Cancer Research Institute (CCRI), Vienna, Austria
| | - Irfete S Fetahu
- St. Anna Children's Cancer Research Institute (CCRI), Vienna, Austria
- Medical University of Vienna, Department of Neurology, Division of Neuropathology and Neurochemistry, Vienna, Austria
| | - Peter Zoescher
- St. Anna Children's Cancer Research Institute (CCRI), Vienna, Austria
| | - Ulrike Pötschger
- St. Anna Children's Cancer Research Institute (CCRI), Vienna, Austria
| | - Marie Bernkopf
- St. Anna Children's Cancer Research Institute (CCRI), Vienna, Austria
- Labdia Labordiagnostik GmbH, Vienna, Austria
| | | | - Caterina Sturtzel
- St. Anna Children's Cancer Research Institute (CCRI), Vienna, Austria
| | - Celine Souilhol
- Centre for Stem Cell Biology, School of Biosciences, The University of Sheffield, Sheffield, UK
- Neuroscience Institute, The University of Sheffield, Sheffield, UK
- Biomolecular Sciences Research Centre, Department of Biosciences and Chemistry, Sheffield Hallam University, Sheffield, UK
| | - Sophia Tarelli
- Centre for Stem Cell Biology, School of Biosciences, The University of Sheffield, Sheffield, UK
- Neuroscience Institute, The University of Sheffield, Sheffield, UK
| | - Mohamed R Shoeb
- St. Anna Children's Cancer Research Institute (CCRI), Vienna, Austria
| | - Polyxeni Bozatzi
- St. Anna Children's Cancer Research Institute (CCRI), Vienna, Austria
| | - Magdalena Rados
- St. Anna Children's Cancer Research Institute (CCRI), Vienna, Austria
| | - Maria Guarini
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Michelle C Buri
- St. Anna Children's Cancer Research Institute (CCRI), Vienna, Austria
| | - Wolfgang Weninger
- Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - Eva M Putz
- St. Anna Children's Cancer Research Institute (CCRI), Vienna, Austria
| | - Miller Huang
- Children's Hospital Los Angeles, Cancer and Blood Disease Institutes, and The Saban Research Institute, Los Angeles, CA, USA
- Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Ruth Ladenstein
- St. Anna Children's Cancer Research Institute (CCRI), Vienna, Austria
| | - Peter W Andrews
- Centre for Stem Cell Biology, School of Biosciences, The University of Sheffield, Sheffield, UK
| | - Ivana Barbaric
- Centre for Stem Cell Biology, School of Biosciences, The University of Sheffield, Sheffield, UK
- Neuroscience Institute, The University of Sheffield, Sheffield, UK
| | | | - Helen E Bryant
- Sheffield Institute for Nucleic Acids (SInFoNiA), School of Medicine and Population Health, The University of Sheffield, Sheffield, UK
| | - Martin Distel
- St. Anna Children's Cancer Research Institute (CCRI), Vienna, Austria
| | - Louis Chesler
- Division of Clinical Studies, The Institute of Cancer Research (ICR) & Royal Marsden NHS Trust, London, UK
| | | | - Matthias Farlik
- Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - Anestis Tsakiridis
- Centre for Stem Cell Biology, School of Biosciences, The University of Sheffield, Sheffield, UK.
- Neuroscience Institute, The University of Sheffield, Sheffield, UK.
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3
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Zhu Y, Luo B, Mou X, Song Y, Zhou Y, Luo Y, Sun B, Luo Y, Tang H, Su Z, Bao R. Pseudomonas aeruginosa regulator PvrA binds simultaneously to multiple pseudo-palindromic sites for efficient transcription activation. SCIENCE CHINA. LIFE SCIENCES 2024; 67:900-912. [PMID: 37938507 DOI: 10.1007/s11427-022-2363-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 05/10/2023] [Indexed: 11/09/2023]
Abstract
Tetracycline repressor (TetR) family regulators (TFRs) are the largest group of DNA-binding transcription factors and are widely distributed in bacteria and archaea. TFRs play vital roles in controlling the expression of various genes and regulating diverse physiological processes. Recently, a TFR protein Pseudomonas virulence regulator A (PvrA), was identified from Pseudomonas aeruginosa as the transcriptional activator of genes involved in fatty acid utilization and bacterial virulence. Here, we show that PvrA can simultaneously bind to multiple pseudo-palindromic sites and upregulate the expression levels of target genes. Cryo-electron microscopy (cryo-EM) analysis indicates the simultaneous DNA recognition mechanism of PvrA and suggests that the bound DNA fragments consist of a distorted B-DNA double helix. The crystal structure and functional analysis of PvrA reveal a hinge region that secures the correct domain motion for recognition of the promiscuous promoter. Additionally, our results showed that mutations disrupting the regulatory hinge region have differential effects on biofilm formation and pyocyanin biosynthesis, resulting in attenuated bacterial virulence. Collectively, these findings will improve the understanding of the relationship between the structure and function of the TetR family and provide new insights into the mechanism of regulation of P. aeruginosa virulence.
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Affiliation(s)
- Yibo Zhu
- Center of Infectious Diseases, Division of Infectious Diseases in State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China
- Accurate Biotechnology (Hunan) Co., Ltd, Changsha, 410006, China
| | - Bingnan Luo
- Center of Infectious Diseases, Division of Infectious Diseases in State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Xingyu Mou
- Center of Infectious Diseases, Division of Infectious Diseases in State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Yingjie Song
- College of Life Science, Sichuan Normal University, Chengdu, 610101, China
| | - Yonghong Zhou
- Key Laboratory of Biodiversity and Environment on the Qinghai-Tibetan Plateau, Ministry of Education, School of Ecology and Environment, Tibet University, Lhasa, 850000, China
| | - Yongbo Luo
- Center of Infectious Diseases, Division of Infectious Diseases in State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Bo Sun
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201210, China
| | - Youfu Luo
- Center of Infectious Diseases, Division of Infectious Diseases in State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Hong Tang
- Center of Infectious Diseases, Division of Infectious Diseases in State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China.
| | - Zhaoming Su
- Center of Infectious Diseases, Division of Infectious Diseases in State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China.
- Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, China.
| | - Rui Bao
- Center of Infectious Diseases, Division of Infectious Diseases in State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China.
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De Carluccio G, Fusco V, di Bernardo D. Engineering a synthetic gene circuit for high-performance inducible expression in mammalian systems. Nat Commun 2024; 15:3311. [PMID: 38632224 PMCID: PMC11024104 DOI: 10.1038/s41467-024-47592-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 04/02/2024] [Indexed: 04/19/2024] Open
Abstract
Inducible gene expression systems can be used to control the expression of a gene of interest by means of a small-molecule. One of the most common designs involves engineering a small-molecule responsive transcription factor (TF) and its cognate promoter, which often results in a compromise between minimal uninduced background expression (leakiness) and maximal induced expression. Here, we focus on an alternative strategy using quantitative synthetic biology to mitigate leakiness while maintaining high expression, without modifying neither the TF nor the promoter. Through mathematical modelling and experimental validations, we design the CASwitch, a mammalian synthetic gene circuit based on combining two well-known network motifs: the Coherent Feed-Forward Loop (CFFL) and the Mutual Inhibition (MI). The CASwitch combines the CRISPR-Cas endoribonuclease CasRx with the state-of-the-art Tet-On3G inducible gene system to achieve high performances. To demonstrate the potentialities of the CASwitch, we apply it to three different scenarios: enhancing a whole-cell biosensor, controlling expression of a toxic gene and inducible production of Adeno-Associated Virus (AAV) vectors.
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Affiliation(s)
- Giuliano De Carluccio
- Telethon Institute of Genetics and Medicine, Naples, Italy
- University of Naples Federico II, Department of Chemical Materials and Industrial Engineering, Naples, Italy
- Institute for Medical Engineering and Science, MIT, Cambridge, MA, USA
| | - Virginia Fusco
- Telethon Institute of Genetics and Medicine, Naples, Italy
- University of Naples Federico II, Department of Chemical Materials and Industrial Engineering, Naples, Italy
| | - Diego di Bernardo
- Telethon Institute of Genetics and Medicine, Naples, Italy.
- University of Naples Federico II, Department of Chemical Materials and Industrial Engineering, Naples, Italy.
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Sato Y, Hayashi MT. Micronucleus is not a potent inducer of the cGAS/STING pathway. Life Sci Alliance 2024; 7:e202302424. [PMID: 38307626 PMCID: PMC10837050 DOI: 10.26508/lsa.202302424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 01/22/2024] [Accepted: 01/22/2024] [Indexed: 02/04/2024] Open
Abstract
Micronuclei (MN) have been associated with the innate immune response. The abrupt rupture of MN membranes results in the accumulation of cGAS, potentially activating STING and downstream interferon-responsive genes. However, direct evidence connecting MN and cGAS activation has been lacking. We have developed the FuVis2 reporter system, which enables the visualization of the cell nucleus carrying a single sister chromatid fusion and, consequently, MN. Using this FuVis2 reporter equipped with cGAS and STING reporters, we rigorously assessed the potency of cGAS activation by MN in individual living cells. Our findings reveal that cGAS localization to membrane-ruptured MN during interphase is infrequent, with cGAS primarily capturing MN during mitosis and remaining bound to cytosolic chromatin. We found that cGAS accumulation during mitosis neither activates STING in the subsequent interphase nor triggers the interferon response. Gamma-ray irradiation activates STING independently of MN formation and cGAS localization to MN. These results suggest that cGAS accumulation in cytosolic MN is not a robust indicator of its activation and that MN are not the primary trigger of the cGAS/STING pathway.
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Affiliation(s)
- Yuki Sato
- https://ror.org/02kpeqv85 Graduate School of Biostudies, Kyoto University, Kyoto, Japan
- https://ror.org/02kpeqv85 IFOM-KU Joint Research Laboratory, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Makoto T Hayashi
- https://ror.org/02kpeqv85 IFOM-KU Joint Research Laboratory, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- IFOM ETS, the AIRC Institute of Molecular Oncology, Milan, Italy
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6
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Nassauer L, Staecker H, Huang P, Renslo B, Goblet M, Harre J, Warnecke A, Schott JW, Morgan M, Galla M, Schambach A. Protection from cisplatin-induced hearing loss with lentiviral vector-mediated ectopic expression of the anti-apoptotic protein BCL-XL. MOLECULAR THERAPY. NUCLEIC ACIDS 2024; 35:102157. [PMID: 38450280 PMCID: PMC10915631 DOI: 10.1016/j.omtn.2024.102157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 02/15/2024] [Indexed: 03/08/2024]
Abstract
Cisplatin is a highly effective chemotherapeutic agent, but it can cause sensorineural hearing loss (SNHL) in patients. Cisplatin-induced ototoxicity is closely related to the accumulation of reactive oxygen species (ROS) and subsequent death of hair cells (HCs) and spiral ganglion neurons (SGNs). Despite various strategies to combat ototoxicity, only one therapeutic agent has thus far been clinically approved. Therefore, we have developed a gene therapy concept to protect cochlear cells from cisplatin-induced toxicity. Self-inactivating lentiviral (LV) vectors were used to ectopically express various antioxidant enzymes or anti-apoptotic proteins to enhance the cellular ROS scavenging or prevent apoptosis in affected cell types. In direct comparison, anti-apoptotic proteins mediated a stronger reduction in cytotoxicity than antioxidant enzymes. Importantly, overexpression of the most promising candidate, Bcl-xl, achieved an up to 2.5-fold reduction in cisplatin-induced cytotoxicity in HEI-OC1 cells, phoenix auditory neurons, and primary SGN cultures. BCL-XL protected against cisplatin-mediated tissue destruction in cochlear explants. Strikingly, in vivo application of the LV BCL-XL vector improved hearing and increased HC survival in cisplatin-treated mice. In conclusion, we have established a preclinical gene therapy approach to protect mice from cisplatin-induced ototoxicity that has the potential to be translated to clinical use in cancer patients.
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Affiliation(s)
- Larissa Nassauer
- Institute of Experimental Hematology, Hannover Medical School, 30625 Hannover, Germany
| | - Hinrich Staecker
- Department of Otolaryngology-Head and Neck Surgery, University of Kansas School of Medicine, Kansas City, KS 66160, USA
| | - Peixin Huang
- Department of Otolaryngology-Head and Neck Surgery, University of Kansas School of Medicine, Kansas City, KS 66160, USA
| | - Bryan Renslo
- Department of Otolaryngology-Head and Neck Surgery, University of Kansas School of Medicine, Kansas City, KS 66160, USA
| | - Madeleine Goblet
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, 30625 Hannover, Germany
- Cluster of Excellence “Hearing4all”, Hannover Medical School, 30625 Hannover, Germany
| | - Jennifer Harre
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, 30625 Hannover, Germany
- Cluster of Excellence “Hearing4all”, Hannover Medical School, 30625 Hannover, Germany
| | - Athanasia Warnecke
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, 30625 Hannover, Germany
- Cluster of Excellence “Hearing4all”, Hannover Medical School, 30625 Hannover, Germany
| | - Juliane W. Schott
- Institute of Experimental Hematology, Hannover Medical School, 30625 Hannover, Germany
| | - Michael Morgan
- Institute of Experimental Hematology, Hannover Medical School, 30625 Hannover, Germany
| | - Melanie Galla
- Institute of Experimental Hematology, Hannover Medical School, 30625 Hannover, Germany
| | - Axel Schambach
- Institute of Experimental Hematology, Hannover Medical School, 30625 Hannover, Germany
- Division of Hematology/Oncology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
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7
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O’Laughlin R, Tran Q, Lezia A, Ngamkanjanarat W, Emmanuele P, Hao N, Hasty J. A Standardized Set of MoClo-Compatible Inducible Promoter Systems for Tunable Gene Expression in Yeast. ACS Synth Biol 2024; 13:85-102. [PMID: 38079574 PMCID: PMC11283237 DOI: 10.1021/acssynbio.3c00184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2024]
Abstract
Small-molecule control of gene expression underlies the function of numerous engineered gene circuits that are capable of environmental sensing, computation, and memory. While many recently developed inducible promoters have been tailor-made for bacteria or mammalian cells, relatively few new systems have been built for Saccharomyces cerevisiae, limiting the scale of synthetic biology work that can be done in yeast. To address this, we created the yeast Tunable Expression Systems Toolkit (yTEST), which contains a set of five extensively characterized inducible promoter systems regulated by the small-molecules doxycycline (Dox), abscisic acid (ABA), danoprevir (DNV), 1-naphthaleneacetic acid (NAA), and 5-phenyl-indole-3-acetic acid (5-Ph-IAA). Assembly was made to be compatible with the modular cloning yeast toolkit (MoClo-YTK) to enhance the ease of use and provide a framework to benchmark and standardize each system. Using this approach, we built multiple systems with maximal expression levels greater than those of the strong constitutive TDH3 promoter. Furthermore, each of the five classes of systems could be induced at least 60-fold after a 6 h induction and the highest fold change observed was approximately 300. Thus, yTEST provides a reliable, diverse, and customizable set of inducible promoters to modulate gene expression in yeast for applications in synthetic biology, metabolic engineering, and basic research.
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Affiliation(s)
- Richard O’Laughlin
- Department of Bioengineering, University of California San Diego, La Jolla, California 92093, United States; Present Address: Present address: Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States (R.O.)
| | - Quoc Tran
- Department of Molecular Biology, School of Biological Sciences, University of California San Diego, La Jolla, California 92093, United States; Present Address: Present address: Molecular Engineering & Sciences Institute, Department of Electrical & Computer Engineering, University of Washington, Seattle, Washington 98195, United States (Q.T.)
| | - Andrew Lezia
- Department of Bioengineering, University of California San Diego, La Jolla, California 92093, United States
| | - Wasu Ngamkanjanarat
- Department of Bioengineering, University of California San Diego, La Jolla, California 92093, United States
| | - Philip Emmanuele
- Department of Bioengineering, University of California San Diego, La Jolla, California 92093, United States
| | - Nan Hao
- Department of Bioengineering, University of California San Diego, La Jolla, California 92093, United States; Department of Molecular Biology, School of Biological Sciences and Synthetic Biology Institute, University of California San Diego, La Jolla, California 92093, United States
| | - Jeff Hasty
- Department of Bioengineering, University of California San Diego, La Jolla, California 92093, United States; Department of Molecular Biology, School of Biological Sciences and Synthetic Biology Institute, University of California San Diego, La Jolla, California 92093, United States
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8
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Zhang J, Xiao Y, Zhang J, Yang Y, Zhang L, Liang F. Recent advances of engineered oncolytic viruses-based combination therapy for liver cancer. J Transl Med 2024; 22:3. [PMID: 38167076 PMCID: PMC10763442 DOI: 10.1186/s12967-023-04817-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Accepted: 12/18/2023] [Indexed: 01/05/2024] Open
Abstract
Liver cancer is a major malignant tumor, which seriously threatens human health and increases the economic burden on patients. At present, gene therapy has been comprehensively studied as an excellent therapeutic measure in liver cancer treatment. Oncolytic virus (OV) is a kind of virus that can specifically infect and kill tumor cells. After being modified by genetic engineering, the specificity of OV infection to tumor cells is increased, and its influence on normal cells is reduced. To date, OV has shown its effectiveness and safety in experimental and clinical studies on a variety of tumors. Thus, this review primarily introduces the current status of different genetically engineered OVs used in gene therapy for liver cancer, focuses on the application of OVs and different target genes for current liver cancer therapy, and identifies the problems encountered in OVs-based combination therapy and the corresponding solutions, which will provide new insights into the treatment of liver cancer.
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Affiliation(s)
- Junhe Zhang
- Institutes of Health Central Plains, Xinxiang Medical University, No. 601 Jinsui Road, Xinxiang, 453003, Henan Province, China.
- Henan Key Laboratory of Neurorestoratology, The First Affiliated Hospital of Xinxiang Medical University, Weihui, 453100, China.
- School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, 453003, China.
| | - Yunxi Xiao
- Institutes of Health Central Plains, Xinxiang Medical University, No. 601 Jinsui Road, Xinxiang, 453003, Henan Province, China
| | - Jie Zhang
- School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, 453003, China
| | - Yun Yang
- School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, 453003, China
| | - Liao Zhang
- Institutes of Health Central Plains, Xinxiang Medical University, No. 601 Jinsui Road, Xinxiang, 453003, Henan Province, China
| | - Fan Liang
- Institutes of Health Central Plains, Xinxiang Medical University, No. 601 Jinsui Road, Xinxiang, 453003, Henan Province, China
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9
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Azevedo MD, Prince N, Humbert-Claude M, Mesa-Infante V, Jeanneret C, Golzne V, De Matos K, Jamot BB, Magara F, Gonzalez-Hernandez T, Tenenbaum L. Oxidative stress induced by sustained supraphysiological intrastriatal GDNF delivery is prevented by dose regulation. Mol Ther Methods Clin Dev 2023; 31:101106. [PMID: 37766790 PMCID: PMC10520444 DOI: 10.1016/j.omtm.2023.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 09/06/2023] [Indexed: 09/29/2023]
Abstract
Despite its established neuroprotective effect on dopaminergic neurons and encouraging phase I results, intraputaminal GDNF administration failed to demonstrate significant clinical benefits in Parkinson's disease patients. Different human GDNF doses were delivered in the striatum of rats with a progressive 6-hydroxydopamine lesion using a sensitive doxycycline-regulated AAV vector. GDNF treatment was applied either continuously or intermittently (2 weeks on/2 weeks off) during 17 weeks. Stable reduction of motor impairments as well as increased number of dopaminergic neurons and striatal innervation were obtained with a GDNF dose equivalent to 3- and 10-fold the rat endogenous level. In contrast, a 20-fold increased GDNF level only temporarily provided motor benefits and neurons were not spared. Strikingly, oxidized DNA in the substantia nigra increased by 50% with 20-fold, but not 3-fold GDNF treatment. In addition, only low-dose GDNF allowed to preserve dopaminergic neuron cell size. Finally, aberrant dopaminergic fiber sprouting was observed with 20-fold GDNF but not at lower doses. Intermittent 20-fold GDNF treatment allowed to avoid toxicity and spare dopaminergic neurons but did not restore their cell size. Our data suggest that maintaining GDNF concentration under a threshold generating oxidative stress is a pre-requisite to obtain significant symptomatic relief and neuroprotection.
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Affiliation(s)
- Marcelo Duarte Azevedo
- Laboratory of Cellular and Molecular Neurotherapies, Center for Neuroscience Research, Clinical Neurosciences Department, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), 1011 Lausanne, Switzerland
| | - Naika Prince
- Laboratory of Cellular and Molecular Neurotherapies, Center for Neuroscience Research, Clinical Neurosciences Department, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), 1011 Lausanne, Switzerland
| | - Marie Humbert-Claude
- Laboratory of Cellular and Molecular Neurotherapies, Center for Neuroscience Research, Clinical Neurosciences Department, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), 1011 Lausanne, Switzerland
| | - Virginia Mesa-Infante
- Departamento de Ciencias Médicas Básicas, Facultad de Ciencias de la Salud, Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna, La Laguna, 38200 Tenerife, Spain
| | - Cheryl Jeanneret
- Laboratory of Cellular and Molecular Neurotherapies, Center for Neuroscience Research, Clinical Neurosciences Department, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), 1011 Lausanne, Switzerland
| | - Valentine Golzne
- Laboratory of Cellular and Molecular Neurotherapies, Center for Neuroscience Research, Clinical Neurosciences Department, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), 1011 Lausanne, Switzerland
| | - Kevin De Matos
- Laboratory of Cellular and Molecular Neurotherapies, Center for Neuroscience Research, Clinical Neurosciences Department, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), 1011 Lausanne, Switzerland
| | - Benjamin Boury Jamot
- Center for the Study of Behaviour, Department of Psychiatry, Lausanne University Hospital and University of Lausanne (CHUV-UNIL), 1008 Lausanne, Switzerland
| | - Fulvio Magara
- Center for the Study of Behaviour, Department of Psychiatry, Lausanne University Hospital and University of Lausanne (CHUV-UNIL), 1008 Lausanne, Switzerland
| | - Tomas Gonzalez-Hernandez
- Departamento de Ciencias Médicas Básicas, Facultad de Ciencias de la Salud, Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna, La Laguna, 38200 Tenerife, Spain
| | - Liliane Tenenbaum
- Laboratory of Cellular and Molecular Neurotherapies, Center for Neuroscience Research, Clinical Neurosciences Department, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), 1011 Lausanne, Switzerland
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10
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Shiokawa D, Sakai H, Koizumi M, Okimoto Y, Mori Y, Kanda Y, Ohata H, Honda H, Okamoto K. Elevated stress response marks deeply quiescent reserve cells of gastric chief cells. Commun Biol 2023; 6:1183. [PMID: 37985874 PMCID: PMC10662433 DOI: 10.1038/s42003-023-05550-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Accepted: 11/07/2023] [Indexed: 11/22/2023] Open
Abstract
Gastrointestinal tract organs harbor reserve cells, which are endowed with cellular plasticity and regenerate functional units in response to tissue damage. However, whether the reserve cells in gastrointestinal tract exist as long-term quiescent cells remain incompletely understood. In the present study, we systematically examine H2b-GFP label-retaining cells and identify a long-term slow-cycling population in the gastric corpus but not in other gastrointestinal organs. The label-retaining cells, which reside near the basal layers of the corpus, comprise a subpopulation of chief cells. The identified quiescent cells exhibit induction of Atf4 and its target genes including Atf3, a marker of paligenosis, and activation of the unfolded protein response, but do not show elevated expression of Troy, Lgr5, or Mist. External damage to the gastric mucosa induced by indomethacin treatment triggers proliferation of the quiescent Atf4+ population, indicating that the gastric corpus harbors a specific cell population that is primed to facilitate stomach regeneration.
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Affiliation(s)
- Daisuke Shiokawa
- Division of Molecular Pharmacology, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045, Japan
- Ehime University Hospital Translational Research Center, Shitsukawa, Toon, 791-0295, Ehime, Japan
| | - Hiroaki Sakai
- Advanced Comprehensive Research Organization, Teikyo University, 2-21-1 Kaga, Itabashi-ku, Tokyo, 173-0003, Japan
| | - Miho Koizumi
- Field of Human Disease Models, Major in Advanced Life Sciences and Medicine, Tokyo Women's Medical University, 81- Kawada-cho, Shinjuku-ku, 162-8666, Tokyo, Japan
| | - Yoshie Okimoto
- Advanced Comprehensive Research Organization, Teikyo University, 2-21-1 Kaga, Itabashi-ku, Tokyo, 173-0003, Japan
| | - Yutaro Mori
- Advanced Comprehensive Research Organization, Teikyo University, 2-21-1 Kaga, Itabashi-ku, Tokyo, 173-0003, Japan
| | - Yusuke Kanda
- Advanced Comprehensive Research Organization, Teikyo University, 2-21-1 Kaga, Itabashi-ku, Tokyo, 173-0003, Japan
| | - Hirokazu Ohata
- Advanced Comprehensive Research Organization, Teikyo University, 2-21-1 Kaga, Itabashi-ku, Tokyo, 173-0003, Japan
| | - Hiroaki Honda
- Field of Human Disease Models, Major in Advanced Life Sciences and Medicine, Tokyo Women's Medical University, 81- Kawada-cho, Shinjuku-ku, 162-8666, Tokyo, Japan.
| | - Koji Okamoto
- Advanced Comprehensive Research Organization, Teikyo University, 2-21-1 Kaga, Itabashi-ku, Tokyo, 173-0003, Japan.
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11
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Jewel D, Pham Q, Chatterjee A. Virus-assisted directed evolution of biomolecules. Curr Opin Chem Biol 2023; 76:102375. [PMID: 37542745 PMCID: PMC10870257 DOI: 10.1016/j.cbpa.2023.102375] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 07/01/2023] [Accepted: 07/02/2023] [Indexed: 08/07/2023]
Abstract
Directed evolution is a powerful technique that uses principles of natural evolution to enable the development of biomolecules with novel functions. However, the slow pace of natural evolution does not support the demand for rapidly generating new biomolecular functions in the laboratory. Viruses offer a unique path to design fast laboratory evolution experiments, owing to their innate ability to evolve much more rapidly than most living organisms, facilitated by a smaller genome size that tolerate a high frequency of mutations, as well as a fast rate of replication. These attributes offer a great opportunity to evolve various biomolecules by linking their activity to the replication of a suitable virus. This review highlights the recent advances in the application of virus-assisted directed evolution of designer biomolecules in both prokaryotic and eukaryotic cells.
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Affiliation(s)
- Delilah Jewel
- Department of Chemistry, Boston College, 2609 Beacon Street, Chestnut Hill, MA 02467, USA
| | - Quan Pham
- Department of Chemistry, Boston College, 2609 Beacon Street, Chestnut Hill, MA 02467, USA
| | - Abhishek Chatterjee
- Department of Chemistry, Boston College, 2609 Beacon Street, Chestnut Hill, MA 02467, USA.
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12
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Knudsen TE, Hamilton WB, Proks M, Lykkegaard M, Linneberg-Agerholm M, Nielsen AV, Perera M, Malzard LL, Trusina A, Brickman JM. A bipartite function of ESRRB can integrate signaling over time to balance self-renewal and differentiation. Cell Syst 2023; 14:788-805.e8. [PMID: 37633265 DOI: 10.1016/j.cels.2023.07.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 03/22/2023] [Accepted: 07/28/2023] [Indexed: 08/28/2023]
Abstract
Cooperative DNA binding of transcription factors (TFs) integrates the cellular context to support cell specification during development. Naive mouse embryonic stem cells are derived from early development and can sustain their pluripotent identity indefinitely. Here, we ask whether TFs associated with pluripotency evolved to directly support this state or if the state emerges from their combinatorial action. NANOG and ESRRB are key pluripotency factors that co-bind DNA. We find that when both factors are expressed, ESRRB supports pluripotency. However, when NANOG is absent, ESRRB supports a bistable culture of cells with an embryo-like primitive endoderm identity ancillary to pluripotency. The stoichiometry between NANOG and ESRRB allows quantitative titration of this differentiation, and in silico modeling of bipartite ESRRB activity suggests it safeguards plasticity in differentiation. Thus, the concerted activity of cooperative TFs can transform their effect to sustain intermediate cell identities and allow ex vivo expansion of immortal stem cells. A record of this paper's transparent peer review process is included in the supplemental information.
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Affiliation(s)
- Teresa E Knudsen
- The Novo Nordisk Foundation Center for Stem Cell Medicine (reNEW), University of Copenhagen, Copenhagen, Denmark
| | - William B Hamilton
- The Novo Nordisk Foundation Center for Stem Cell Medicine (reNEW), University of Copenhagen, Copenhagen, Denmark.
| | - Martin Proks
- The Novo Nordisk Foundation Center for Stem Cell Medicine (reNEW), University of Copenhagen, Copenhagen, Denmark
| | - Maria Lykkegaard
- The Novo Nordisk Foundation Center for Stem Cell Medicine (reNEW), University of Copenhagen, Copenhagen, Denmark
| | - Madeleine Linneberg-Agerholm
- The Novo Nordisk Foundation Center for Stem Cell Medicine (reNEW), University of Copenhagen, Copenhagen, Denmark
| | | | - Marta Perera
- The Novo Nordisk Foundation Center for Stem Cell Medicine (reNEW), University of Copenhagen, Copenhagen, Denmark
| | | | - Ala Trusina
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Joshua M Brickman
- The Novo Nordisk Foundation Center for Stem Cell Medicine (reNEW), University of Copenhagen, Copenhagen, Denmark.
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13
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Terron HM, Maranan DS, Burgard LA, LaFerla FM, Lane S, Leissring MA. A Dual-Function "TRE-Lox" System for Genetic Deletion or Reversible, Titratable, and Near-Complete Downregulation of Cathepsin D. Int J Mol Sci 2023; 24:ijms24076745. [PMID: 37047718 PMCID: PMC10095275 DOI: 10.3390/ijms24076745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 04/01/2023] [Accepted: 04/03/2023] [Indexed: 04/14/2023] Open
Abstract
Commonly employed methods for reversibly disrupting gene expression, such as those based on RNAi or CRISPRi, are rarely capable of achieving >80-90% downregulation, making them unsuitable for targeting genes that require more complete disruption to elicit a phenotype. Genetic deletion, on the other hand, while enabling complete disruption of target genes, often produces undesirable irreversible consequences such as cytotoxicity or cell death. Here we describe the design, development, and detailed characterization of a dual-function "TRE-Lox" system for effecting either (a) doxycycline (Dox)-mediated downregulation or (b) genetic deletion of a target gene-the lysosomal aspartyl protease cathepsin D (CatD)-based on targeted insertion of a tetracycline-response element (TRE) and two LoxP sites into the 5' end of the endogenous CatD gene (CTSD). Using an optimized reverse-tetracycline transrepressor (rtTR) variant fused with the Krüppel-associated box (KRAB) domain, we show that CatD expression can be disrupted by as much as 98% in mouse embryonic fibroblasts (MEFs). This system is highly sensitive to Dox (IC50 = 1.46 ng/mL) and results in rapid (t1/2 = 0.57 d) and titratable downregulation of CatD. Notably, even near-total disruption of CatD expression was completely reversed by withdrawal of Dox. As expected, transient expression of Cre recombinase results in complete deletion of the CTSD gene. The dual functionality of this novel system will facilitate future studies of the involvement of CatD in various diseases, particularly those attributable to partial loss of CatD function. In addition, the TRE-Lox approach should be applicable to the regulation of other target genes requiring more complete disruption than can be achieved by traditional methods.
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Affiliation(s)
- Heather M Terron
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA 92697, USA
| | - Derek S Maranan
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA 92697, USA
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697, USA
| | - Luke A Burgard
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA 92697, USA
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697, USA
| | - Frank M LaFerla
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA 92697, USA
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697, USA
| | - Shelley Lane
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA 92697, USA
| | - Malcolm A Leissring
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA 92697, USA
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14
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Larsen TV, Dybdal N, Daugaard TF, Lade-Keller J, Lin L, Sorensen BS, Nielsen AL. Examination of the Functional Relationship between PD-L1 DNA Methylation and mRNA Expression in Non-Small-Cell Lung Cancer. Cancers (Basel) 2023; 15:cancers15061909. [PMID: 36980795 PMCID: PMC10047551 DOI: 10.3390/cancers15061909] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 03/04/2023] [Accepted: 03/20/2023] [Indexed: 03/30/2023] Open
Abstract
Immunotherapy targeting the interaction between programmed cell death protein 1 (PD-1) and programmed death-ligand 1 (PD-L1) is a treatment option for patients with non-small-cell lung cancer (NSCLC). The expression of PD-L1 by the NSCLC cells determines treatment effectiveness, but the relationship between PD-L1 DNA methylation and expression has not been clearly described. We investigated PD-L1 DNA methylation, mRNA expression, and protein expression in NSCLC cell lines and tumor biopsies. We used clustered regularly interspaced short palindromic repeats-associated protein 9 (CRISPR-Cas9) to modify PD-L1 genetic contexts and endonuclease deficient Cas9 (dCas9) fusions with ten-eleven translocation methylcytosine dioxygenase 1 (TET1) and DNA (cytosine-5)-methyltransferase 3A (DNMT3A) to manipulate PD-L1 DNA methylation. In NSCLC cell lines, we identified specific PD-L1 CpG sites with methylation levels inversely correlated with PD-L1 mRNA expression. However, inducing PD-L1 mRNA expression with interferon-γ did not decrease the methylation level for these CpG sites, and using CRISPR-Cas9, we found that the CpG sites did not directly confer a negative regulation. dCas9-TET1 and dCas9-DNMT3A could induce PD-L1 hypo- and hyper-methylation, respectively, with the latter conferring a decrease in expression showing the functional impact of methylation. In NSCLC biopsies, the inverse correlation between the methylation and expression of PD-L1 was weak. We conclude that there is a regulatory link between PD-L1 DNA methylation and expression. However, since these measures are weakly associated, this study highlights the need for further research before PD-L1 DNA methylation can be implemented as a biomarker and drug target for measures to improve the effectiveness of PD-1/PD-L1 immunotherapy in NSCLC.
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Affiliation(s)
- Trine V Larsen
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark
| | - Nina Dybdal
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark
| | - Tina F Daugaard
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark
| | | | - Lin Lin
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark
| | - Boe S Sorensen
- Department of Clinical Biochemistry, Aarhus University Hospital, 8200 Aarhus, Denmark
- Department of Clinical Medicine, Aarhus University, 8000 Aarhus, Denmark
| | - Anders L Nielsen
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark
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15
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Chen X, Liu Z, Lou C, Guan Y, Ouyang Q, Xiang Y. Improving cooperativity of transcription activators by oligomerization domains in mammalian cells. Synth Syst Biotechnol 2023; 8:114-120. [PMID: 36605704 PMCID: PMC9804245 DOI: 10.1016/j.synbio.2022.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 12/12/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022] Open
Abstract
Cooperative activation is critical for the applications of synthetic biology in mammalian cells. In this study, we have developed cooperative transcription factor by fusing oligomerization domain in mammalian cells. Firstly, we demonstrated that two oligomerized domains (CI434 and CI) successfully improved transcription factor cooperativity in bacterial cells but failed to increase cooperativity in mammalian cells, possibly because the additional mammalian activation domain disrupted their oligomerization capability. Therefore, we chose a different type of oligomerized domain (CarHC), whose ability to oligomerize is not dependent on its C-terminal domains, to fuse with a transcription factor (RpaR) and activation domain (VTR3), forming a potential cooperative transcription activator RpaR-CarH-VTR3 for mammalian regulatory systems. Compared with RpaR-VTR3, the cooperativity of RpaR-CarH-VTR3 was significantly improved with higher Hill coefficient and a narrower input range in the inducible switch system in mammalian cells. Moreover, a mathematical model based on statistical mechanics model was developed and the simulation results supported the hypothesis that the tetramer of the CarH domain in mammalian cells was the reason for the cooperative capacity of RpaR-CarH-VTR3.
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Affiliation(s)
- Xinmao Chen
- School of Physics, Peking University, Beijing, 100871, China
| | - Ziming Liu
- Center for Cell and Gene Circuit Design, CAS Key Laboratory of Quantitative Engineering Biology, Guangdong Provincial Key Laboratory of Synthetic Genomics, Shenzhen Key Laboratory of Synthetic Genomics, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Chunbo Lou
- Center for Cell and Gene Circuit Design, CAS Key Laboratory of Quantitative Engineering Biology, Guangdong Provincial Key Laboratory of Synthetic Genomics, Shenzhen Key Laboratory of Synthetic Genomics, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Ying Guan
- School of Physics, Peking University, Beijing, 100871, China
- Department of Chemical Engineering, Tsinghua University, Beijing, 100871, China
- Center for Cell and Gene Circuit Design, CAS Key Laboratory of Quantitative Engineering Biology, Guangdong Provincial Key Laboratory of Synthetic Genomics, Shenzhen Key Laboratory of Synthetic Genomics, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Qi Ouyang
- School of Physics, Peking University, Beijing, 100871, China
| | - Yanhui Xiang
- Center for Cell and Gene Circuit Design, CAS Key Laboratory of Quantitative Engineering Biology, Guangdong Provincial Key Laboratory of Synthetic Genomics, Shenzhen Key Laboratory of Synthetic Genomics, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
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16
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Hughes AL, Szczurek AT, Kelley JR, Lastuvkova A, Turberfield AH, Dimitrova E, Blackledge NP, Klose RJ. A CpG island-encoded mechanism protects genes from premature transcription termination. Nat Commun 2023; 14:726. [PMID: 36759609 PMCID: PMC9911701 DOI: 10.1038/s41467-023-36236-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 01/23/2023] [Indexed: 02/11/2023] Open
Abstract
Transcription must be tightly controlled to regulate gene expression and development. However, our understanding of the molecular mechanisms that influence transcription and how these are coordinated in cells to ensure normal gene expression remains rudimentary. Here, by dissecting the function of the SET1 chromatin-modifying complexes that bind to CpG island-associated gene promoters, we discover that they play a specific and essential role in enabling the expression of low to moderately transcribed genes. Counterintuitively, this effect can occur independently of SET1 complex histone-modifying activity and instead relies on an interaction with the RNA Polymerase II-binding protein WDR82. Unexpectedly, we discover that SET1 complexes enable gene expression by antagonising premature transcription termination by the ZC3H4/WDR82 complex at CpG island-associated genes. In contrast, at extragenic sites of transcription, which typically lack CpG islands and SET1 complex occupancy, we show that the activity of ZC3H4/WDR82 is unopposed. Therefore, we reveal a gene regulatory mechanism whereby CpG islands are bound by a protein complex that specifically protects genic transcripts from premature termination, effectively distinguishing genic from extragenic transcription and enabling normal gene expression.
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Affiliation(s)
- Amy L Hughes
- Department of Biochemistry, University of Oxford, Oxford, UK
| | | | | | - Anna Lastuvkova
- Department of Biochemistry, University of Oxford, Oxford, UK
| | | | | | | | - Robert J Klose
- Department of Biochemistry, University of Oxford, Oxford, UK.
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17
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Lee C, Lee BH, Jung H, Lee C, Sung Y, Kim H, Kim J, Shim JY, Kim JI, Choi DI, Park HY, Kaang BK. Hippocampal engram networks for fear memory recruit new synapses and modify pre-existing synapses in vivo. Curr Biol 2023; 33:507-516.e3. [PMID: 36638799 DOI: 10.1016/j.cub.2022.12.038] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 12/07/2022] [Accepted: 12/14/2022] [Indexed: 01/14/2023]
Abstract
As basic units of neural networks, ensembles of synapses underlie cognitive functions such as learning and memory. These synaptic engrams show elevated synaptic density among engram cells following contextual fear memory formation. Subsequent analysis of the CA3-CA1 engram synapse revealed larger spine sizes, as the synaptic connectivity correlated with the memory strength. Here, we elucidate the synapse dynamics between CA3 and CA1 by tracking identical synapses at multiple time points by adapting two-photon microscopy and dual-eGRASP technique in vivo. After memory formation, synaptic connections between engram populations are enhanced in conjunction with synaptogenesis within the hippocampal network. However, extinction learning specifically correlated with the disappearance of CA3 engram to CA1 engram (E-E) synapses. We observed "newly formed" synapses near pre-existing synapses, which clustered CA3-CA1 engram synapses after fear memory formation. Overall, we conclude that dynamics at CA3 to CA1 E-E synapses are key sites for modification during fear memory states.
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Affiliation(s)
- Chaery Lee
- Department of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, South Korea
| | - Byung Hun Lee
- Department of Physics and Astronomy, College of Natural Sciences, Seoul National University, Seoul 08826, South Korea
| | - Hyunsu Jung
- Department of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, South Korea; Interdisciplinary Program in Neuroscience, Seoul National University, Seoul 08826, South Korea
| | - Chiwoo Lee
- Interdisciplinary Program in Neuroscience, Seoul National University, Seoul 08826, South Korea
| | - Yongmin Sung
- Department of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, South Korea
| | - Hyopil Kim
- Department of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, South Korea
| | - Jooyoung Kim
- Department of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, South Korea
| | - Jae Youn Shim
- Department of Physics and Astronomy, College of Natural Sciences, Seoul National University, Seoul 08826, South Korea
| | - Ji-Il Kim
- Department of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, South Korea
| | - Dong Il Choi
- Department of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, South Korea
| | - Hye Yoon Park
- Department of Physics and Astronomy, College of Natural Sciences, Seoul National University, Seoul 08826, South Korea; Department of Electrical and Computer Engineering, College of Science and Engineering, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Bong-Kiun Kaang
- Department of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, South Korea; Interdisciplinary Program in Neuroscience, Seoul National University, Seoul 08826, South Korea.
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18
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Garside GB, Sandoval M, Beronja S, Rudolph KL. Lentiviral in situ targeting of stem cells in unperturbed intestinal epithelium. BMC Biol 2023; 21:6. [PMID: 36627630 PMCID: PMC9832770 DOI: 10.1186/s12915-022-01466-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 11/16/2022] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Methods for the long-term in situ transduction of the unperturbed murine intestinal epithelium have not been developed in past research. Such a method could speed up functional studies and screens to identify genetic factors influencing intestinal epithelium biology. Here, we developed an efficient method achieving this long-sought goal. RESULTS We used ultrasound-guided microinjections to transduce the embryonic endoderm at day 8 (E8.0) in utero. The injection procedure can be completed in 20 min and had a 100% survival rate. By injecting a small volume (0.1-0.2 μl) of concentrated virus, single shRNA constructs as well as lentiviral libraries can successfully be transduced. The new method stably and reproducibly targets adult intestinal epithelium, as well as other endoderm-derived organs such as the lungs, pancreas, liver, stomach, and bladder. Postnatal analysis of young adult mice indicates that single transduced cells at E8.0 gave rise to crypt fields that were comprised of 20-30 neighbouring crypts per crypt-field at 90 days after birth. Lentiviral targeting of ApcMin/+ mutant and wildtype mice revealed that heterozygous loss of Apc function suppresses the developmental normal growth pattern of intestinal crypt fields. This suppression of crypt field sizes did not involve a reduction of the crypt number per field, indicating that heterozygous Apc loss impaired the growth of individual crypts within the fields. Lentiviral-mediated shRNA knockdown of p53 led to an approximately 20% increase of individual crypts per field in both Apc+/+ and ApcMin/+ mice, associating with an increase in crypt size in ApcMin/+ mice but a slight reduction in crypt size in Apc+/+ mice. Overall, p53 knockdown rescued the reduction in crypt field size in Apc-mutant mice but had no effect on crypt field size in wildtype mice. CONCLUSIONS This study develops a novel technique enabling robust and reproducible in vivo targeting of intestinal stem cells in situ in the unperturbed intestinal epithelium across different regions of the intestine. In vivo somatic gene editing and genetic screening of lentiviral libraries has the potential to speed up discoveries and mechanistic understanding of genetic pathways controlling the biology of the intestinal epithelium during development and postnatal life. The here developed method enables such approaches.
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Affiliation(s)
- George B. Garside
- Leibniz Institute on Aging, Fritz Lipmann Institute, 07745 Jena, Germany
- National Center for Tumor Diseases, 01307 Dresden, Germany
| | - Madeline Sandoval
- Division of Human Biology, Fred Hutchinson Cancer Center, Seattle, WA 98109 USA
| | - Slobodan Beronja
- Division of Human Biology, Fred Hutchinson Cancer Center, Seattle, WA 98109 USA
| | - K. Lenhard Rudolph
- Leibniz Institute on Aging, Fritz Lipmann Institute, 07745 Jena, Germany
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19
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Genomically mined acoustic reporter genes for real-time in vivo monitoring of tumors and tumor-homing bacteria. Nat Biotechnol 2023:10.1038/s41587-022-01581-y. [PMID: 36593411 DOI: 10.1038/s41587-022-01581-y] [Citation(s) in RCA: 38] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 10/20/2022] [Indexed: 01/03/2023]
Abstract
Ultrasound allows imaging at a much greater depth than optical methods, but existing genetically encoded acoustic reporters for in vivo cellular imaging have been limited by poor sensitivity, specificity and in vivo expression. Here we describe two acoustic reporter genes (ARGs)-one for use in bacteria and one for use in mammalian cells-identified through a phylogenetic screen of candidate gas vesicle gene clusters from diverse bacteria and archaea that provide stronger ultrasound contrast, produce non-linear signals distinguishable from background tissue and have stable long-term expression. Compared to their first-generation counterparts, these improved bacterial and mammalian ARGs produce 9-fold and 38-fold stronger non-linear contrast, respectively. Using these new ARGs, we non-invasively imaged in situ tumor colonization and gene expression in tumor-homing therapeutic bacteria, tracked the progression of tumor gene expression and growth in a mouse model of breast cancer, and performed gene-expression-guided needle biopsies of a genetically mosaic tumor, demonstrating non-invasive access to dynamic biological processes at centimeter depth.
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20
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Song J, Liu C, Li B, Liu L, Zeng L, Ye Z, Wu W, Zhu L, Hu B. Synthetic peptides for the precise transportation of proteins of interests to selectable subcellular areas. Front Bioeng Biotechnol 2023; 11:1062769. [PMID: 36890909 PMCID: PMC9986269 DOI: 10.3389/fbioe.2023.1062769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 02/09/2023] [Indexed: 02/22/2023] Open
Abstract
Proteins, as gifts from nature, provide structure, sequence, and function templates for designing biomaterials. As first reported here, one group of proteins called reflectins and derived peptides were found to present distinct intracellular distribution preferences. Taking their conserved motifs and flexible linkers as Lego bricks, a series of reflectin-derivates were designed and expressed in cells. The selective intracellular localization property leaned on an RMs (canonical conserved reflectin motifs)-replication-determined manner, suggesting that these linkers and motifs were constructional fragments and ready-to-use building blocks for synthetic design and construction. A precise spatiotemporal application demo was constructed in the work by integrating RLNto2 (as one representative of a synthetic peptide derived from RfA1) into the Tet-on system to effectively transport cargo peptides into nuclei at selective time points. Further, the intracellular localization of RfA1 derivatives was spatiotemporally controllable with a CRY2/CIB1 system. At last, the functional homogeneities of either motifs or linkers were verified, which made them standardized building blocks for synthetic biology. In summary, the work provides a modularized, orthotropic, and well-characterized synthetic-peptide warehouse for precisely regulating the nucleocytoplasmic localization of proteins.
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Affiliation(s)
- Junyi Song
- Department of Biology and Chemistry, College of Science, National University of Defense Technology, Changsha, Hunan, China
| | - Chuanyang Liu
- Department of Biology and Chemistry, College of Science, National University of Defense Technology, Changsha, Hunan, China
| | - Baoshan Li
- Department of Biology and Chemistry, College of Science, National University of Defense Technology, Changsha, Hunan, China
| | - Liangcheng Liu
- Department of Biology and Chemistry, College of Science, National University of Defense Technology, Changsha, Hunan, China
| | - Ling Zeng
- Department of Biology and Chemistry, College of Science, National University of Defense Technology, Changsha, Hunan, China
| | - Zonghuang Ye
- Department of Biology and Chemistry, College of Science, National University of Defense Technology, Changsha, Hunan, China
| | - Wenjian Wu
- Department of Biology and Chemistry, College of Science, National University of Defense Technology, Changsha, Hunan, China
| | - Lingyun Zhu
- Department of Biology and Chemistry, College of Science, National University of Defense Technology, Changsha, Hunan, China
| | - Biru Hu
- Department of Biology and Chemistry, College of Science, National University of Defense Technology, Changsha, Hunan, China
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21
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Tendon-Specific Activation of Tenogenic Transcription Factors Enables Keeping Tenocytes' Identity In Vitro. Int J Mol Sci 2022; 23:ijms232214078. [PMID: 36430562 PMCID: PMC9695818 DOI: 10.3390/ijms232214078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/11/2022] [Accepted: 11/12/2022] [Indexed: 11/18/2022] Open
Abstract
We generated a novel tetracycline-inducible transgenic mouse line with the tendon-specific expression of a series of tendon-critical transcription factors. Primary tenocytes derived from this mouse line consistently expressed green fluorescent protein reporter transcription factors in response to doxycycline. The tenocytes maintained their tendon cell properties for a longer time after the transient induction in the absence of growth factors and mechanical stress. Four key transcription factors for tendon development and the green fluorescent protein reporter were linked with different viral 2A self-cleaving peptides. They were expressed under the control of the tet-responsive element. In combination with the expression of BFP, which reports on the tendon-specific collagen I, and mScarlet, which reports on the tendon-specific transcription factor Scleraxis (Scx), we observed the more extended maintenance of the tendon cell identity of in vitro cultured tendon cells and Achilles tendon explants. This means that the Scleraxis bHLH transcription factor (Scx), mohawk homeobox (Mkx), early growth response 1 (Egr1) and early growth response 2 (Egr2) contributed to the maintenance of tenocytes' identity in vitro, providing a new model for studying extracellular matrix alterations and identifying alternative biomaterials in vitro.
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22
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Choi JE, Choi DI, Lee J, Kim J, Kim MJ, Hong I, Jung H, Sung Y, Kim JI, Kim T, Yu NK, Lee SH, Choe HK, Koo JW, Kim JH, Kaang BK. Synaptic ensembles between raphe and D 1R-containing accumbens shell neurons underlie postisolation sociability in males. SCIENCE ADVANCES 2022; 8:eabo7527. [PMID: 36223467 PMCID: PMC9555785 DOI: 10.1126/sciadv.abo7527] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 08/25/2022] [Indexed: 06/16/2023]
Abstract
Social animals expend considerable energy to maintain social bonds throughout their life. Male and female mice show sexually dimorphic behaviors, yet the underlying neural mechanisms of sociability and their dysregulation during social disconnection remain unknown. Dopaminergic neurons in dorsal raphe nucleus (DRNTH) is known to contribute to a loneliness-like state and modulate sociability. We identified that activated subpopulations in DRNTH and nucleus accumbens shell (NAcsh) during 24 hours of social isolation underlie the increase in isolation-induced sociability in male but not in female mice. This effect was reversed by chemogenetically and optogenetically inhibiting the DRNTH-NAcsh circuit. Moreover, synaptic connectivity among the activated neuronal ensembles in this circuit was increased, primarily in D1 receptor-expressing neurons in NAcsh. The increase in synaptic density functionally correlated with elevated dopamine release into NAcsh. Overall, specific synaptic ensembles in DRNTH-NAcsh mediate sex differences in isolation-induced sociability, indicating that sex-dependent circuit dynamics underlie the expression of sexually dimorphic behaviors.
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Affiliation(s)
- Ja Eun Choi
- School of Biological Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
| | - Dong Il Choi
- School of Biological Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
| | - Jisu Lee
- School of Biological Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
| | - Jooyoung Kim
- School of Biological Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
| | - Min Jung Kim
- School of Biological Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
| | - Ilgang Hong
- School of Biological Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
| | - Hyunsu Jung
- School of Biological Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
| | - Yongmin Sung
- School of Biological Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
| | - Ji-il Kim
- School of Biological Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
| | - TaeHyun Kim
- School of Biological Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
| | - Nam-Kyung Yu
- School of Biological Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
| | - Seung-Hee Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, South Korea
| | - Han Kyoung Choe
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333 Technojoongang-daero, Dalseong-gun, Daegu 42988, South Korea
| | - Ja Wook Koo
- Emotion, Cognition & Behavior Research Group, Korea Brain Research Institute, 61, Cheomdan-ro, Dong-gu, Daegu 41062, South Korea
| | - Joung-Hun Kim
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), 77, Cheongam-ro, Nam-Gu, Pohang 37673, South Korea
| | - Bong-Kiun Kaang
- School of Biological Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
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23
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Saunderson SC, Hosseini-Rad SMA, McLellan AD. Noise-Reduction and Sensitivity-Enhancement of a Sleeping Beauty-Based Tet-On System. Genes (Basel) 2022; 13:genes13101679. [PMID: 36292564 PMCID: PMC9602432 DOI: 10.3390/genes13101679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 09/15/2022] [Accepted: 09/15/2022] [Indexed: 11/16/2022] Open
Abstract
Tetracycline-inducible systems are widely used control elements for mammalian gene expression. Despite multiple iterations to improve inducibility, their use is still compromised by basal promoter activity in the absence of tetracyclines. In a mammalian system, we previously showed that the introduction of the G72V mutation in the rtTA-M2 tetracycline activator lowers the basal level expression and increases the fold-induction of multiple genetic elements in a long chimeric antigen receptor construct. In this study, we confirmed that the G72V mutation was effective in minimising background expression in the absence of an inducer, resulting in an increase in fold-expression. Loss of responsiveness due to the G72V mutation was compensated through the incorporation of four sensitivity enhancing (SE) mutations, without compromising promoter tightness. However, SE mutations alone (without G72V) led to undesirable leakiness. Although cryptic splice site removal from rtTA did not alter the inducible control of the luciferase reporter gene in this simplified vector system, this is still recommended as a precaution in more complex multi-gene elements that contain rtTA. The optimized expression construct containing G72V and SE mutations currently provides the best improvement of fold-induction mediated by the rtTA-M2 activator in a mammalian system.
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Affiliation(s)
- Sarah C. Saunderson
- Department of Microbiology and Immunology, University of Otago, Dunedin 9016, New Zealand
- Correspondence:
| | - SM Ali Hosseini-Rad
- Department of Microbiology and Immunology, University of Otago, Dunedin 9016, New Zealand
- Centre of Excellence in Immunology and Immune-Mediated Diseases, University of Chulalongkorn, Bangkok 10330, Thailand
| | - Alexander D. McLellan
- Department of Microbiology and Immunology, University of Otago, Dunedin 9016, New Zealand
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Gao S, Zhou J, Hu Z, Zhang S, Wu Y, Musunuru PP, Zhang T, Yang L, Luo X, Bai J, Meng Q, Yu R. Effects of the m6Am methyltransferase PCIF1 on cell proliferation and survival in gliomas. Biochim Biophys Acta Mol Basis Dis 2022; 1868:166498. [PMID: 35868483 DOI: 10.1016/j.bbadis.2022.166498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 07/11/2022] [Accepted: 07/13/2022] [Indexed: 10/31/2022]
Abstract
BACKGROUND Previous studies have suggested an important role for N6-methyladenosine (m6A) modification in the proliferation of glioma cells. N6, 2'-O-dimethyladenosine (m6Am) is another methylated form affecting the fate and function of most RNA. PCIF1 has recently been identified as the sole m6Am methyltransferase in mammalian mRNA. However, it remains unknown about the role of PCIF1 in the growth and survival of glioma cells. METHODS We constructed glioma cell lines that stably downregulated/upregulated PCIF1, established intracranial xenograft models using these cell lines, and employed the following methods for investigations: CCK-8, EdU, colony formation, flow cytometry, qRT-PCR, Western blot, and immunohistochemistry. FINDINGS Downregulating PCIF1 promoted glioma cell proliferation, while overexpressing PCIF1 showed the opposite effects. Overexpression of PCIF1 blocked cell cycle progression and induced apoptosis in glioma cells, which was further confirmed by alterations in the expression of cell checkpoint proteins and apoptotic markers. Interestingly, disruption of PCIF1 methyltransferase activity slightly reversed the effect of PCIF1 overexpression on cell proliferation, but had no significant reversal effects on cell cycle progression or apoptosis. Knockdown of PCIF1 promoted the growth of gliomas, while overexpressing PCIF1 inhibited tumor growth and prolonged the survival time of tumor-bearing mice. In addition, the mRNA and protein levels of PCIF1 were gradually decreased with the increase of WHO grade in glioma tissues, but there was no significant correlation with patient survival. INTERPRETATION These results indicated that PCIF1 played a suppressing role in glioma growth and survival, which may not entirely depend on its methyltransferase activity.
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Affiliation(s)
- Shangfeng Gao
- Department of Neurosurgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China; Institute of Nervous System Diseases, Xuzhou Medical University, Xuzhou 221002, China
| | - Junbo Zhou
- Department of Neurosurgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China; Institute of Nervous System Diseases, Xuzhou Medical University, Xuzhou 221002, China
| | - Zhiyuan Hu
- Department of Neurosurgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China; Institute of Nervous System Diseases, Xuzhou Medical University, Xuzhou 221002, China
| | - Shicheng Zhang
- Department of Neurosurgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China; Institute of Nervous System Diseases, Xuzhou Medical University, Xuzhou 221002, China
| | - Yue Wu
- Department of Neurosurgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China; Institute of Nervous System Diseases, Xuzhou Medical University, Xuzhou 221002, China
| | - Preethi Priyanka Musunuru
- Department of Neurosurgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China; Institute of Nervous System Diseases, Xuzhou Medical University, Xuzhou 221002, China
| | - Tong Zhang
- Department of Neurosurgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China
| | - Liquan Yang
- Department of Neurosurgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China; Institute of Nervous System Diseases, Xuzhou Medical University, Xuzhou 221002, China
| | - Xiang Luo
- Department of Neurosurgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China; Institute of Nervous System Diseases, Xuzhou Medical University, Xuzhou 221002, China
| | - Jin Bai
- Cancer Institute, Xuzhou Medical University, Xuzhou 221002, China.
| | - Qingming Meng
- Department of Neurosurgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China.
| | - Rutong Yu
- Department of Neurosurgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China; Institute of Nervous System Diseases, Xuzhou Medical University, Xuzhou 221002, China.
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25
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Amen AM, Loughran RM, Huang CH, Lew RJ, Ravi A, Guan Y, Schatoff EM, Dow LE, Emerling BM, Fellmann C. Endogenous spacing enables co-processing of microRNAs and efficient combinatorial RNAi. CELL REPORTS METHODS 2022; 2:100239. [PMID: 35880017 PMCID: PMC9308131 DOI: 10.1016/j.crmeth.2022.100239] [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] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 04/21/2022] [Accepted: 05/25/2022] [Indexed: 06/15/2023]
Abstract
We present Multi-miR, a microRNA-embedded shRNA system modeled after endogenous microRNA clusters that enables simultaneous expression of up to three or four short hairpin RNAs (shRNAs) from a single promoter without loss of activity, enabling robust combinatorial RNA interference (RNAi). We further developed complementary all-in-one vectors that are over one log-scale more sensitive to doxycycline-mediated activation in vitro than previous methods and resistant to shRNA inactivation in vivo. We demonstrate the utility of this system for intracranial expression of shRNAs in a glioblastoma model. Additionally, we leverage this platform to target the redundant RAF signaling node in a mouse model of KRAS-mutant cancer and show that robust combinatorial synthetic lethality efficiently abolishes tumor growth.
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Affiliation(s)
- Alexandra M. Amen
- Gladstone Institute of Data Science and Biotechnology, Gladstone Institutes, San Francisco, CA, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Ryan M. Loughran
- Cell and Molecular Biology of Cancer Program, Sanford Burnham Prebys, La Jolla, CA, USA
| | - Chun-Hao Huang
- Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Weill Cornell Graduate School of Medical Sciences, Weill Cornell Medicine, New York, NY, USA
| | - Rachel J. Lew
- Gladstone Institute of Data Science and Biotechnology, Gladstone Institutes, San Francisco, CA, USA
| | - Archna Ravi
- Cell and Molecular Biology of Cancer Program, Sanford Burnham Prebys, La Jolla, CA, USA
| | | | - Emma M. Schatoff
- Weill Cornell Graduate School of Medical Sciences, Weill Cornell Medicine, New York, NY, USA
- Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY, USA
| | - Lukas E. Dow
- Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY, USA
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA
| | - Brooke M. Emerling
- Cell and Molecular Biology of Cancer Program, Sanford Burnham Prebys, La Jolla, CA, USA
| | - Christof Fellmann
- Gladstone Institute of Data Science and Biotechnology, Gladstone Institutes, San Francisco, CA, USA
- Mirimus Inc., Brooklyn, NY, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA
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26
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Broadly Applicable, Virus-Free Dual Reporter Assay to Identify Compounds Interfering with Membrane Fusion: Performance for HSV-1 and SARS-CoV-2. Viruses 2022; 14:v14071354. [PMID: 35891336 PMCID: PMC9322530 DOI: 10.3390/v14071354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 06/13/2022] [Accepted: 06/19/2022] [Indexed: 02/04/2023] Open
Abstract
Membrane fusion constitutes an essential step in the replication cycle of numerous viral pathogens, hence it represents an important druggable target. In the present study, we established a virus-free, stable reporter fusion inhibition assay (SRFIA) specifically designed to identify compounds interfering with virus-induced membrane fusion. The dual reporter assay is based on two stable Vero cell lines harboring the third-generation tetracycline (Tet3G) transactivator and a bicistronic reporter gene cassette under the control of the tetracycline responsive element (TRE3G), respectively. Cell–cell fusion by the transient transfection of viral fusogens in the presence of doxycycline results in the expression of the reporter enzyme secreted alkaline phosphatase (SEAP) and the fluorescent nuclear localization marker EYFPNuc. A constitutively expressed, secreted form of nanoluciferase (secNLuc) functioned as the internal control. The performance of the SRFIA was tested for the quantification of SARS-CoV-2- and HSV-1-induced cell–cell fusion, respectively, showing high sensitivity and specificity, as well as the reliable identification of known fusion inhibitors. Parallel quantification of secNLuc enabled the detection of cytotoxic compounds or insufficient transfection efficacy. In conclusion, the SRFIA reported here is well suited for high-throughput screening for new antiviral agents and essentially will be applicable to all viral fusogens causing cell–cell fusion in Vero cells.
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27
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Yshii L, Pasciuto E, Bielefeld P, Mascali L, Lemaitre P, Marino M, Dooley J, Kouser L, Verschoren S, Lagou V, Kemps H, Gervois P, de Boer A, Burton OT, Wahis J, Verhaert J, Tareen SHK, Roca CP, Singh K, Whyte CE, Kerstens A, Callaerts-Vegh Z, Poovathingal S, Prezzemolo T, Wierda K, Dashwood A, Xie J, Van Wonterghem E, Creemers E, Aloulou M, Gsell W, Abiega O, Munck S, Vandenbroucke RE, Bronckaers A, Lemmens R, De Strooper B, Van Den Bosch L, Himmelreich U, Fitzsimons CP, Holt MG, Liston A. Astrocyte-targeted gene delivery of interleukin 2 specifically increases brain-resident regulatory T cell numbers and protects against pathological neuroinflammation. Nat Immunol 2022; 23:878-891. [PMID: 35618831 PMCID: PMC9174055 DOI: 10.1038/s41590-022-01208-z] [Citation(s) in RCA: 63] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 04/11/2022] [Indexed: 12/21/2022]
Abstract
The ability of immune-modulating biologics to prevent and reverse pathology has transformed recent clinical practice. Full utility in the neuroinflammation space, however, requires identification of both effective targets for local immune modulation and a delivery system capable of crossing the blood-brain barrier. The recent identification and characterization of a small population of regulatory T (Treg) cells resident in the brain presents one such potential therapeutic target. Here, we identified brain interleukin 2 (IL-2) levels as a limiting factor for brain-resident Treg cells. We developed a gene-delivery approach for astrocytes, with a small-molecule on-switch to allow temporal control, and enhanced production in reactive astrocytes to spatially direct delivery to inflammatory sites. Mice with brain-specific IL-2 delivery were protected in traumatic brain injury, stroke and multiple sclerosis models, without impacting the peripheral immune system. These results validate brain-specific IL-2 gene delivery as effective protection against neuroinflammation, and provide a versatile platform for delivery of diverse biologics to neuroinflammatory patients.
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Affiliation(s)
- Lidia Yshii
- VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Leuven, Belgium
- KU Leuven - Department of Neurosciences, Leuven, Belgium
| | - Emanuela Pasciuto
- VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Leuven, Belgium
- KU Leuven - Department of Neurosciences, Leuven, Belgium
| | - Pascal Bielefeld
- Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam, Netherlands
- Immunology Programme, The Babraham Institute, Babraham Research Campus, Cambridge, United Kingdom
| | - Loriana Mascali
- VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Leuven, Belgium
| | - Pierre Lemaitre
- VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Leuven, Belgium
| | - Marika Marino
- VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven - Department of Neurosciences, Leuven, Belgium
| | - James Dooley
- Immunology Programme, The Babraham Institute, Babraham Research Campus, Cambridge, United Kingdom
| | - Lubna Kouser
- Immunology Programme, The Babraham Institute, Babraham Research Campus, Cambridge, United Kingdom
| | - Stijn Verschoren
- VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven - Department of Neurosciences, Leuven, Belgium
| | - Vasiliki Lagou
- VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Leuven, Belgium
| | - Hannelore Kemps
- Cardio & Organ Systems (COST), Biomedical Research Institute (BIOMED), Hasselt University, Diepenbeek, Belgium
| | - Pascal Gervois
- Cardio & Organ Systems (COST), Biomedical Research Institute (BIOMED), Hasselt University, Diepenbeek, Belgium
| | - Antina de Boer
- VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven - Department of Neurosciences, Leuven, Belgium
| | - Oliver T Burton
- Immunology Programme, The Babraham Institute, Babraham Research Campus, Cambridge, United Kingdom
| | - Jérôme Wahis
- VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven - Department of Neurosciences, Leuven, Belgium
| | - Jens Verhaert
- VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven - Department of Neurosciences, Leuven, Belgium
| | - Samar H K Tareen
- Immunology Programme, The Babraham Institute, Babraham Research Campus, Cambridge, United Kingdom
| | - Carlos P Roca
- Immunology Programme, The Babraham Institute, Babraham Research Campus, Cambridge, United Kingdom
| | - Kailash Singh
- Immunology Programme, The Babraham Institute, Babraham Research Campus, Cambridge, United Kingdom
| | - Carly E Whyte
- Immunology Programme, The Babraham Institute, Babraham Research Campus, Cambridge, United Kingdom
| | - Axelle Kerstens
- VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven - Department of Neurosciences, Leuven, Belgium
- VIB Bio-Imaging Core, Leuven, Belgium
| | | | | | - Teresa Prezzemolo
- VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Leuven, Belgium
| | - Keimpe Wierda
- VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven - Department of Neurosciences, Leuven, Belgium
- VIB-KU Leuven Center for Brain & Disease Research, Electrophysiology Expertise Unit, Leuven, Belgium
| | - Amy Dashwood
- Immunology Programme, The Babraham Institute, Babraham Research Campus, Cambridge, United Kingdom
| | - Junhua Xie
- VIB Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Faculty of Sciences, Ghent University, Ghent, Belgium
| | - Elien Van Wonterghem
- VIB Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Faculty of Sciences, Ghent University, Ghent, Belgium
| | - Eline Creemers
- VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven - Department of Neurosciences, Leuven, Belgium
- VIB-KU Leuven Center for Brain & Disease Research, Electrophysiology Expertise Unit, Leuven, Belgium
| | - Meryem Aloulou
- Immunology Programme, The Babraham Institute, Babraham Research Campus, Cambridge, United Kingdom
- Toulouse Institute for Infectious and Inflammatory diseases (INFINITY), INSERM UMR1291, CNRS UMR 5051, Toulouse, France
| | - Willy Gsell
- KU Leuven, Department of Imaging and Pathology, Biomedical MRI, Leuven, Belgium
| | - Oihane Abiega
- Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam, Netherlands
| | - Sebastian Munck
- VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven - Department of Neurosciences, Leuven, Belgium
- VIB Bio-Imaging Core, Leuven, Belgium
| | - Roosmarijn E Vandenbroucke
- VIB Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Faculty of Sciences, Ghent University, Ghent, Belgium
| | - Annelies Bronckaers
- Cardio & Organ Systems (COST), Biomedical Research Institute (BIOMED), Hasselt University, Diepenbeek, Belgium
| | - Robin Lemmens
- VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven - Department of Neurosciences, Leuven, Belgium
- University Hospitals Leuven, Department of Neurology, Leuven, Belgium
| | - Bart De Strooper
- VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven - Department of Neurosciences, Leuven, Belgium
- Dementia Research Institute, University College London, London, United Kingdom
| | - Ludo Van Den Bosch
- VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven - Department of Neurosciences, Leuven, Belgium
| | - Uwe Himmelreich
- KU Leuven, Department of Imaging and Pathology, Biomedical MRI, Leuven, Belgium
| | - Carlos P Fitzsimons
- Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam, Netherlands
| | - Matthew G Holt
- VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium.
- KU Leuven - Department of Neurosciences, Leuven, Belgium.
- Instituto de Investigaçāo e Inovaçāo em Saúde (i3S), University of Porto, Porto, Portugal.
| | - Adrian Liston
- VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium.
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Leuven, Belgium.
- Immunology Programme, The Babraham Institute, Babraham Research Campus, Cambridge, United Kingdom.
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28
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DiAndreth B, Wauford N, Hu E, Palacios S, Weiss R. PERSIST platform provides programmable RNA regulation using CRISPR endoRNases. Nat Commun 2022; 13:2582. [PMID: 35562172 PMCID: PMC9095627 DOI: 10.1038/s41467-022-30172-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 04/20/2022] [Indexed: 12/26/2022] Open
Abstract
Regulated transgene expression is an integral component of gene therapies, cell therapies and biomanufacturing. However, transcription factor-based regulation, upon which most applications are based, suffers from complications such as epigenetic silencing that limit expression longevity and reliability. Constitutive transgene transcription paired with post-transcriptional gene regulation could combat silencing, but few such RNA- or protein-level platforms exist. Here we develop an RNA-regulation platform we call "PERSIST" which consists of nine CRISPR-specific endoRNases as RNA-level activators and repressors as well as modular OFF- and ON-switch regulatory motifs. We show that PERSIST-regulated transgenes exhibit strong OFF and ON responses, resist silencing for at least two months, and can be readily layered to construct cascades, logic functions, switches and other sophisticated circuit topologies. The orthogonal, modular and composable nature of this platform as well as the ease in constructing robust and predictable gene circuits promises myriad applications in gene and cell therapies.
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Affiliation(s)
- Breanna DiAndreth
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Noreen Wauford
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Eileen Hu
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Sebastian Palacios
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Ron Weiss
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
- Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
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29
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Islam A, Tom VJ. The use of viral vectors to promote repair after spinal cord injury. Exp Neurol 2022; 354:114102. [PMID: 35513025 DOI: 10.1016/j.expneurol.2022.114102] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 04/21/2022] [Accepted: 04/27/2022] [Indexed: 11/16/2022]
Abstract
Spinal cord injury (SCI) is a devastating event that can permanently disrupt multiple modalities. Unfortunately, the combination of the inhibitory environment at a central nervous system (CNS) injury site and the diminished intrinsic capacity of adult axons for growth results in the failure for robust axonal regeneration, limiting the ability for repair. Delivering genetic material that can either positively or negatively modulate gene expression has the potential to counter the obstacles that hinder axon growth within the spinal cord after injury. A popular gene therapy method is to deliver the genetic material using viral vectors. There are considerations when deciding on a viral vector approach for a particular application, including the type of vector, as well as serotypes, and promoters. In this review, we will discuss some of the aspects to consider when utilizing a viral vector approach to as a therapy for SCI. Additionally, we will discuss some recent applications of gene therapy to target extrinsic and/or intrinsic barriers to promote axon regeneration after SCI in preclinical models. While still in early stages, this approach has potential to treat those living with SCI.
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Affiliation(s)
- Ashraful Islam
- Drexel University College of Medicine, Department of Neurobiology and Anatomy, Marion Murray Spinal Cord Research Center, Philadelphia, PA, USA
| | - Veronica J Tom
- Drexel University College of Medicine, Department of Neurobiology and Anatomy, Marion Murray Spinal Cord Research Center, Philadelphia, PA, USA.
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30
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Characterization of an immune-evading doxycycline-inducible lentiviral vector for gene therapy in the spinal cord. Exp Neurol 2022; 355:114120. [DOI: 10.1016/j.expneurol.2022.114120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 05/12/2022] [Accepted: 05/17/2022] [Indexed: 11/18/2022]
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31
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Kelly RL, Huehls AM, Venkatachalam A, Huntoon CJ, Machida YJ, Karnitz LM. Intra-S phase checkpoint kinase Chk1 dissociates replication proteins Treslin and TopBP1 through multiple mechanisms during replication stress. J Biol Chem 2022; 298:101777. [PMID: 35231445 PMCID: PMC8965152 DOI: 10.1016/j.jbc.2022.101777] [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: 08/09/2021] [Revised: 02/17/2022] [Accepted: 02/19/2022] [Indexed: 11/17/2022] Open
Abstract
Replication stress impedes DNA polymerase progression causing activation of the ataxia telangiectasia and Rad3-related signaling pathway, which promotes the intra-S phase checkpoint activity through phosphorylation of checkpoint kinase 1 (Chk1). Chk1 suppresses replication origin firing, in part, by disrupting the interaction between the preinitiation complex components Treslin and TopBP1, an interaction that is mediated by TopBP1 BRCT domain-binding to two cyclin-dependent kinase (CDK) phosphorylation sites, T968 and S1000, in Treslin. Two nonexclusive models for how Chk1 regulates the Treslin–TopBP1 interaction have been proposed in the literature: in one model, these proteins dissociate due to a Chk1-induced decrease in CDK activity that reduces phosphorylation of the Treslin sites that bind TopBP1 and in the second model, Chk1 directly phosphorylates Treslin, resulting in dissociation of TopBP1. However, these models have not been formally examined. We show here that Treslin T968 phosphorylation was decreased in a Chk1-dependent manner, while Treslin S1000 phosphorylation was unchanged, demonstrating that T968 and S1000 are differentially regulated. However, CDK2-mediated phosphorylation alone did not fully account for Chk1 regulation of the Treslin–TopBP1 interaction. We also identified additional Chk1 phosphorylation sites on Treslin that contributed to disruption of the Treslin–TopBP1 interaction, including S1114. Finally, we showed that both of the proposed mechanisms regulate origin firing in cancer cell line models undergoing replication stress, with the relative roles of each mechanism varying among cell lines. This study demonstrates that Chk1 regulates Treslin through multiple mechanisms to promote efficient dissociation of Treslin and TopBP1 and furthers our understanding of Treslin regulation during the intra-S phase checkpoint.
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Affiliation(s)
- Rebecca L Kelly
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota, USA
| | - Amelia M Huehls
- Division of Oncology Research, Mayo Clinic, Rochester, Minnesota, USA
| | - Annapoorna Venkatachalam
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Yuichi J Machida
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota, USA; Division of Oncology Research, Mayo Clinic, Rochester, Minnesota, USA
| | - Larry M Karnitz
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota, USA; Division of Oncology Research, Mayo Clinic, Rochester, Minnesota, USA.
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32
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Hindul NL, Jhita A, Oprea DG, Hussain TA, Gonchar O, Campillo MAM, O'Regan L, Kanemaki MT, Fry AM, Hirota K, Tanaka K. Construction of a human hTERT RPE-1 cell line with inducible Cre for editing of endogenous genes. Biol Open 2022; 11:274087. [PMID: 35067715 PMCID: PMC8864296 DOI: 10.1242/bio.059056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 01/11/2022] [Indexed: 11/20/2022] Open
Abstract
The human retinal pigment epithelial RPE-1 cell line immortalized with hTERT retains a stable karyotype with a modal chromosome number of 46 and has been widely used to study physiological events in human cell culture systems. To facilitate inducible knock-out or knock-in experiments in this cell line, we have modified the AAVS1 locus to harbour a DNA fragment encoding ERT2-Cre-ERT2 fusion protein under regulation of a Tet-On expression system. In the generated cell line, active Cre recombinase was induced by simple addition of doxycycline and tamoxifen to the culture medium. As proof of concept, we successfully introduced an oncogenic point mutation to the endogenous KRAS gene locus of this cell line. The cell line will serve as a powerful tool to conduct functional analyses of human genes. Summary: A near wild-type human hTERT RPE-1 cell line with inducible Cre recombinase integrated at the AAVS1 was generated for inducible genetic knock-in and knock-out. It facilitates human gene functional studies.
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Affiliation(s)
- Naushin L. Hindul
- Department of Molecular and Cell Biology, University of Leicester, UK
| | - Amarjot Jhita
- Department of Molecular and Cell Biology, University of Leicester, UK
| | - Daiana G. Oprea
- Department of Molecular and Cell Biology, University of Leicester, UK
| | | | - Oksana Gonchar
- Department of Molecular and Cell Biology, University of Leicester, UK
| | | | - Laura O'Regan
- Department of Molecular and Cell Biology, University of Leicester, UK
| | - Masato T. Kanemaki
- Department of Chromosome Science, National Institute of Genetics, Research Organization of Information and Systems (ROIS), Yata 1111, Mishima, Shizuoka 411-8540, Japan
- Department of Genetics, SOKENDAI, Mishima, Shizuoka 411-8540, Japan
| | - Andrew M. Fry
- Department of Molecular and Cell Biology, University of Leicester, UK
| | - Kouji Hirota
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo, 192-0397, Japan
| | - Kayoko Tanaka
- Department of Molecular and Cell Biology, University of Leicester, UK
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33
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Kavaliauskaitė J, Kazlauskaitė A, Lazutka JR, Mozolevskis G, Stirkė A. Pulsed Electric Fields Alter Expression of NF-κB Promoter-Controlled Gene. Int J Mol Sci 2021; 23:ijms23010451. [PMID: 35008875 PMCID: PMC8745616 DOI: 10.3390/ijms23010451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 12/19/2021] [Accepted: 12/29/2021] [Indexed: 11/16/2022] Open
Abstract
The possibility to artificially adjust and fine-tune gene expression is one of the key milestones in bioengineering, synthetic biology, and advanced medicine. Since the effects of proteins or other transgene products depend on the dosage, controlled gene expression is required for any applications, where even slight fluctuations of the transgene product impact its function or other critical cell parameters. In this context, physical techniques demonstrate optimistic perspectives, and pulsed electric field technology is a potential candidate for a noninvasive, biophysical gene regulator, exploiting an easily adjustable pulse generating device. We exposed mammalian cells, transfected with a NF-κB pathway-controlled transcription system, to a range of microsecond-duration pulsed electric field parameters. To prevent toxicity, we used protocols that would generate relatively mild physical stimulation. The present study, for the first time, proves the principle that microsecond-duration pulsed electric fields can alter single-gene expression in plasmid context in mammalian cells without significant damage to cell integrity or viability. Gene expression might be upregulated or downregulated depending on the cell line and parameters applied. This noninvasive, ligand-, cofactor-, nanoparticle-free approach enables easily controlled direct electrostimulation of the construct carrying the gene of interest; the discovery may contribute towards the path of simplification of the complexity of physical systems in gene regulation and create further synergies between electronics, synthetic biology, and medicine.
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Affiliation(s)
- Justina Kavaliauskaitė
- Laboratory of Bioelectrics, Center for Physical Sciences and Technology, Sauletekio Ave. 3, LT-10257 Vilnius, Lithuania; (J.K.); (A.K.)
- Department of Botany and Genetics, Institute of Biosciences, Life Sciences Center, Vilnius University, Sauletekio Ave. 7, LT-10222 Vilnius, Lithuania;
| | - Auksė Kazlauskaitė
- Laboratory of Bioelectrics, Center for Physical Sciences and Technology, Sauletekio Ave. 3, LT-10257 Vilnius, Lithuania; (J.K.); (A.K.)
- Department of Botany and Genetics, Institute of Biosciences, Life Sciences Center, Vilnius University, Sauletekio Ave. 7, LT-10222 Vilnius, Lithuania;
| | - Juozas Rimantas Lazutka
- Department of Botany and Genetics, Institute of Biosciences, Life Sciences Center, Vilnius University, Sauletekio Ave. 7, LT-10222 Vilnius, Lithuania;
| | - Gatis Mozolevskis
- Laboratory of Prototyping of Electronic and Photonic Devices, Institute of Solid State Physics, University of Latvia, Kengaraga Str. 8, LV-1063 Riga, Latvia;
| | - Arūnas Stirkė
- Laboratory of Bioelectrics, Center for Physical Sciences and Technology, Sauletekio Ave. 3, LT-10257 Vilnius, Lithuania; (J.K.); (A.K.)
- Laboratory of Prototyping of Electronic and Photonic Devices, Institute of Solid State Physics, University of Latvia, Kengaraga Str. 8, LV-1063 Riga, Latvia;
- Correspondence:
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34
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Rommereim L, Akhade AS, Germain RN, Fraser IDC, Subramanian N. Lentivirus-mediated Conditional Gene Expression. Bio Protoc 2021; 11:e4205. [PMID: 34859120 PMCID: PMC8595424 DOI: 10.21769/bioprotoc.4205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 07/12/2021] [Accepted: 07/15/2021] [Indexed: 11/02/2022] Open
Abstract
The ability to identify the role of a particular gene within a system is dependent on control of the expression of that gene. In this protocol, we describe a method for stable, conditional expression of Nod-Like receptors (NLRs) in THP-1 cells using a lentiviral expression system. This system combines all the necessary components for tetracycline-inducible gene expression in a single lentivector with constitutive co-expression of a selection marker, which is an efficient means for controlling gene expression using a single viral infection of cells. This is done in a third generation lentiviral expression platform that improves the safety of lentiviruses and allows for greater gene expression than previous lentiviral platforms. The lentiviral expression plasmid is first engineered to contain the gene of interest driven by a TRE (tetracycline response element) promoter in a simple gateway cloning step and is then co-transfected into HEK293T cells, along with packaging and envelope plasmids to generate the virus. The virus is used to infect a cell type of interest at a low MOI so that the majority of the transduced cells contain a single viral integration. Infected cells are grown under selection, and viral integration is validated by qPCR. Gene expression in stably transduced cells is induced with doxycycline and validated by qPCR, immunoblot, and flow cytometry. This flexible lentiviral expression platform may be used for stable and robust induction of a gene of interest in a range of cells for multiple applications. Graphic abstract: Schematic overview of lentiviral transduction of THP-1 cells.
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Affiliation(s)
| | | | - Ronald N Germain
- Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20692-0421, USA
| | - Iain D C Fraser
- Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20692-0421, USA
| | - Naeha Subramanian
- Institute for Systems Biology, Seattle, USA.,Department of Immunology, University of Washington, Seattle, USA.,Department of Global Health, University of Washington, Seattle, USA
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35
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De Boeck J, Verfaillie C. Doxycycline inducible overexpression systems: how to induce your gene of interest without inducing misinterpretations. Mol Biol Cell 2021; 32:1517-1522. [PMID: 34383558 PMCID: PMC8351744 DOI: 10.1091/mbc.e21-04-0177] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
The doxycycline inducible overexpression system is a highly flexible and widely used tool for both in vitro and in vivo studies. However, during the past decade, a handful of reports have explicitly called for caution when using this system. The raised concerns are based on the notion that doxycycline can impair mitochondrial function of mammalian cells and can alter properties such as cell proliferation. As such, experimental outcomes can be confounded with the side effects of doxycycline and valid interpretation can be seriously threatened. Today, no consensus seems to exist about how these problems should be prevented. Moreover, some of the strategies that have been used to cope with these difficulties can actually introduce additional problems that are related to genomic instability and genetic modification of the cells. Here, we elaborate on the above statements and clarify them by some basic examples taken from our personal wet-lab experience. As such, we provide a nuanced overview of the doxycycline inducible overexpression system, some of its limitations and how to deal with them.
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Affiliation(s)
- Jolan De Boeck
- Department of Development and Regeneration, Stem Cell Institute, KU Leuven, Leuven 3000, Belgium
| | - Catherine Verfaillie
- Department of Development and Regeneration, Stem Cell Institute, KU Leuven, Leuven 3000, Belgium
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36
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Generation of a Tetracycline Regulated Mouse Model of MYC-Induced T-Cell Acute Lymphoblastic Leukemia. Methods Mol Biol 2021. [PMID: 34019298 DOI: 10.1007/978-1-0716-1476-1_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/28/2023]
Abstract
The tetracycline regulatory system provides a tractable strategy to interrogate the role of oncogenes in the initiation, maintenance, and regression of tumors through both spatial and temporal control of expression. This approach has several potential advantages over conventional methods to generate genetically engineered mouse models. First, continuous constitutive overexpression of an oncogene can be lethal to the host impeding further study. Second, constitutive overexpression fails to model adult onset of disease. Third, constitutive deletion does not permit, whereas conditional overexpression of an oncogene enables the study of the consequences of restoring expression of an oncogene back to endogenous levels. Fourth, the conditional activation of oncogenes enables examination of specific and/or developmental state-specific consequences.Hence, by allowing precise control of when and where a gene is expressed, the tetracycline regulatory system provides an ideal approach for the study of putative oncogenes in the initiation as well as the maintenance of tumorigenesis and the examination of the mechanisms of oncogene addiction. In this protocol, we describe the methods involved in the development of a conditional mouse model of MYC-induced T-cell acute lymphoblastic leukemia.
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37
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Transfer to the clinic: refining forward programming of hPSCs to megakaryocytes for platelet production in bioreactors. Blood Adv 2021; 5:1977-1990. [PMID: 33843988 DOI: 10.1182/bloodadvances.2020003236] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 01/20/2021] [Indexed: 12/29/2022] Open
Abstract
The production of in vitro-derived platelets has great potential for transfusion medicine. Here, we build on our experience in the forward programming (FoP) of human pluripotent stem cells (hPSCs) to megakaryocytes (MKs) and address several aspects of the complex challenges to bring this technology to the bedside. We first identify clinical-grade hPSC lines that generate MKs efficiently. We design a bespoke media to maximize both production and maturity of MKs and improve platelet output. Crucially, we transition the lentiviral-based FoP of hPSCs to a nonviral inducible system. We also show how small molecules promote a definitive hematopoiesis phenotype during the differentiation process, thereby increasing the quality of the final product. Finally, we generate platelets using a bioreactor designed to reproduce the physical cues that promote platelet production in the bone marrow. We show that these platelets are able to contribute to both thrombus formation in vitro and have a hemostatic effect in thrombocytopenic mice in vivo.
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38
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Michalec-Wawiórka B, Czapiński J, Filipek K, Rulak P, Czerwonka A, Tchórzewski M, Rivero-Müller A. An Improved Vector System for Homogeneous and Stable Gene Regulation. Int J Mol Sci 2021; 22:ijms22105206. [PMID: 34069024 PMCID: PMC8157167 DOI: 10.3390/ijms22105206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 04/24/2021] [Accepted: 05/08/2021] [Indexed: 11/16/2022] Open
Abstract
Precise analysis of the genetic expression and functioning of proteins requires experimental approaches that, among others, enable tight control of gene expression at the transcriptional level. Doxycycline-induced Tet-On/Tet-Off expression systems provide such an opportunity, and are frequently used to regulate the activity of genes in eukaryotic cells. Since its development, the Tet-system has evolved tight gene control in mammalian cells; however, some challenges are still unaddressed. In the current set up, the establishment of the standard Tet-based system in target cells is time-consuming and laborious and has been shown to be inefficient, especially in a long-term perspective. In this work, we present an optimized inducible expression system, which enables rapid generation of doxycycline-responsive cells according to a one- or two-step protocol. The reported modifications of the Tet-On system expand the toolbox for regulated mammalian gene expression and provide high, stable, and homogenous expression of the Tet-On3G transactivator, which is of fundamental importance in the regulation of transgenes.
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Affiliation(s)
- Barbara Michalec-Wawiórka
- Department of Molecular Biology, Institute of Biological Sciences, Maria Curie-Skłodowska University, 20-033 Lublin, Poland; (K.F.); (P.R.); (M.T.)
- Correspondence:
| | - Jakub Czapiński
- Department of Biochemistry and Molecular Biology, Medical University of Lublin, 20-093 Lublin, Poland; (J.C.); (A.C.); (A.R.-M.)
- Postgraduate School of Molecular Medicine, 02-091 Warsaw, Poland
| | - Kamil Filipek
- Department of Molecular Biology, Institute of Biological Sciences, Maria Curie-Skłodowska University, 20-033 Lublin, Poland; (K.F.); (P.R.); (M.T.)
| | - Patrycja Rulak
- Department of Molecular Biology, Institute of Biological Sciences, Maria Curie-Skłodowska University, 20-033 Lublin, Poland; (K.F.); (P.R.); (M.T.)
| | - Arkadiusz Czerwonka
- Department of Biochemistry and Molecular Biology, Medical University of Lublin, 20-093 Lublin, Poland; (J.C.); (A.C.); (A.R.-M.)
| | - Marek Tchórzewski
- Department of Molecular Biology, Institute of Biological Sciences, Maria Curie-Skłodowska University, 20-033 Lublin, Poland; (K.F.); (P.R.); (M.T.)
| | - Adolfo Rivero-Müller
- Department of Biochemistry and Molecular Biology, Medical University of Lublin, 20-093 Lublin, Poland; (J.C.); (A.C.); (A.R.-M.)
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39
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Expression of Secreted Neutrophil Gelatinase-Associated Lipocalin in 293T Cell Using the Inducible Dual-Function System. Processes (Basel) 2021. [DOI: 10.3390/pr9050855] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Neutrophil gelatinase-associated lipocalin (NGAL) has emerged as a promising biomarker for the early prediction of acute kidney injury (AKI). The production of recombinant NGAL is considered to be necessary for the development of a detection method. This study intended to express the recombinant NGAL protein in 293T cell under the Tet-On inducible system and human serum albumin signal sequence (HSA-SS). The transfection efficiency and protein modulation were assessed by detecting the expression of the enhanced green fluorescent protein (EGFP) and secreted NGAL protein. Both proteins were detected only in the presence of a doxycycline (Dox) inducer. Cell toxicity was not found under any conditions. Moreover, a higher level of soluble NGAL protein in the supernatant secreted by HSA-SS compared with a native signal peptide (Nat-SS) was observed. In summary, this work successfully optimized the conditions for induction of NGAL expression. This system will provide as an efficient strategy to produce other recombinant proteins secreted from a mammalian cell.
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40
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Tilley L, Papadopoulos SC, Pende M, Fei JF, Murawala P. The use of transgenics in the laboratory axolotl. Dev Dyn 2021; 251:942-956. [PMID: 33949035 DOI: 10.1002/dvdy.357] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 03/10/2021] [Accepted: 04/29/2021] [Indexed: 11/09/2022] Open
Abstract
The ability to generate transgenic animals sparked a wave of research committed to implementing such technology in a wide variety of model organisms. Building a solid base of ubiquitous and tissue-specific reporter lines has set the stage for later interrogations of individual cells or genetic elements. Compared to other widely used model organisms such as mice, zebrafish and fruit flies, there are only a few transgenic lines available in the laboratory axolotl (Ambystoma mexicanum), although their number is steadily expanding. In this review, we discuss a brief history of the transgenic methodologies in axolotl and their advantages and disadvantages. Next, we discuss available transgenic lines and insights we have been able to glean from them. Finally, we list challenges when developing transgenic axolotl, and where further work is needed in order to improve their standing as both a developmental and regenerative model.
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Affiliation(s)
- Lydia Tilley
- Mount Desert Island Biological Laboratory (MDIBL), Salisbury Cove, Maine, USA
| | - Sofia-Christina Papadopoulos
- Mount Desert Island Biological Laboratory (MDIBL), Salisbury Cove, Maine, USA.,Clinic for Kidney and Hypertension Diseases, Hannover Medical School, Hannover, Germany
| | - Marko Pende
- Mount Desert Island Biological Laboratory (MDIBL), Salisbury Cove, Maine, USA
| | - Ji-Feng Fei
- Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,Institute for Brain Research and Rehabilitation, South China Normal University, Guangzhou, China
| | - Prayag Murawala
- Mount Desert Island Biological Laboratory (MDIBL), Salisbury Cove, Maine, USA.,Clinic for Kidney and Hypertension Diseases, Hannover Medical School, Hannover, Germany
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41
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Spector LP, Tiffany M, Ferraro NM, Abell NS, Montgomery SB, Kay MA. Evaluating the Genomic Parameters Governing rAAV-Mediated Homologous Recombination. Mol Ther 2021; 29:1028-1046. [PMID: 33248247 PMCID: PMC7934627 DOI: 10.1016/j.ymthe.2020.11.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 10/16/2020] [Accepted: 11/18/2020] [Indexed: 12/26/2022] Open
Abstract
Recombinant adeno-associated virus (rAAV) vectors have the unique ability to promote targeted integration of transgenes via homologous recombination at specified genomic sites, reaching frequencies of 0.1%-1%. We studied genomic parameters that influence targeting efficiencies on a large scale. To do this, we generated more than 1,000 engineered, doxycycline-inducible target sites in the human HAP1 cell line and infected this polyclonal population with a library of AAV-DJ targeting vectors, with each carrying a unique barcode. The heterogeneity of barcode integration at each target site provided an assessment of targeting efficiency at that locus. We compared targeting efficiency with and without target site transcription for identical chromosomal positions. Targeting efficiency was enhanced by target site transcription, while chromatin accessibility was associated with an increased likelihood of targeting. ChromHMM chromatin states characterizing transcription and enhancers in wild-type K562 cells were also associated with increased AAV-HR efficiency with and without target site transcription, respectively. Furthermore, the amenability of a site to targeting was influenced by the endogenous transcriptional level of intersecting genes. These results define important parameters that may not only assist in designing optimal targeting vectors for genome editing, but also provide new insights into the mechanism of AAV-mediated homologous recombination.
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Affiliation(s)
- Laura P Spector
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Matthew Tiffany
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA; Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA
| | - Nicole M Ferraro
- Biomedical Informatics Program, Stanford University School of Medicine, Stanford, CA, USA
| | - Nathan S Abell
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Stephen B Montgomery
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA; Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
| | - Mark A Kay
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA; Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA.
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42
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Onaran HO, Costa T. Conceptual and experimental issues in biased agonism. Cell Signal 2021; 82:109955. [PMID: 33607257 DOI: 10.1016/j.cellsig.2021.109955] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 01/20/2021] [Accepted: 02/14/2021] [Indexed: 12/31/2022]
Abstract
In this review, we discuss the theoretical and experimental foundations for assessing agonism in the context of signalling bias in GPCRs. We show that the formulation of efficacy in classical receptor theory and the definition of ligand-induced allosteric effect in chemical thermodynamics are coincident measures of agonism, only if we recognize that the classical model cannot be considered as a mechanistic description of the physicochemical events underlying ligand-receptor signalling. It represents instead a mathematical tool, fortuitously capable of extracting efficacy information from concentration-dependent functional data, where both ligand-dependent and ligand-independent information are present. We also assert that dissecting efficacy from affinity, as originally advocated in classical theory, is imperative for understanding the molecular property underlying agonism, and the biased agonism that leads to preferential formation of diverse GPCR-transducer complexes. Finally, we argue that beyond the assumed translational value of functional selectivity (i.e. signalling bias), the identification of ligands with true bias of efficacy is of fundamental importance for unravelling the conformational space that determines the complex functional chemistry of GPCRs.
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Affiliation(s)
- H Ongun Onaran
- Ankara University, Faculty of Medicine, Department of Pharmacology, Molecular Biology and Technology Development Unit, Ankara, Turkey.
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Owens LV, Benedetto A, Dawson N, Gaffney CJ, Parkin ET. Gene therapy-mediated enhancement of protective protein expression for the treatment of Alzheimer's disease. Brain Res 2021; 1753:147264. [PMID: 33422539 DOI: 10.1016/j.brainres.2020.147264] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 11/22/2020] [Accepted: 12/20/2020] [Indexed: 12/30/2022]
Abstract
Alzheimer's disease (AD) is the leading form of dementia but lacks curative treatments. Current understanding of AD aetiology attributes the development of the disease to the misfolding of two proteins; amyloid-β (Aβ) and hyperphosphorylated tau, with their pathological accumulation leading to concomitant oxidative stress, neuroinflammation, and neuronal death. These processes are regulated at multiple levels to maintain homeostasis and avert disease. However, many of the relevant regulatory proteins appear to be downregulated in the AD-afflicted brain. Enhancement/restoration of these 'protective' proteins, therefore, represents an attractive therapeutic avenue. Gene therapy is a desirable means of achieving this because it is not associated with the side-effects linked to systemic protein administration, and sustained protein expression virtually eliminates compliance issues. The current article represents a focused and succinct review of the better established 'protective' protein targets for gene therapy enhancement/restoration rather than being designed as an exhaustive review incorporating less validated protein subjects. In addition, we will discuss how the risks associated with uncontrolled or irreversible gene expression might be mitigated through combining neuronal-specific promoters, inducible expression systems and localised injections. Whilst many of the gene therapy targets reviewed herein are yet to enter clinical trials, preclinical testing has thus far demonstrated encouraging potential for the gene therapy-based treatment of AD.
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Affiliation(s)
- Lauren V Owens
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YG, UK
| | - Alexandre Benedetto
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YG, UK
| | - Neil Dawson
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YG, UK
| | - Christopher J Gaffney
- Lancaster Medical School, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YG, UK
| | - Edward T Parkin
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YG, UK.
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Zhou Y, Lei C, Zhu Z. A low-background Tet-On system based on post-transcriptional regulation using Csy4. PLoS One 2020; 15:e0244732. [PMID: 33378396 PMCID: PMC7773235 DOI: 10.1371/journal.pone.0244732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 12/15/2020] [Indexed: 12/04/2022] Open
Abstract
On account of its stringent regulation and high rate of induction, the tetracycline regulatory system is used extensively for inducing target gene expression in eukaryotes. However, under certain circumstances, its associated background expression can be problematic, as in the expression of highly toxic proteins. We found that when using the Tet-On 3G system to drive expression of the kid toxin gene in sf9 insect cells, a higher percentage of cells were killed than when using an empty vector in the absence of the induction agent doxycycline, thereby indicating the leaky expression of this inducible expression system. Moreover, we found that the tetracycline-controlled transcriptional silencer (tTS) does not effectively reduce the background expression of the Tet-On 3G system in sf9 cells. However, Csy4, a Cas9 homologous protein in the CRISPR family with sequence-specific endonuclease activity, was found to be effective in reducing the Tet-On 3G system-associated background expression, although there was a concomitant reduction in the maximum induced expression. Nevertheless, we found that modification of the system via incorporation of TRE-controlled anti-sense csy4 in combination with a WSSVie1 (Δ23) promotor-driven sense csy4 significantly reduced the leaky expression of the Tet-On 3G system, and that the level of induction was higher than that initially obtained. This optimized Tet-On 3G system can significantly reduce cell death attributed to the background expression of Kid under uninduced conditions. Therefore, we developed a novel low-background inducible expression system for use in insect cells and potentially in other organisms including mammals based on post-transcriptional regulation using Csy4.
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Affiliation(s)
- Yicheng Zhou
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Chaoliang Lei
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Zhihui Zhu
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, Hubei, China
- * E-mail:
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Ahmed HMM, Heese F, Wimmer EA. Improvement on the genetic engineering of an invasive agricultural pest insect, the cherry vinegar fly, Drosophila suzukii. BMC Genet 2020; 21:139. [PMID: 33339511 PMCID: PMC7747376 DOI: 10.1186/s12863-020-00940-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Background The invasive fly Drosophila suzukii has become an established fruit pest in Europe, the USA, and South America with no effective and safe pest management. Genetic engineering enables the development of transgene-based novel genetic control strategies against insect pests and disease vectors. This, however, requires the establishment of reliable germline transformation techniques. Previous studies have shown that D. suzukii is amenable to transgenesis using the transposon-based vectors piggyBac and Minos, site-specific recombination (lox/Cre), and CRISPR/Cas9 genome editing. Results We experienced differences in the usability of piggyBac-based germline transformation in different strains of D. suzukii: we obtained no transgenic lines in a US strain, a single rare transgenic line in an Italian strain, but observed a reliable transformation rate of 2.5 to 11% in a strain from the French Alps. This difference in efficiency was confirmed by comparative examination of these three strains. In addition, we used an attP landing site line to successfully established φC31-integrase-mediated plasmid integration at a rate of 10% and generated landing site lines with two attP sequences to effectively perform φC31-Recombinase Mediated Cassette Exchange (φC31-RMCE) with 11% efficiency. Moreover, we isolated and used the endogenous regulatory regions of Ds nanos to express φC31 integrase maternally to generate self-docking lines for φC31-RMCE. Besides, we isolated the promoter/enhancer of Ds serendipity α to drive the heterologous tetracycline-controlled transactivator (tTA) during early embryonic development and generated a testes-specific tTA driver line using the endogenous beta-2-tubulin (β2t) promoter/enhancer. Conclusion Our results provide evidence that the D. suzukii strain AM derived from the French Alps is more suitable for piggyBac germline transformation than other strains. We demonstrated the feasibility of using φC31-RMCE in the cherry vinegar fly and generated a set of lines that can be used for highly efficient integration of larger constructs. The φC31-based integration will facilitate modification and stabilization of previously generated transgenic lines that carry at least one attP site in the transgene construction. An early embryo-specific and a spermatogenesis-specific driver line were generated for future use of the binary expression system tet-off to engineer tissue- and stage-specific effector gene expression for genetic pest control strategies. Supplementary Information The online version contains supplementary material available at 10.1186/s12863-020-00940-5.
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Affiliation(s)
- Hassan M M Ahmed
- Department of Developmental Biology, Johann-Friedrich-Blumenbach-Institute of Zoology and Anthropology, Göttingen Center for Molecular Biosciences, Georg-August-University Göttingen, 37077, Göttingen, Germany.,Department of Crop Protection, Faculty of Agriculture-University of Khartoum, P.O. Box 32, 13314, Khartoum North, Khartoum, Sudan
| | - Fabienne Heese
- Department of Developmental Biology, Johann-Friedrich-Blumenbach-Institute of Zoology and Anthropology, Göttingen Center for Molecular Biosciences, Georg-August-University Göttingen, 37077, Göttingen, Germany
| | - Ernst A Wimmer
- Department of Developmental Biology, Johann-Friedrich-Blumenbach-Institute of Zoology and Anthropology, Göttingen Center for Molecular Biosciences, Georg-August-University Göttingen, 37077, Göttingen, Germany.
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Guo C, Tsai SJ, Ai Y, Li M, Pekosz A, Cox A, Atai N, Gould SJ. The D614G Mutation Enhances the Lysosomal Trafficking of SARS-CoV-2 Spike. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2020. [PMID: 33330866 PMCID: PMC7743070 DOI: 10.1101/2020.12.08.417022] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The spike D614G mutation increases SARS-CoV-2 infectivity, viral load, and transmission but the molecular mechanism underlying these effects remains unclear. We report here that spike is trafficked to lysosomes and that the D614G mutation enhances the lysosomal sorting of spike and the lysosomal accumulation of spike-positive punctae in SARS-CoV-2-infected cells. Spike trafficking to lysosomes is an endocytosis-independent, V-ATPase-dependent process, and spike-containing lysosomes drive lysosome clustering but display poor lysotracker labeling and reduced uptake of endocytosed materials. These results are consistent with a lysosomal pathway of coronavirus biogenesis and raise the possibility that a common mechanism may underly the D614G mutation’s effects on spike protein trafficking in infected cells and the accelerated entry of SARS-CoV-2 into uninfected cells.
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Koehler C, Estrada Girona G, Reinkemeier CD, Lemke EA. Inducible Genetic Code Expansion in Eukaryotes. Chembiochem 2020; 21:3216-3219. [PMID: 32598534 PMCID: PMC7754456 DOI: 10.1002/cbic.202000338] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 06/25/2020] [Indexed: 11/07/2022]
Abstract
Genetic code expansion (GCE) is a versatile tool to site-specifically incorporate a noncanonical amino acid (ncAA) into a protein, for example, to perform fluorescent labeling inside living cells. To this end, an orthogonal aminoacyl-tRNA-synthetase/tRNA (RS/tRNA) pair is used to insert the ncAA in response to an amber stop codon in the protein of interest. One of the drawbacks of this system is that, in order to achieve maximum efficiency, high levels of the orthogonal tRNA are required, and this could interfere with host cell functionality. To minimize the adverse effects on the host, we have developed an inducible GCE system that enables us to switch on tRNA or RS expression when needed. In particular, we tested different promotors in the context of the T-REx or Tet-On systems to control expression of the desired orthogonal tRNA and/or RS. We discuss our result with respect to the control of GCE components as well as efficiency. We found that only the T-REx system enables simultaneous control of tRNA and RS expression.
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Affiliation(s)
- Christine Koehler
- BiocentreJohannes-Gutenberg University Mainz55128MainzGermany
- Institute of Molecular Biology gGmbH55128MainzGermany
- Structural and Computational Biology Unit and Cell Biology and Biophysics UnitEuropean Molecular Biology LaboratoryMeyerhofstraße 169117HeidelbergGermany
- ARAXA Biosciences GmbHMeyerhofstraße 169117HeidelbergGermany
| | - Gemma Estrada Girona
- Structural and Computational Biology Unit and Cell Biology and Biophysics UnitEuropean Molecular Biology LaboratoryMeyerhofstraße 169117HeidelbergGermany
| | - Christopher D. Reinkemeier
- BiocentreJohannes-Gutenberg University Mainz55128MainzGermany
- Institute of Molecular Biology gGmbH55128MainzGermany
- Structural and Computational Biology Unit and Cell Biology and Biophysics UnitEuropean Molecular Biology LaboratoryMeyerhofstraße 169117HeidelbergGermany
| | - Edward A. Lemke
- BiocentreJohannes-Gutenberg University Mainz55128MainzGermany
- Institute of Molecular Biology gGmbH55128MainzGermany
- Structural and Computational Biology Unit and Cell Biology and Biophysics UnitEuropean Molecular Biology LaboratoryMeyerhofstraße 169117HeidelbergGermany
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Li L, Meng H, Zhang J, Liu Y, Zou Q, Gao Y, Yang H, Lai L. A tunable, rapid, and precise drug control of protein expression by combining transcriptional and post-translational regulation systems. J Genet Genomics 2020; 47:705-712. [PMID: 33549479 DOI: 10.1016/j.jgg.2020.07.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 06/10/2020] [Accepted: 07/20/2020] [Indexed: 10/23/2022]
Abstract
Rapid, precise, and tunable regulation of protein abundance would be significantly useful in a variety of biotechnologies and biomedical applications. Here, we describe a system that allows tunable and rapid drug control of gene expression for either gene activation or inactivation in mammalian cells. We construct the system by coupling Tet-on 3G and small molecule-assisted shutoff systems, which can respectively induce transcriptional activation and protein degradation in the presence of corresponding small molecules. This dual-input drug inducer regulation system facilitates a bidirectional control of gene expression. The gene of interest can be precisely controlled by dual small molecules in a broad dynamic range of expression from overexpression to complete silence, allowing gene function study in a comprehensive expression profile. Our results reveal that the bidirectional control system enables sensitive dosage- and time-dependent regulation for either turn-on or shutoff of gene expression. We also apply this system for inducible genome editing and gene activation mediated by clustered regularly interspaced short palindromic repeats. The system provides an integrated platform for studying multiple biological processes by manipulating gene expression in a more flexible way.
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Affiliation(s)
- Li Li
- Department of Hepatobiliary Surgery II, Guangdong Provincial Research Center for Artificial Organ and Tissue Engineering, Institute of Regenerative Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China
| | - Hongyi Meng
- Department of Hepatobiliary Surgery II, Guangdong Provincial Research Center for Artificial Organ and Tissue Engineering, Institute of Regenerative Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China
| | - Jianmin Zhang
- Department of Hepatobiliary Surgery II, Guangdong Provincial Research Center for Artificial Organ and Tissue Engineering, Institute of Regenerative Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China
| | - Yang Liu
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
| | - Qingjian Zou
- School of Biotechnology and Health Sciences, Wuyi University, Jiangmen, 529020, China.
| | - Yi Gao
- Department of Hepatobiliary Surgery II, Guangdong Provincial Research Center for Artificial Organ and Tissue Engineering, Institute of Regenerative Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China.
| | - Huaqiang Yang
- College of Animal Science, South China Agricultural University, Guangzhou, 510642, China.
| | - Liangxue Lai
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China; School of Biotechnology and Health Sciences, Wuyi University, Jiangmen, 529020, China.
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Sanchis P, Fernández-Gayol O, Comes G, Aguilar K, Escrig A, Giralt M, Palmiter RD, Hidalgo J. A new mouse model to study restoration of interleukin-6 (IL-6) expression in a Cre-dependent manner: microglial IL-6 regulation of experimental autoimmune encephalomyelitis. J Neuroinflammation 2020; 17:304. [PMID: 33059703 PMCID: PMC7565836 DOI: 10.1186/s12974-020-01969-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 09/28/2020] [Indexed: 01/12/2023] Open
Abstract
Background Interleukin-6 (IL-6) is a pleiotropic cytokine that controls numerous physiological processes both in basal and neuroinflammatory conditions, including the inflammatory response to experimental autoimmune encephalomyelitis (EAE). IL-6 is produced by multiple peripheral and central cells, and until now, the putative roles of IL-6 from different cell types have been evaluated through conditional cell-specific IL-6 knockout mice. Nevertheless, these mice probably undergo compensatory responses of IL-6 from other cells, which makes it difficult to assess the role of each source of IL-6. Methods To give some insight into this problem, we have produced a novel mouse model: a conditional reversible IL-6 KO mouse (IL6-DIO-KO). By using double-inverted, open-reading-frame (DIO) technology, we created a mouse line with the loss of Il6 expression in all cells that can be restored by the action of Cre recombinase. Since microglia are one of the most important sources and targets of IL-6 into the central nervous system, we have recovered microglial Il6 expression in IL6-DIO-KO mice through breeding to Cx3cr1-CreER mice and subsequent injection of tamoxifen (TAM) when mice were 10–16 weeks old. Then, they were immunized with myelin oligodendrocyte glycoprotein 35-55 peptide (MOG35-55) 7 weeks after TAM treatment to induce EAE. Clinical symptoms and demyelination, CD3 infiltration, and gliosis in the spinal cord were evaluated. Results IL6-DIO-KO mice were resistant to EAE, validating the new model. Restoration of microglial Il6 was sufficient to develop a mild version of EAE-related clinical symptoms and neuropathology. Conclusions IL6-DIO-KO mouse is an excellent model to understand in detail the role of specific cellular sources of IL-6 within a recovery-of-function paradigm in EAE.
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Affiliation(s)
- Paula Sanchis
- Institute of Neurosciences and Department of Cellular Biology, Physiology and Immunology, Animal Physiology Unit, Faculty of Biosciences, Universitat Autònoma de Barcelona, 08193, Barcelona, Spain
| | - Olaya Fernández-Gayol
- Institute of Neurosciences and Department of Cellular Biology, Physiology and Immunology, Animal Physiology Unit, Faculty of Biosciences, Universitat Autònoma de Barcelona, 08193, Barcelona, Spain.,Current affiliation: Department of Pediatrics, Division of Molecular Genetics, Columbia University Irving Medical Center, New York, 10032, USA
| | - Gemma Comes
- Institute of Neurosciences and Department of Cellular Biology, Physiology and Immunology, Animal Physiology Unit, Faculty of Biosciences, Universitat Autònoma de Barcelona, 08193, Barcelona, Spain
| | - Kevin Aguilar
- Institute of Neurosciences and Department of Cellular Biology, Physiology and Immunology, Animal Physiology Unit, Faculty of Biosciences, Universitat Autònoma de Barcelona, 08193, Barcelona, Spain
| | - Anna Escrig
- Institute of Neurosciences and Department of Cellular Biology, Physiology and Immunology, Animal Physiology Unit, Faculty of Biosciences, Universitat Autònoma de Barcelona, 08193, Barcelona, Spain
| | - Mercedes Giralt
- Institute of Neurosciences and Department of Cellular Biology, Physiology and Immunology, Animal Physiology Unit, Faculty of Biosciences, Universitat Autònoma de Barcelona, 08193, Barcelona, Spain
| | - Richard D Palmiter
- Department of Biochemistry, Genome Sciences, and Howard Hughes Medical Institute, University of Washington, Seattle, WA, 98195, USA
| | - Juan Hidalgo
- Institute of Neurosciences and Department of Cellular Biology, Physiology and Immunology, Animal Physiology Unit, Faculty of Biosciences, Universitat Autònoma de Barcelona, 08193, Barcelona, Spain.
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Chu D, Nguyen A, Smith SS, Vavrušová Z, Schneider RA. Stable integration of an optimized inducible promoter system enables spatiotemporal control of gene expression throughout avian development. Biol Open 2020; 9:bio055343. [PMID: 32917762 PMCID: PMC7561481 DOI: 10.1242/bio.055343] [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: 07/24/2020] [Accepted: 08/27/2020] [Indexed: 01/18/2023] Open
Abstract
Precisely altering gene expression is critical for understanding molecular processes of embryogenesis. Although some tools exist for transgene misexpression in developing chick embryos, we have refined and advanced them by simplifying and optimizing constructs for spatiotemporal control. To maintain expression over the entire course of embryonic development we use an enhanced piggyBac transposon system that efficiently integrates sequences into the host genome. We also incorporate a DNA targeting sequence to direct plasmid translocation into the nucleus and a D4Z4 insulator sequence to prevent epigenetic silencing. We designed these constructs to minimize their size and maximize cellular uptake, and to simplify usage by placing all of the integrating sequences on a single plasmid. Following electroporation of stage HH8.5 embryos, our tetracycline-inducible promoter construct produces robust transgene expression in the presence of doxycycline at any point during embryonic development in ovo or in culture. Moreover, expression levels can be modulated by titrating doxycycline concentrations and spatial control can be achieved using beads or gels. Thus, we have generated a novel, sensitive, tunable, and stable inducible-promoter system for high-resolution gene manipulation in vivo.
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Affiliation(s)
- Daniel Chu
- Department of Orthopaedic Surgery, University of California at San Francisco, 513 Parnassus Avenue, S-1164, San Francisco, CA 94143-0514, USA
| | - An Nguyen
- Department of Orthopaedic Surgery, University of California at San Francisco, 513 Parnassus Avenue, S-1164, San Francisco, CA 94143-0514, USA
| | - Spenser S Smith
- Department of Orthopaedic Surgery, University of California at San Francisco, 513 Parnassus Avenue, S-1164, San Francisco, CA 94143-0514, USA
| | - Zuzana Vavrušová
- Department of Orthopaedic Surgery, University of California at San Francisco, 513 Parnassus Avenue, S-1164, San Francisco, CA 94143-0514, USA
| | - Richard A Schneider
- Department of Orthopaedic Surgery, University of California at San Francisco, 513 Parnassus Avenue, S-1164, San Francisco, CA 94143-0514, USA
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