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Nooti S, Naylor M, Long T, Groll B, Manu. LucFlow: A method to measure Luciferase reporter expression in single cells. PLoS One 2023; 18:e0292317. [PMID: 37792708 PMCID: PMC10550117 DOI: 10.1371/journal.pone.0292317] [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: 06/28/2023] [Accepted: 09/18/2023] [Indexed: 10/06/2023] Open
Abstract
Reporter assays, in which the expression of an inert protein is driven by gene regulatory elements such as promoters and enhancers, are a workhorse for investigating gene regulation. Techniques for measuring reporter gene expression vary from single-cell or single-molecule approaches having low throughput to bulk Luciferase assays that have high throughput. We developed a Luciferase Reporter Assay using Flow-Cytometry (LucFlow), which measures reporter expression in single cells immunostained for Luciferase. We optimized and tested LucFlow with a murine cell line that can be differentiated into neutrophils, into which promoter-reporter and enhancer-promoter-reporter constructs have been integrated in a site-specific manner. The single-cell measurements are comparable to bulk ones but we found that dead cells have no detectable Luciferase protein, so that bulk assays underestimate reporter expression. LucFlow is able to achieve a higher accuracy than bulk methods by excluding dead cells during flow cytometry. Prior to fixation and staining, the samples are spiked with stained cells that can be discriminated during flow cytometry and control for tube-to-tube variation in experimental conditions. Computing fold change relative to control cells allows LucFlow to achieve a high level of precision. LucFlow, therefore, enables the accurate and precise measurement of reporter expression in a high throughput manner.
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Affiliation(s)
- Sunil Nooti
- Department of Biology, University of North Dakota, Grand Forks, ND, United States of America
| | - Madison Naylor
- Department of Biology, University of North Dakota, Grand Forks, ND, United States of America
| | - Trevor Long
- Department of Biology, University of North Dakota, Grand Forks, ND, United States of America
| | - Brayden Groll
- Department of Biology, University of North Dakota, Grand Forks, ND, United States of America
| | - Manu
- Department of Biology, University of North Dakota, Grand Forks, ND, United States of America
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Wu C, Qavi AJ, Moyle AB, Wagner ND, Hachim A, Kavian N, Cole AR, Sweeney-Gibbons J, Rohrs HW, Peiris JM, Basler CF, Gross ML, Valkenburg SA, Farnsworth CW, Amarasinghe GK, Leung DW. Domain-specific biochemical and serological characterization of SARS-CoV-2 nucleocapsid protein. STAR Protoc 2021; 2:100906. [PMID: 34642671 PMCID: PMC8495048 DOI: 10.1016/j.xpro.2021.100906] [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] [Indexed: 11/29/2022] Open
Abstract
Nucleocapsid proteins are essential for SARS-CoV-2 life cycle. Here, we describe protocols to gather domain-specific insights about essential properties of nucleocapsids. These assays include dynamic light scattering to characterize oligomerization, fluorescence polarization to quantify RNA binding, hydrogen-deuterium exchange mass spectrometry to map RNA binding regions, negative-stain electron microscopy to visualize oligomeric species, interferon reporter assay to evaluate interferon signaling modulation, and a serology assay to reveal insights for improved sensitivity and specificity. These assays are broadly applicable to RNA-encapsidated nucleocapsids. For complete details on the use and execution of this protocol, please refer to Wu et al. (2021).
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Affiliation(s)
- Chao Wu
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
| | - Abraham J. Qavi
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
| | - Austin B. Moyle
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Nicole D. Wagner
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Asmaa Hachim
- HKU-Pasteur Research Pole, School of Public Health, The University of Hong Kong, Hong Kong, China
| | - Niloufar Kavian
- HKU-Pasteur Research Pole, School of Public Health, The University of Hong Kong, Hong Kong, China
- Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Assistance Publique–Hôpitaux de Paris, Hôpital Universitaire Paris Centre, Centre Hospitalier Universitaire Cochin, Service d’Immunologie Biologique, Paris, France
- Institut Cochin, INSERM U1016, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Aidan R. Cole
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
| | - Joyce Sweeney-Gibbons
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA
| | - Henry W. Rohrs
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - J.S. Malik Peiris
- HKU-Pasteur Research Pole, School of Public Health, The University of Hong Kong, Hong Kong, China
- Division of Public Health Laboratory Sciences, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Christopher F. Basler
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA
| | - Michael L. Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Sophie A. Valkenburg
- HKU-Pasteur Research Pole, School of Public Health, The University of Hong Kong, Hong Kong, China
| | - Christopher W. Farnsworth
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
| | - Gaya K. Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
| | - Daisy W. Leung
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
- Department of Internal Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
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Chong ZX, Yeap SK, Ho WY. Transfection types, methods and strategies: a technical review. PeerJ 2021; 9:e11165. [PMID: 33976969 PMCID: PMC8067914 DOI: 10.7717/peerj.11165] [Citation(s) in RCA: 92] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 03/05/2021] [Indexed: 12/17/2022] Open
Abstract
Transfection is a modern and powerful method used to insert foreign nucleic acids into eukaryotic cells. The ability to modify host cells' genetic content enables the broad application of this process in studying normal cellular processes, disease molecular mechanism and gene therapeutic effect. In this review, we summarized and compared the findings from various reported literature on the characteristics, strengths, and limitations of various transfection methods, type of transfected nucleic acids, transfection controls and approaches to assess transfection efficiency. With the vast choices of approaches available, we hope that this review will help researchers, especially those new to the field, in their decision making over the transfection protocol or strategy appropriate for their experimental aims.
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Affiliation(s)
- Zhi Xiong Chong
- School of Pharmacy, University of Nottingham Malaysia, Semenyih, Selangor, Malaysia
| | - Swee Keong Yeap
- China-ASEAN College of Marine Sciences, Xiamen University Malaysia, Sepang, Selangor, Malaysia
| | - Wan Yong Ho
- School of Pharmacy, University of Nottingham Malaysia, Semenyih, Selangor, Malaysia
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Oh S, Song H, Freeman WM, Shin S, Janknecht R. Cooperation between ETS transcription factor ETV1 and histone demethylase JMJD1A in colorectal cancer. Int J Oncol 2020; 57:1319-1332. [PMID: 33174020 PMCID: PMC7646594 DOI: 10.3892/ijo.2020.5133] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 10/05/2020] [Indexed: 12/18/2022] Open
Abstract
ETS variant 1 (ETV1) is an oncogenic transcription factor. However, its role in colorectal cancer has remained understudied. The present study demonstrated that ETV1 downregulation led to reduced HCT116 colorectal cancer cell growth and clonogenic activity. Furthermore, the ETV1 mRNA levels were enhanced in colorectal tumors and were associated with disease severity. In addition, ETV1 directly bound to Jumonji C domain-containing (JMJD) 1A, a histone demethylase known to promote colon cancer. ETV1 and JMJD1A, but not a catalytically inactive mutant thereof, cooperated in inducing the matrix metalloproteinase (MMP)1 gene promoter that was similar to the cooperation between ETV1 and another histone demethylase, JMJD2A. RNA-sequencing revealed multiple potential ETV1 target genes in HCT116 cells, including the FOXQ1 and TBX6 transcription factor genes. Moreover, JMJD1A co-regulated FOXQ1 and other ETV1 target genes, but not TBX6, whereas JMJD2A downregulation had no impact on FOXQ1 as well as TBX6 transcription. Accordingly, the FOXQ1 gene promoter was stimulated by ETV1 and JMJD1A in a cooperative manner, and both ETV1 and JMJD1A bound to the FOXQ1 promoter. Notably, the overexpression of FOXQ1 partially reversed the growth inhibitory effects of ETV1 ablation on HCT116 cells, whereas TBX6 impaired HCT116 cell growth and may thereby dampen the oncogenic activity of ETV1. The latter also revealed for the first time, to the best of our knowledge, a potential tumor suppressive function of TBX6. Taken together, the present study uncovered a ETV1/JMJD1A-FOXQ1 axis that may drive colorectal tumorigenesis.
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Affiliation(s)
- Sangphil Oh
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Hoogeun Song
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | | | - Sook Shin
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Ralf Janknecht
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
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