1
|
Utrilla-Trigo S, Jiménez-Cabello L, Marín-López A, Illescas-Amo M, Andrés G, Calvo-Pinilla E, Lorenzo G, van Rijn PA, Ortego J, Nogales A. Engineering recombinant replication-competent bluetongue viruses expressing reporter genes for in vitro and non-invasive in vivo studies. Microbiol Spectr 2024; 12:e0249323. [PMID: 38353566 PMCID: PMC10923215 DOI: 10.1128/spectrum.02493-23] [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: 06/14/2023] [Accepted: 12/22/2023] [Indexed: 03/06/2024] Open
Abstract
Bluetongue virus (BTV) is the causative agent of the important livestock disease bluetongue (BT), which is transmitted via Culicoides bites. BT causes severe economic losses associated with its considerable impact on health and trade of animals. By reverse genetics, we have designed and rescued reporter-expressing recombinant (r)BTV expressing NanoLuc luciferase (NLuc) or Venus fluorescent protein. To generate these viruses, we custom synthesized a modified viral segment 5 encoding NS1 protein with the reporter genes located downstream and linked by the Porcine teschovirus-1 (PTV-1) 2A autoproteolytic cleavage site. Therefore, fluorescent signal or luciferase activity is only detected after virus replication and expression of non-structural proteins. Fluorescence or luminescence signals were detected in cells infected with rBTV/Venus or rBTV/NLuc, respectively. Moreover, the marking of NS2 protein confirmed that reporter genes were only expressed in BTV-infected cells. Growth kinetics of rBTV/NLuc and rBTV/Venus in Vero cells showed replication rates similar to those of wild-type and rBTV. Infectivity studies of these recombinant viruses in IFNAR(-/-) mice showed a higher lethal dose for rBTV/NLuc and rBTV/Venus than for rBTV indicating that viruses expressing the reporter genes are attenuated in vivo. Interestingly, luciferase activity was detected in the plasma of viraemic mice infected with rBTV/NLuc. Furthermore, luciferase activity quantitatively correlated with RNAemia levels of infected mice throughout the infection. In addition, we have investigated the in vivo replication and dissemination of BTV in IFNAR (-/-) mice using BTV/NLuc and non-invasive in vivo imaging systems.IMPORTANCEThe use of replication-competent viruses that encode a traceable fluorescent or luciferase reporter protein has significantly contributed to the in vitro and in vivo study of viral infections and the development of novel therapeutic approaches. In this work, we have generated rBTV that express fluorescent or luminescence proteins to track BTV infection both in vitro and in vivo. Despite the availability of vaccines, BTV and other related orbivirus are still associated with a significant impact on animal health and have important economic consequences worldwide. Our studies may contribute to the advance in orbivirus research and pave the way for the rapid development of new treatments, including vaccines.
Collapse
Affiliation(s)
- Sergio Utrilla-Trigo
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Valdeolmos, Madrid, Spain
| | - Luis Jiménez-Cabello
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Valdeolmos, Madrid, Spain
| | - Alejandro Marín-López
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Miguel Illescas-Amo
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Valdeolmos, Madrid, Spain
| | - Germán Andrés
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Valdeolmos, Madrid, Spain
| | - Eva Calvo-Pinilla
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Valdeolmos, Madrid, Spain
| | - Gema Lorenzo
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Valdeolmos, Madrid, Spain
| | - Piet A. van Rijn
- Department of Virology, Wageningen Bioveterinary Research (WBVR), Lelystad, the Netherlands
- Department of Biochemistry, Centre for Human Metabolomics, North-West University, Potchefstroom, South Africa
| | - Javier Ortego
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Valdeolmos, Madrid, Spain
| | - Aitor Nogales
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Valdeolmos, Madrid, Spain
| |
Collapse
|
2
|
Fu Q, Yang X, Wang M, Zhu K, Wang Y, Song J. Activatable Probes for Ratiometric Imaging of Endogenous Biomarkers In Vivo. ACS NANO 2024; 18:3916-3968. [PMID: 38258800 DOI: 10.1021/acsnano.3c10659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Dynamic variations in the concentration and abnormal distribution of endogenous biomarkers are strongly associated with multiple physiological and pathological states. Therefore, it is crucial to design imaging systems capable of real-time detection of dynamic changes in biomarkers for the accurate diagnosis and effective treatment of diseases. Recently, ratiometric imaging has emerged as a widely used technique for sensing and imaging of biomarkers due to its advantage of circumventing the limitations inherent to conventional intensity-dependent signal readout methods while also providing built-in self-calibration for signal correction. Here, the recent progress of ratiometric probes and their applications in sensing and imaging of biomarkers are outlined. Ratiometric probes are classified according to their imaging mechanisms, and ratiometric photoacoustic imaging, ratiometric optical imaging including photoluminescence imaging and self-luminescence imaging, ratiometric magnetic resonance imaging, and dual-modal ratiometric imaging are discussed. The applications of ratiometric probes in the sensing and imaging of biomarkers such as pH, reactive oxygen species (ROS), reactive nitrogen species (RNS), glutathione (GSH), gas molecules, enzymes, metal ions, and hypoxia are discussed in detail. Additionally, this Review presents an overview of challenges faced in this field along with future research directions.
Collapse
Affiliation(s)
- Qinrui Fu
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, Shandong 266021, China
| | - Xiao Yang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, Shandong 266021, China
| | - Mengzhen Wang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, Shandong 266021, China
| | - Kang Zhu
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Yin Wang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, Shandong 266021, China
| | - Jibin Song
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| |
Collapse
|
3
|
Chiem K, Park JG, Morales Vasquez D, Plemper RK, Torrelles JB, Kobie JJ, Walter MR, Ye C, Martinez-Sobrido L. Monitoring SARS-CoV-2 Infection Using a Double Reporter-Expressing Virus. Microbiol Spectr 2022; 10:e0237922. [PMID: 35980204 PMCID: PMC9603146 DOI: 10.1128/spectrum.02379-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 08/02/2022] [Indexed: 01/04/2023] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the highly contagious agent responsible for the coronavirus disease 2019 (COVID-19) pandemic. An essential requirement for understanding SARS-CoV-2 biology and the impact of antiviral therapeutics is a robust method to detect the presence of the virus in infected cells or animal models. Despite the development and successful generation of recombinant (r)SARS-CoV-2-expressing fluorescent or luciferase reporter genes, knowledge acquired from their use in in vitro assays and/or in live animals is limited to the properties of the fluorescent or luciferase reporter genes. Herein, for the first time, we engineered a replication-competent rSARS-CoV-2 that expresses both fluorescent (mCherry) and luciferase (Nluc) reporter genes (rSARS-CoV-2/mCherry-Nluc) to overcome limitations associated with the use of a single reporter gene. In cultured cells, rSARS-CoV-2/mCherry-Nluc displayed similar viral fitness as rSARS-CoV-2 expressing single reporter fluorescent and luciferase genes (rSARS-CoV-2/mCherry and rSARS-CoV-2/Nluc, respectively) or wild-type (WT) rSARS-CoV-2, while maintaining comparable expression levels of both reporter genes. In vivo, rSARS-CoV-2/mCherry-Nluc has similar pathogenicity in K18 human angiotensin-converting enzyme 2 (hACE2) transgenic mice than rSARS-CoV-2 expressing individual reporter genes or WT rSARS-CoV-2. Importantly, rSARS-CoV-2/mCherry-Nluc facilitates the assessment of viral infection and transmission in golden Syrian hamsters using in vivo imaging systems (IVIS). Altogether, this study demonstrates the feasibility of using this novel bioreporter-expressing rSARS-CoV-2 for the study of SARS-CoV-2 in vitro and in vivo. IMPORTANCE Despite the availability of vaccines and antivirals, the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to ravage health care institutions worldwide. Previously, we generated replication-competent recombinant (r)SARS-CoV-2 expressing fluorescent or luciferase reporter proteins to track viral infection in vitro and/or in vivo. However, these rSARS-CoV-2 are restricted to express only a single fluorescent or a luciferase reporter gene, limiting or preventing their use in specific in vitro assays and/or in vivo studies. To overcome this limitation, we have engineered a rSARS-CoV-2 expressing both fluorescent (mCherry) and luciferase (Nluc) genes and demonstrated its feasibility to study the biology of SARS-CoV-2 in vitro and/or in vivo, including the identification and characterization of neutralizing antibodies and/or antivirals. Using rodent models, we visualized SARS-CoV-2 infection and transmission through in vivo imaging systems (IVIS).
Collapse
Affiliation(s)
- Kevin Chiem
- Texas Biomedical Research Institute, San Antonio, Texas, USA
| | - Jun-Gyu Park
- Texas Biomedical Research Institute, San Antonio, Texas, USA
| | | | - Richard K. Plemper
- Center for Translational Antiviral Research, Institute for Biomedical Sciences, Georgia State University, Atlanta, Georgia, USA
| | | | - James J. Kobie
- Department of Medicine, Division of Infectious Diseases, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Mark R. Walter
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Chengjin Ye
- Texas Biomedical Research Institute, San Antonio, Texas, USA
| | | |
Collapse
|
4
|
Dehkharghanian T, Hashemiaghdam A, Ashrafi G. Semiautomated analysis of an optical ATP indicator in neurons. NEUROPHOTONICS 2022; 9:041410. [PMID: 35769720 PMCID: PMC9234513 DOI: 10.1117/1.nph.9.4.041410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 06/03/2022] [Indexed: 05/15/2023]
Abstract
Significance: The firefly enzyme luciferase has been used in a wide range of biological assays, including bioluminescence imaging of adenosine triphosphate (ATP). The biosensor Syn-ATP utilizes subcellular targeting of luciferase to nerve terminals for optical measurement of ATP in this compartment. Manual analysis of Syn-ATP signals is challenging due to signal heterogeneity and cellular motion in long imaging sessions. Here, we have leveraged machine learning tools to develop a method for analysis of bioluminescence images. Aim: Our goal was to create a semiautomated pipeline for analysis of bioluminescence imaging to improve measurements of ATP content in nerve terminals. Approach: We developed an image analysis pipeline that applies machine learning toolkits to distinguish neurons from background signals and excludes neural cell bodies, while also incorporating user input. Results: Side-by-side comparison of manual and semiautomated image analysis demonstrated that the latter improves precision and accuracy of ATP measurements. Conclusions: Our method streamlines data analysis and reduces user-introduced bias, thus enhancing the reproducibility and reliability of quantitative ATP imaging in nerve terminals.
Collapse
Affiliation(s)
| | - Arsalan Hashemiaghdam
- Washington University School of Medicine in St. Louis, Needleman Center for Neurometabolism and Axonal Therapeutics, Department of Cell Biology and Physiology, Department of Genetics, St. Louis, Missouri, United States
| | - Ghazaleh Ashrafi
- Washington University School of Medicine in St. Louis, Needleman Center for Neurometabolism and Axonal Therapeutics, Department of Cell Biology and Physiology, Department of Genetics, St. Louis, Missouri, United States
- Address all correspondence to Ghazaleh Ashrafi,
| |
Collapse
|
5
|
A Novel In Vitro Method to Assess the Microbial Barrier Function of Tissue Adhesives Using Bioluminescence Imaging Technique. BIOMED RESEARCH INTERNATIONAL 2022; 2022:3483238. [PMID: 35047631 PMCID: PMC8763484 DOI: 10.1155/2022/3483238] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 12/14/2021] [Indexed: 11/17/2022]
Abstract
Background. Tissue glues can minimize treatment invasiveness, mitigate the risk of infection, and reduce surgery time; ergo, they have been developed and used in surgical procedures as wound closure devices beside sutures, staples, and metallic grafts. Regardless of their structure or function, tissue glues should show an acceptable microbial barrier function before being used in humans. This study proposes a novel in vitro method using Escherichia coli Lux and bioluminescence imaging technique to assess the microbial barrier function of tissue glues. Different volumes and concentrations of E. coli Lux were applied to precured or cured polyurethane-based tissue glue placed on agar plates. Plates were cultured for 1 h, 24 h, 48 h, and 72 h with bioluminescence signal measurement subsequently. Herein, protocol established a volume of 5 μL of a 1 : 100 dilution of E. coli Lux containing around 2 × 107 CFU/mL as optimal for testing polyurethane-based tissue glue. Measurement of OD600nm, determination of CFU/mL, and correlation with the bioluminescence measurement in p/s unit resulted in a good correlation between CFU/mL and p/s and demonstrated good reproducibility of our method. In addition, this in vitro method could show that the tested polyurethane-based tissue glue can provide a reasonable barrier against the microbial penetration and act as a bacterial barrier for up to 48 h with no penetration and up to 72 h with a low level of penetration through the material. Overall, we have established a novel, sensitive, and reproducible in vitro method using the bioluminescence imaging technique for testing the microbial barrier function of new tissue glues.
Collapse
|
6
|
Morales Vasquez D, Chiem K, Ye C, Martinez-Sobrido L. Bioluminescent and Fluorescent Reporter-Expressing Recombinant SARS-CoV-2. Methods Mol Biol 2022; 2524:235-248. [PMID: 35821476 DOI: 10.1007/978-1-0716-2453-1_18] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Reporter-expressing recombinant severe acute respiratory syndrome coronavirus 2 (rSARS-CoV-2) represents an excellent tool to understand the biology of and ease studying viral infections in vitro and in vivo. The broad range of applications of reporter-expressing recombinant viruses is due to the facilitated expression of fluorescence or bioluminescence readouts. In this chapter, we describe a detailed protocol on the generation of rSARS-CoV-2 expressing Venus, mCherry, and NLuc that represents a valid surrogate to track viral infections.
Collapse
Affiliation(s)
| | - Kevin Chiem
- Texas Biomedical Research Institute, San Antonio, TX, USA
| | - Chengjin Ye
- Texas Biomedical Research Institute, San Antonio, TX, USA
| | - Luis Martinez-Sobrido
- Texas Biomedical Research Institute, San Antonio, TX, USA.
- Department of Disease Prevention and Intervention, Texas Biomedical Research Institute, San Antonio, TX, USA.
| |
Collapse
|
7
|
Guan M, Garabedian MV, Leutenegger M, Schuster BS, Good MC, Hammer DA. Incorporation and Assembly of a Light-Emitting Enzymatic Reaction into Model Protein Condensates. Biochemistry 2021; 60:3137-3151. [PMID: 34648259 DOI: 10.1021/acs.biochem.1c00373] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Eukaryotic cells partition enzymes and other cellular components into distinct subcellular compartments to generate specialized biochemical niches. A subclass of these compartments form in the absence of lipid membranes, via liquid-liquid phase separation of proteins to form biomolecular condensates or "membraneless organelles" such as nucleoli, stress granules, and P-bodies. Because of their propensity to form compartments from simple starting materials, membraneless organelles are an attractive target for engineering new functionalities in both living cells and protocells. In this work, we demonstrate incorporation of a novel enzymatic activity in protein coacervates with the light-generating enzyme, NanoLuc, to produce bioluminescence. Using condensates comprised of the disordered RGG domain of Caenorhabditis elegans LAF-1, we functionalized condensates with enzymatic activity in vitro and show that enzyme localization to coacervates enhances assembly and activity of split enzymes. To build condensates that function as light-emitting reactors, we designed a NanoLuc enzyme flanked by RGG domains. The resulting condensates concentrated NanoLuc by 10-fold over bulk solution and displayed significantly increased reaction rates. We further show that condensate viscosity impacts light emission due to diffusion-limited behavior. Because our model condensates have low viscosities, we predict NanoLuc diffusion-limited behavior in most other condensates and thus propose the condensate-Nanoluc system as a potential strategy for high-throughput screening of condensate targeting drugs. By splitting the NanoLuc enzyme into its constituent components, we demonstrate that NanoLuc activity can be reconstituted via co-condensation. In addition, we demonstrate control of the spatial localization of the enzyme within condensates by targettng NanoLuc to the surface of in vitro condensates. Collectively, this work demonstrates that membraneless organelles can be endowed with localized enzymatic activity and that this activity can be spatially and temporally controlled via biochemical reconstitution and design of protein surfactants.
Collapse
Affiliation(s)
- Muyang Guan
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Mikael V Garabedian
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Marcel Leutenegger
- Max Planck Institute for Biophysical Chemistry, Department of NanoBiophotonics, Am Faßberg 11, 37077 Göttingen, Germany
| | - Benjamin S Schuster
- Department of Chemical and Biochemical Engineering, Rutgers University, New Brunswick, New Jersey 08854, United States
| | - Matthew C Good
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.,Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Daniel A Hammer
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.,Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| |
Collapse
|
8
|
KUMADA R, ORIOKA M, CITTERIO D, HIRUTA Y. Fluorescent and Bioluminescent Probes based on Precise Molecular Design. BUNSEKI KAGAKU 2021. [DOI: 10.2116/bunsekikagaku.70.601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Rei KUMADA
- Department of Applied Chemistry, Keio University
| | | | | | - Yuki HIRUTA
- Department of Applied Chemistry, Keio University
| |
Collapse
|
9
|
Visaggio D, Pirolo M, Frangipani E, Lucidi M, Sorrentino R, Mitidieri E, Ungaro F, Luraghi A, Peri F, Visca P. A Highly Sensitive Luminescent Biosensor for the Microvolumetric Detection of the Pseudomonas aeruginosa Siderophore Pyochelin. ACS Sens 2021; 6:3273-3283. [PMID: 34476940 PMCID: PMC8477383 DOI: 10.1021/acssensors.1c01023] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The pyochelin (PCH) siderophore produced by the pathogenic bacterium Pseudomonas aeruginosa is an important virulence factor, acting as a growth promoter during infection. While strong evidence exists for PCH production in vivo, PCH quantification in biological samples is problematic due to analytical complexity, requiring extraction from large volumes and time-consuming purification steps. Here, the construction of a bioluminescent whole cell-based biosensor, which allows rapid, sensitive, and single-step PCH quantification in biological samples, is reported. The biosensor was engineered by fusing the promoter of the PCH biosynthetic gene pchE to the luxCDABE operon, and the resulting construct was inserted into the chromosome of the ΔpvdAΔpchDΔfpvA siderophore-null P. aeruginosa mutant. A bioassay was setup in a 96-well microplate format, enabling the contemporary screening of several samples in a few hours. A linear response was observed for up to 40 nM PCH, with a lower detection limit of 1.64 ± 0.26 nM PCH. Different parameters were considered to calibrate the biosensor, and a detailed step-by-step operation protocol, including troubleshooting specific problems that can arise during sample preparation, was established to achieve rapid, sensitive, and specific PCH quantification in both P. aeruginosa culture supernatants and biological samples. The biosensor was implemented as a screening tool to detect PCH-producing P. aeruginosa strains on a solid medium.
Collapse
Affiliation(s)
- Daniela Visaggio
- Department of Science, Roma Tre University, Rome 00146, Italy
- Santa Lucia Fundation IRCCS, Rome 00179, Italy
| | - Mattia Pirolo
- Department of Science, Roma Tre University, Rome 00146, Italy
| | - Emanuela Frangipani
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino 61029, Italy
| | | | - Raffaella Sorrentino
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples 80138, Italy
| | - Emma Mitidieri
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples 80138, Italy
| | - Francesca Ungaro
- Department of Pharmacy, University of Naples Federico II, Naples 80131, Italy
| | - Andrea Luraghi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan 20126, Italy
| | - Francesco Peri
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan 20126, Italy
| | - Paolo Visca
- Department of Science, Roma Tre University, Rome 00146, Italy
- Santa Lucia Fundation IRCCS, Rome 00179, Italy
| |
Collapse
|
10
|
Engineering with NanoLuc: a playground for the development of bioluminescent protein switches and sensors. Biochem Soc Trans 2021; 48:2643-2655. [PMID: 33242085 DOI: 10.1042/bst20200440] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 10/21/2020] [Accepted: 10/26/2020] [Indexed: 12/11/2022]
Abstract
The small engineered luciferase NanoLuc has rapidly become a powerful tool in the fields of biochemistry, chemical biology, and cell biology due to its exceptional brightness and stability. The continuously expanding NanoLuc toolbox has been employed in applications ranging from biosensors to molecular and cellular imaging, and currently includes split complementation variants, engineering techniques for spectral tuning, and bioluminescence resonance energy transfer-based concepts. In this review, we provide an overview of state-of-the-art NanoLuc-based sensors and switches with a focus on the underlying protein engineering approaches. We discuss the advantages and disadvantages of various strategies with respect to sensor sensitivity, modularity, and dynamic range of the sensor and provide a perspective on future strategies and applications.
Collapse
|
11
|
Evans JA, Welsh DK, Davidson AJ. Collection of Mouse Brain Slices for Bioluminescence Imaging of Circadian Clock Networks. Methods Mol Biol 2021; 2130:287-294. [PMID: 33284452 DOI: 10.1007/978-1-0716-0381-9_21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
Circadian rhythms in cellular function can be monitored in real time with bioluminescence imaging. In this approach, bioluminescence is produced by an enzymatic reaction, which can be used to report dynamic changes in gene or protein expression in living cells. Bioluminescence imaging in circadian experiments typically uses an ex vivo slice preparation, with the most commonly studied structure being the master clock in the suprachiasmatic nucleus (SCN) of the anterior hypothalamus. Here we describe procedures for dissecting and collecting SCN slices for bioluminescence imaging experiments.
Collapse
Affiliation(s)
- Jennifer A Evans
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI, USA.
| | - David K Welsh
- Department of Psychiatry and Center for Circadian Biology, University of California San Diego, La Jolla, CA, USA.,Veterans Affairs San Diego Healthcare System, San Diego, CA, USA
| | - Alec J Davidson
- Department of Neurobiology, Morehouse School of Medicine, Atlanta, GA, USA
| |
Collapse
|
12
|
Iwado S, Abe S, Oshimura M, Kazuki Y, Nakajima Y. Bioluminescence Measurement of Time-Dependent Dynamic Changes of CYP-Mediated Cytotoxicity in CYP-Expressing Luminescent HepG2 Cells. Int J Mol Sci 2021; 22:ijms22062843. [PMID: 33799598 PMCID: PMC7999318 DOI: 10.3390/ijms22062843] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 03/05/2021] [Accepted: 03/08/2021] [Indexed: 12/26/2022] Open
Abstract
We sought to develop a cell-based cytotoxicity assay using human hepatocytes, which reflect the effects of drug-metabolizing enzymes on cytotoxicity. In this study, we generated luminescent human hepatoblastoma HepG2 cells using the mouse artificial chromosome vector, in which click beetle luciferase alone or luciferase and major drug-metabolizing enzymes (CYP2C9, CYP2C19, CYP2D6, and CYP3A4) are expressed, and monitored the time-dependent changes of CYP-mediated cytotoxicity expression by bioluminescence measurement. Real-time bioluminescence measurement revealed that compared with CYP-non-expressing cells, the luminescence intensity of CYP-expressing cells rapidly decreased when the cells were treated with low concentrations of aflatoxin B1 or primaquine, which exhibits cytotoxicity in the presence of CYP3A4 or CYP2D6, respectively. Using kinetics data obtained by the real-time bioluminescence measurement, we estimated the time-dependent changes of 50% inhibitory concentration (IC50) values in the aflatoxin B1- and primaquine-treated cell lines. The first IC50 value was detected much earlier and at a lower concentration in primaquine-treated CYP-expressing HepG2 cells than in primaquine-treated CYP-non-expressing cells, and the decrease of IC50 values was much faster in the former than the latter. Thus, we successfully monitored time- and concentration-dependent dynamic changes of CYP-mediated cytotoxicity expression in CYP-expressing luminescent HepG2 cells by means of real-time bioluminescence measurement.
Collapse
Affiliation(s)
- Satoru Iwado
- Chromosome Engineering Research Center, Tottori University, 86 Nishi-cho, Yonago 683-8503, Tottori, Japan; (S.I.); (S.A.); (M.O.)
| | - Satoshi Abe
- Chromosome Engineering Research Center, Tottori University, 86 Nishi-cho, Yonago 683-8503, Tottori, Japan; (S.I.); (S.A.); (M.O.)
| | - Mitsuo Oshimura
- Chromosome Engineering Research Center, Tottori University, 86 Nishi-cho, Yonago 683-8503, Tottori, Japan; (S.I.); (S.A.); (M.O.)
| | - Yasuhiro Kazuki
- Chromosome Engineering Research Center, Tottori University, 86 Nishi-cho, Yonago 683-8503, Tottori, Japan; (S.I.); (S.A.); (M.O.)
- Division of Genome and Cellular Functions, Department of Molecular and Cellular Biology, School of Life Science, Faculty of Medicine, Tottori University, 86 Nishi-cho, Yonago 683-8503, Tottori, Japan
- Correspondence: (Y.K.); (Y.N.); Tel.: +81-859-38-6219 (Y.K.); +81-87-869-3525 (Y.N.)
| | - Yoshihiro Nakajima
- Chromosome Engineering Research Center, Tottori University, 86 Nishi-cho, Yonago 683-8503, Tottori, Japan; (S.I.); (S.A.); (M.O.)
- Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2217-14 Hayashi-cho, Takamatsu 761-0395, Kagawa, Japan
- Correspondence: (Y.K.); (Y.N.); Tel.: +81-859-38-6219 (Y.K.); +81-87-869-3525 (Y.N.)
| |
Collapse
|
13
|
Abstract
The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the pathogen responsible of coronavirus disease 2019 (COVID-19), has devastated public health services and economies worldwide. Despite global efforts to contain the COVID-19 pandemic, SARS-CoV-2 is now found in over 200 countries and has caused an upward death toll of over 1 million human lives as of November 2020. To date, only one Food and Drug Administration (FDA)-approved therapeutic drug (Remdesivir) and a monoclonal antibody, MAb (Bamlanivimab) are available for the treatment of SARS-CoV-2. As with other viruses, studying SARS-CoV-2 requires the use of secondary approaches to detect the presence of the virus in infected cells. To overcome this limitation, we have generated replication-competent recombinant (r)SARS-CoV-2 expressing fluorescent (Venus or mCherry) or bioluminescent (Nluc) reporter genes. Vero E6 cells infected with reporter-expressing rSARS-CoV-2 can be easily detected via fluorescence or luciferase expression and display a good correlation between reporter gene expression and viral replication. Moreover, rSARS-CoV-2 expressing reporter genes have comparable plaque sizes and growth kinetics to those of wild-type virus, rSARS-CoV-2/WT. We used these reporter-expressing rSARS-CoV-2 to demonstrate their feasibility to identify neutralizing antibodies (NAbs) or antiviral drugs. Our results demonstrate that reporter-expressing rSARS-CoV-2 represent an excellent option to identify therapeutics for the treatment of SARS-CoV-2, where reporter gene expression can be used as valid surrogates to track viral infection. Moreover, the ability to manipulate the viral genome opens the feasibility of generating viruses expressing foreign genes for their use as vaccines for the treatment of SARS-CoV-2 infection.IMPORTANCE Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the pathogen that causes coronavirus disease 2019 (COVID-19), has significantly impacted the human health and economic status worldwide. There is an urgent need to identify effective prophylactics and therapeutics for the treatment of SARS-CoV-2 infection and associated COVID-19 disease. The use of fluorescent- or luciferase-expressing reporter expressing viruses has significantly advanced viral research. Here, we generated recombinant (r)SARS-CoV-2 expressing fluorescent (Venus and mCherry) or luciferase (Nluc) reporter genes and demonstrate that they represent an excellent option to track viral infections in vitro. Importantly, reporter-expressing rSARS-CoV-2 display similar growth kinetics and plaque phenotype that their wild-type counterpart (rSARS-CoV-2/WT), demonstrating their feasibility to identify drugs and/or neutralizing antibodies (NAbs) for the therapeutic treatment of SARS-CoV-2. Henceforth, these reporter-expressing rSARS-CoV-2 can be used to interrogate large libraries of compounds and/or monoclonal antibodies (MAb), in high-throughput screening settings, to identify those with therapeutic potential against SARS-CoV-2.
Collapse
|
14
|
Endo M, Ozawa T. Advanced Bioluminescence System for In Vivo Imaging with Brighter and Red-Shifted Light Emission. Int J Mol Sci 2020; 21:E6538. [PMID: 32906768 PMCID: PMC7555964 DOI: 10.3390/ijms21186538] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 09/03/2020] [Accepted: 09/04/2020] [Indexed: 01/04/2023] Open
Abstract
In vivo bioluminescence imaging (BLI), which is based on luminescence emitted by the luciferase-luciferin reaction, has enabled continuous monitoring of various biochemical processes in living animals. Bright luminescence with a high signal-to-background ratio, ideally red or near-infrared light as the emission maximum, is necessary for in vivo animal experiments. Various attempts have been undertaken to achieve this goal, including genetic engineering of luciferase, chemical modulation of luciferin, and utilization of bioluminescence resonance energy transfer (BRET). In this review, we overview a recent advance in the development of a bioluminescence system for in vivo BLI. We also specifically examine the improvement in bioluminescence intensity by mutagenic or chemical modulation on several beetle and marine luciferase bioluminescence systems. We further describe that intramolecular BRET enhances luminescence emission, with recent attempts for the development of red-shifted bioluminescence system, showing great potency in in vivo BLI. Perspectives for future improvement of bioluminescence systems are discussed.
Collapse
Affiliation(s)
| | - Takeaki Ozawa
- Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan;
| |
Collapse
|
15
|
Yaw AM, Duong TV, Nguyen D, Hoffmann HM. Circadian rhythms in the mouse reproductive axis during the estrous cycle and pregnancy. J Neurosci Res 2020; 99:294-308. [PMID: 32128870 DOI: 10.1002/jnr.24606] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 01/17/2020] [Accepted: 02/12/2020] [Indexed: 12/26/2022]
Abstract
Molecular and behavioral timekeeping is regulated by the circadian system which includes the brain's suprachiasmatic nucleus (SCN) that translates environmental light information into neuronal and endocrine signals aligning peripheral tissue rhythms to the time of day. Despite the critical role of circadian rhythms in fertility, it remains unexplored how circadian rhythms change within reproductive tissues during pregnancy. To determine how estrous cycle and pregnancy impact phase relationships of reproductive tissues, we used PER2::Luciferase (PER2::LUC) circadian reporter mice and determined the time of day of PER2::LUC peak (phase) in the SCN, pituitary, uterus, and ovary. The relationships between reproductive tissue PER2::LUC phases changed throughout the estrous cycle and late pregnancy and were accompanied by changes to PER2::LUC period in the SCN, uterus, and ovary. To determine if the phase relationship adaptations were driven by sex steroids, we asked if progesterone, a hormone involved in estrous cyclicity and pregnancy, could regulate Per2-luciferase expression. Using an in vitro transfection assay, we found that progesterone increased Per2-luciferase expression in immortalized SCN (SCN2.2) and arcuate nucleus (KTAR) cells. In addition, progesterone shortened PER2::LUC period in ex vivo uterine tissue recordings collected during pregnancy. As progesterone dramatically increases during pregnancy, we evaluated wheel-running patterns in PER2::LUC mice. We confirmed that activity levels decrease during pregnancy and found that activity onset was delayed. Although SCN, but not arcuate nucleus, PER2::LUC period changed during late pregnancy, onset of locomotor activity did not correlate with SCN or arcuate nucleus PER2::LUC period.
Collapse
Affiliation(s)
- Alexandra M Yaw
- Department of Animal Science and the Reproductive and Developmental Science Program, Michigan State University, East Lansing, MI, USA
| | - Thu V Duong
- Department of Animal Science and the Reproductive and Developmental Science Program, Michigan State University, East Lansing, MI, USA
| | - Duong Nguyen
- Department of Animal Science and the Reproductive and Developmental Science Program, Michigan State University, East Lansing, MI, USA
| | - Hanne M Hoffmann
- Department of Animal Science and the Reproductive and Developmental Science Program, Michigan State University, East Lansing, MI, USA
| |
Collapse
|
16
|
Reporter gene imaging and its role in imaging-based drug development. Drug Discov Today 2020; 25:582-592. [DOI: 10.1016/j.drudis.2019.12.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 11/20/2019] [Accepted: 12/31/2019] [Indexed: 01/21/2023]
|
17
|
Gaspar LS, Álvaro AR, Carmo‐Silva S, Mendes AF, Relógio A, Cavadas C. The importance of determining circadian parameters in pharmacological studies. Br J Pharmacol 2019; 176:2827-2847. [PMID: 31099023 PMCID: PMC6637036 DOI: 10.1111/bph.14712] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 03/26/2019] [Accepted: 04/01/2019] [Indexed: 12/25/2022] Open
Abstract
In mammals, most molecular and cellular processes show circadian changes, leading to daily variations in physiology and ultimately in behaviour. Such daily variations induce a temporal coordination of processes that is essential to ensure homeostasis and health. Thus, it is of no surprise that pharmacokinetics (PK) and pharmacodynamics (PD) of many drugs are also subject to circadian variations, profoundly affecting their efficacy and tolerability. Understanding how circadian rhythms influence drug PK, PD, and toxicity might significantly improve treatment efficacy and decrease related side effects. Therefore, it is essential to take circadian variations into account and to determine circadian parameters in pharmacological studies, especially when drugs have a short half-life or target rhythmic processes. This review provides an overview of the current knowledge on circadian rhythms and their relevance to the field of pharmacology. Methodologies to evaluate circadian rhythms in vitro, in rodent models and in humans, from experimental to computational approaches, are described and discussed. Lastly, we aim at alerting the scientific, medical, and regulatory communities to the relevance of the physiological time, as a key parameter to be considered when designing pharmacological studies. This will eventually lead to more successful preclinical and clinical trials and pave the way to a more personalized treatment to the benefit of the patients.
Collapse
Affiliation(s)
- Laetitia S. Gaspar
- CNC—Center for Neuroscience and Cell BiologyUniversity of CoimbraCoimbraPortugal
- Center for Innovation in Biomedicine and Biotechnology (CIBB)University of CoimbraCoimbraPortugal
- Institute for Interdisciplinary Research (IIIUC)University of CoimbraCoimbraPortugal
| | - Ana Rita Álvaro
- CNC—Center for Neuroscience and Cell BiologyUniversity of CoimbraCoimbraPortugal
- Center for Innovation in Biomedicine and Biotechnology (CIBB)University of CoimbraCoimbraPortugal
| | - Sara Carmo‐Silva
- CNC—Center for Neuroscience and Cell BiologyUniversity of CoimbraCoimbraPortugal
- Center for Innovation in Biomedicine and Biotechnology (CIBB)University of CoimbraCoimbraPortugal
| | - Alexandrina Ferreira Mendes
- CNC—Center for Neuroscience and Cell BiologyUniversity of CoimbraCoimbraPortugal
- Center for Innovation in Biomedicine and Biotechnology (CIBB)University of CoimbraCoimbraPortugal
- Faculty of PharmacyUniversity of CoimbraCoimbraPortugal
| | - Angela Relógio
- Institute for Theoretical BiologyCharité—Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt—Universität zu Berlin, and Berlin Institute of HealthBerlinGermany
- Medical Department of Hematology, Oncology, and Tumor Immunology, Molecular Cancer Research CenterCharité—Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt—Universität zu Berlin, and Berlin Institute of HealthBerlinGermany
| | - Cláudia Cavadas
- CNC—Center for Neuroscience and Cell BiologyUniversity of CoimbraCoimbraPortugal
- Center for Innovation in Biomedicine and Biotechnology (CIBB)University of CoimbraCoimbraPortugal
- Faculty of PharmacyUniversity of CoimbraCoimbraPortugal
| |
Collapse
|
18
|
A Novel Fluorescent and Bioluminescent Bireporter Influenza A Virus To Evaluate Viral Infections. J Virol 2019; 93:JVI.00032-19. [PMID: 30867298 DOI: 10.1128/jvi.00032-19] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 03/04/2019] [Indexed: 11/20/2022] Open
Abstract
Studying influenza A virus (IAV) requires the use of secondary approaches to detect the presence of virus in infected cells. To overcome this problem, we and others have generated recombinant IAV expressing fluorescent or luciferase reporter genes. These foreign reporter genes can be used as valid surrogates to track the presence of virus. However, the limited capacity for incorporating foreign sequences in the viral genome forced researchers to select a fluorescent or a luciferase reporter gene, depending on the type of study. To circumvent this limitation, we engineered a novel recombinant replication-competent bireporter IAV (BIRFLU) expressing both fluorescent and luciferase reporter genes. In cultured cells, BIRFLU displayed growth kinetics comparable to those of wild-type (WT) virus and was used to screen neutralizing antibodies or compounds with antiviral activity. The expression of two reporter genes allows monitoring of viral inhibition by fluorescence or bioluminescence, overcoming the limitations associated with the use of one reporter gene as a readout. In vivo, BIRFLU effectively infected mice, and both reporter genes were detected using in vivo imaging systems (IVIS). The ability to generate recombinant IAV harboring multiple foreign genes opens unique possibilities for studying virus-host interactions and for using IAV in high-throughput screenings (HTS) to identify novel antivirals that can be incorporated into the therapeutic armamentarium to control IAV infections. Moreover, the ability to genetically manipulate the viral genome to express two foreign genes offers the possibility of developing novel influenza vaccines and the feasibility for using recombinant IAV as vaccine vectors to treat other pathogen infections.IMPORTANCE Influenza A virus (IAV) causes a human respiratory disease that is associated with significant health and economic consequences. In recent years, the use of replication-competent IAV expressing an easily traceable fluorescent or luciferase reporter protein has significantly contributed to progress in influenza research. However, researchers have been forced to select a fluorescent or a luciferase reporter gene due to the restricted capacity of the influenza viral genome for including foreign sequences. To overcome this limitation, we generated, for the first time, a recombinant replication-competent bireporter IAV (BIRFLU) that stably expresses two reporter genes (one fluorescent and one luciferase) to track IAV infections in vitro and in vivo The combination of cutting-edge techniques from molecular biology, animal research, and imaging technologies brings researchers the unique opportunity to use this new generation of reporter-expressing IAV to study viral infection dynamics in both cultured cells and animal models of viral infection.
Collapse
|
19
|
Zeng Z, Huang B, Huang S, Zhang R, Yan S, Yu X, Shu Y, Zhao C, Lei J, Zhang W, Yang C, Wu K, Wu Y, An L, Ji X, Gong C, Yuan C, Zhang L, Liu W, Feng Y, Zhang B, Dai Z, Shen Y, Wang X, Luo W, Haydon RC, Luu HH, Zhou L, Reid RR, He TC, Wu X. The development of a sensitive fluorescent protein-based transcript reporter for high throughput screening of negative modulators of lncRNAs. Genes Dis 2018; 5:62-74. [PMID: 30159383 PMCID: PMC6110536 DOI: 10.1016/j.gendis.2018.02.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
While the human genome is pervasively transcribed, <2% of the human genome is transcribed into protein-coding mRNAs, leaving most of the transcripts as noncoding RNAs, such as microRNAs and long-noncoding RNAs (lncRNAs), which are critical components of epigenetic regulation. lncRNAs are emerging as critical regulators of gene expression and genomic stability. However, it remains largely unknown about how lncRNAs are regulated. Here, we develop a highly sensitive and dynamic reporter that allows us to identify and/or monitor negative modulators of lncRNA transcript levels in a high throughput fashion. Specifically, we engineer a fluorescent fusion protein by fusing three copies of the PEST destruction domain of mouse ornithine decarboxylase (MODC) to the C-terminal end of the codon-optimized bilirubin-inducible fluorescent protein, designated as dBiFP, and show that the dBiFP protein is highly destabilized, compared with the commonly-used eGFP protein. We further demonstrate that the dBiFP signal is effectively down-regulated when the dBiFP and mouse lncRNA H19 chimeric transcript is silenced by mouse H19-specific siRNAs. Therefore, our results strongly suggest that the dBiFP fusion protein may serve as a sensitive and dynamic transcript reporter to monitor the inhibition of lncRNAs by microRNAs, synthetic regulatory RNA molecules, RNA binding proteins, and/or small molecule inhibitors so that novel and efficacious inhibitors targeting the epigenetic circuit can be discovered to treat human diseases such as cancer and other chronic disorders.
Collapse
Affiliation(s)
- Zongyue Zeng
- Ministry of Education Key Laboratory of Diagnostic Medicine and School of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, China.,Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA
| | - Bo Huang
- Ministry of Education Key Laboratory of Diagnostic Medicine and School of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, China.,Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA.,Department of Clinical Laboratory Medicine, the Second Affiliated Hospital of Nanchang University, Nanchang 330031, China
| | - Shifeng Huang
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA.,Departments of Clinical Laboratory Medicine, General Surgery, Orthopedic Surgery, Nephrology, and Cardiology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Ruyi Zhang
- Ministry of Education Key Laboratory of Diagnostic Medicine and School of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, China.,Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA
| | - Shujuan Yan
- Ministry of Education Key Laboratory of Diagnostic Medicine and School of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, China.,Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA
| | - Xinyi Yu
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA.,Departments of Clinical Laboratory Medicine, General Surgery, Orthopedic Surgery, Nephrology, and Cardiology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Yi Shu
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA.,The Children's Hospital, Chongqing Medical University, Chongqing 400014, China
| | - Chen Zhao
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA.,Departments of Clinical Laboratory Medicine, General Surgery, Orthopedic Surgery, Nephrology, and Cardiology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Jiayan Lei
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA.,Departments of Clinical Laboratory Medicine, General Surgery, Orthopedic Surgery, Nephrology, and Cardiology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Wenwen Zhang
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA.,Department of Laboratory Medicine and Clinical Diagnostics, the Affiliated Yantai Hospital, Binzhou Medical University, Yantai 264100, China
| | - Chao Yang
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA.,The Children's Hospital, Chongqing Medical University, Chongqing 400014, China
| | - Ke Wu
- Ministry of Education Key Laboratory of Diagnostic Medicine and School of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, China.,Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA
| | - Ying Wu
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA.,Department of Immunology and Microbiology, Beijing University of Chinese Medicine, Beijing 100029, China
| | - Liping An
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA.,Key Laboratory of Orthopaedic Surgery of Gansu Province and the Department of Orthopaedic Surgery, the Second Hospital of Lanzhou University, Lanzhou, 730030, China
| | - Xiaojuan Ji
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA.,The Children's Hospital, Chongqing Medical University, Chongqing 400014, China
| | - Cheng Gong
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA.,Department of Surgery, the Affiliated Zhongnan Hospital of Wuhan University, Wuhan 430071, China
| | - Chengfu Yuan
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA.,Department of Biochemistry and Molecular Biology, China Three Gorges University School of Medicine, Yichang 443002, China
| | - Linghuan Zhang
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA.,The Children's Hospital, Chongqing Medical University, Chongqing 400014, China
| | - Wei Liu
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA.,Departments of Clinical Laboratory Medicine, General Surgery, Orthopedic Surgery, Nephrology, and Cardiology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Yixiao Feng
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA.,Departments of Clinical Laboratory Medicine, General Surgery, Orthopedic Surgery, Nephrology, and Cardiology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Bo Zhang
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA.,Key Laboratory of Orthopaedic Surgery of Gansu Province and the Department of Orthopaedic Surgery, the Second Hospital of Lanzhou University, Lanzhou, 730030, China
| | - Zhengyu Dai
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA.,Department of Orthopaedic Surgery, Chongqing Hospital of Traditional Chinese Medicine, Chongqing 400021, China
| | - Yi Shen
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA.,Department of Orthopaedic Surgery, Xiangya Second Hospital of Central South University, Changsha 410011, China
| | - Xi Wang
- Ministry of Education Key Laboratory of Diagnostic Medicine and School of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, China.,Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA
| | - Wenping Luo
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA.,Chongqing Key Laboratory for Oral Diseases and Biomedical Sciences, and the Affiliated Hospital of Stomatology of Chongqing Medical University, Chongqing 401147, China
| | - Rex C Haydon
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA.,Departments of Clinical Laboratory Medicine, General Surgery, Orthopedic Surgery, Nephrology, and Cardiology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Hue H Luu
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA.,Departments of Clinical Laboratory Medicine, General Surgery, Orthopedic Surgery, Nephrology, and Cardiology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Lan Zhou
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA.,Departments of Clinical Laboratory Medicine, General Surgery, Orthopedic Surgery, Nephrology, and Cardiology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Russell R Reid
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA.,Department of Surgery, Laboratory of Craniofacial Biology and Development, Section of Plastic Surgery, The University of Chicago Medical Center, Chicago, IL 60637, USA
| | - Tong-Chuan He
- Ministry of Education Key Laboratory of Diagnostic Medicine and School of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, China.,Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA
| | - Xingye Wu
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA.,Departments of Clinical Laboratory Medicine, General Surgery, Orthopedic Surgery, Nephrology, and Cardiology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| |
Collapse
|
20
|
Strongly enhanced bacterial bioluminescence with the ilux operon for single-cell imaging. Proc Natl Acad Sci U S A 2018; 115:962-967. [PMID: 29339494 PMCID: PMC5798359 DOI: 10.1073/pnas.1715946115] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The emission of light generated in a process referred to as bioluminescence can be used for imaging of living cells over long timespans without phototoxicity or bleaching. The amounts of light produced in the bioluminescence process are very low, and exogenous substrate molecules are often required. We improved the brightness of bacterial bioluminescence, a system that features the advantage that all of the required molecular components are genetically encoded within a single operon. Consequently, we have engineered an improved operon ilux, which enables long-term visualization of single bacterial cells while simultaneously providing information about cellular viability. Bioluminescence imaging of single cells is often complicated by the requirement of exogenous luciferins that can be poorly cell-permeable or produce high background signal. Bacterial bioluminescence is unique in that it uses reduced flavin mononucleotide as a luciferin, which is abundant in all cells, making this system purely genetically encodable by the lux operon. Unfortunately, the use of bacterial bioluminescence has been limited by its low brightness compared with other luciferases. Here, we report the generation of an improved lux operon named ilux with an approximately sevenfold increased brightness when expressed in Escherichia coli; ilux can be used to image single E. coli cells with enhanced spatiotemporal resolution over several days. In addition, since only metabolically active cells produce bioluminescent signal, we show that ilux can be used to observe the effect of different antibiotics on cell viability on the single-cell level.
Collapse
|
21
|
Studying Nonsense-Mediated mRNA Decay in Mammalian Cells Using a Multicolored Bioluminescence-Based Reporter System. Methods Mol Biol 2018; 1720:213-224. [PMID: 29236262 DOI: 10.1007/978-1-4939-7540-2_16] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The nonsense-mediated mRNA decay (NMD) pathway degrades aberrant transcripts containing premature translation termination codons (PTCs) and also regulates the levels of many normal mRNAs containing NMD-inducing features. The activity of this pathway varies considerably in different cell types and can change in response to developmental and environmental cues. Modulating NMD activity represents a potential therapeutic avenue for certain genetic disorders and cancers. Simple reporter systems capable of faithfully assessing NMD activity in mammalian cells greatly facilitate both basic and translational research on NMD. Here we describe a simple and effective method for assaying NMD specifically and quickly in live mammalian cells using a multicolored bioluminescence-based reporter system. This reporter can be transiently or stably introduced into cultured cells as well as animals, and NMD activity can be accurately assessed by bioluminescence imaging, western blot, or RT-qPCR.
Collapse
|
22
|
Calcium Circadian Rhythmicity in the Suprachiasmatic Nucleus: Cell Autonomy and Network Modulation. eNeuro 2017; 4:eN-NWR-0160-17. [PMID: 28828400 PMCID: PMC5562299 DOI: 10.1523/eneuro.0160-17.2017] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 07/26/2017] [Indexed: 11/25/2022] Open
Abstract
Circadian rhythms of mammalian physiology and behavior are coordinated by the suprachiasmatic nucleus (SCN) in the hypothalamus. Within SCN neurons, various aspects of cell physiology exhibit circadian oscillations, including circadian clock gene expression, levels of intracellular Ca2+ ([Ca2+]i), and neuronal firing rate. [Ca2+]i oscillates in SCN neurons even in the absence of neuronal firing. To determine the causal relationship between circadian clock gene expression and [Ca2+]i rhythms in the SCN, as well as the SCN neuronal network dependence of [Ca2+]i rhythms, we introduced GCaMP3, a genetically encoded fluorescent Ca2+ indicator, into SCN neurons from PER2::LUC knock-in reporter mice. Then, PER2 and [Ca2+]i were imaged in SCN dispersed and organotypic slice cultures. In dispersed cells, PER2 and [Ca2+]i both exhibited cell autonomous circadian rhythms, but [Ca2+]i rhythms were typically weaker than PER2 rhythms. This result matches the predictions of a detailed mathematical model in which clock gene rhythms drive [Ca2+]i rhythms. As predicted by the model, PER2 and [Ca2+]i rhythms were both stronger in SCN slices than in dispersed cells and were weakened by blocking neuronal firing in slices but not in dispersed cells. The phase relationship between [Ca2+]i and PER2 rhythms was more variable in cells within slices than in dispersed cells. Both PER2 and [Ca2+]i rhythms were abolished in SCN cells deficient in the essential clock gene Bmal1. These results suggest that the circadian rhythm of [Ca2+]i in SCN neurons is cell autonomous and dependent on clock gene rhythms, but reinforced and modulated by a synchronized SCN neuronal network.
Collapse
|
23
|
Diemer T, Landgraf D, Noguchi T, Pan H, Moreno JL, Welsh DK. Cellular circadian oscillators in the suprachiasmatic nucleus remain coupled in the absence of connexin-36. Neuroscience 2017; 357:1-11. [PMID: 28576728 PMCID: PMC5556374 DOI: 10.1016/j.neuroscience.2017.05.037] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 05/18/2017] [Accepted: 05/22/2017] [Indexed: 11/26/2022]
Abstract
In mammals, the master circadian clock resides in the suprachiasmatic nucleus (SCN). The SCN is characterized by robust circadian oscillations of clock gene expression and neuronal firing. The synchronization of circadian oscillations among individual cells in the SCN is attributed to intercellular coupling. Previous studies have shown that gap junctions, specifically those composed of connexin-36 (Cx36) subunits, are required for coupling of electrical firing among SCN neurons at a time scale of milliseconds. However, it remains unknown whether Cx36 gap junctions also contribute to coupling of circadian (∼24h) rhythms of clock gene expression. Here, we investigated circadian expression patterns of the clock gene Period 2 (Per2) in the SCN of Cx36-deficient mice using luminometry and single-cell bioluminescence imaging. Surprisingly, we found that synchronization of circadian PER2 expression rhythms is maintained in SCN explants from Cx36-deficient mice. Since Cx36 expression levels change with age, we also tested circadian running-wheel behavior of juvenile (3-4weeks old) and adult (9-30weeks old) Cx36-deficient mice. We found that impact of connexin-36 expression on circadian behavior changes greatly during postnatal development. However, consistent with the intact synchrony among SCN cells in cultured explants, Cx36-deficient mice had intact locomotor circadian rhythms, although adults displayed a lengthened period in constant darkness. Our data indicate that even though Cx36 may be required for electrical coupling of SCN cells, it does not affect coupling of molecular clock gene rhythms. Thus, electrical coupling of neurons and coupling of circadian clock gene oscillations can be regulated independently in the SCN.
Collapse
Affiliation(s)
- Tanja Diemer
- Department of Psychiatry and Center for Circadian Biology, University of California, San Diego, La Jolla, CA, United States
| | - Dominic Landgraf
- Department of Psychiatry and Center for Circadian Biology, University of California, San Diego, La Jolla, CA, United States; Veterans Affairs San Diego Healthcare System, San Diego, CA, United States.
| | - Takako Noguchi
- Department of Psychiatry and Center for Circadian Biology, University of California, San Diego, La Jolla, CA, United States
| | - Haiyun Pan
- Department of Psychiatry and Center for Circadian Biology, University of California, San Diego, La Jolla, CA, United States
| | - Jose L Moreno
- Department of Psychiatry and Center for Circadian Biology, University of California, San Diego, La Jolla, CA, United States
| | - David K Welsh
- Department of Psychiatry and Center for Circadian Biology, University of California, San Diego, La Jolla, CA, United States; Veterans Affairs San Diego Healthcare System, San Diego, CA, United States
| |
Collapse
|
24
|
Kim TJ, Türkcan S, Pratx G. Modular low-light microscope for imaging cellular bioluminescence and radioluminescence. Nat Protoc 2017; 12:1055-1076. [PMID: 28426025 DOI: 10.1038/nprot.2017.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Low-light microscopy methods are receiving increased attention as new applications have emerged. One such application is to allow longitudinal imaging of light-sensitive cells with no phototoxicity and no photobleaching of fluorescent biomarkers. Another application is for imaging signals that are inherently dim and undetectable using standard microscopy techniques, such as bioluminescence, chemiluminescence or radioluminescence. In this protocol, we provide instructions on how to build a modular low-light microscope (1-4 d) by coupling two microscope objective lenses, back to back from each other, using standard optomechanical components. We also provide directions on how to image dim signals such as those of radioluminescence (1-1.5 h), bioluminescence (∼30 min) and low-excitation fluorescence (∼15 min). In particular, radioluminescence microscopy is explained in detail, as it is a newly developed technique that enables the study of small-molecule transport (e.g., radiolabeled drugs, metabolic precursors and nuclear medicine contrast agents) by single cells without perturbing endogenous biochemical processes. In this imaging technique, a scintillator crystal (e.g., CdWO4) is placed in close proximity to the radiolabeled cells, where it converts the radioactive decays into optical flashes detectable using a sensitive camera. Using the image reconstruction toolkit provided in this protocol, the flashes can be reconstructed to yield high-resolution images of the radiotracer distribution. With appropriate timing, the three aforementioned imaging modalities may be performed together on a population of live cells, allowing the user to perform parallel functional studies of cell heterogeneity at the single-cell level.
Collapse
Affiliation(s)
- Tae Jin Kim
- Department of Radiation Oncology, Division of Medical Physics, Stanford University School of Medicine, Palo Alto, California, USA
| | - Silvan Türkcan
- Department of Radiation Oncology, Division of Medical Physics, Stanford University School of Medicine, Palo Alto, California, USA
| | - Guillem Pratx
- Department of Radiation Oncology, Division of Medical Physics, Stanford University School of Medicine, Palo Alto, California, USA
| |
Collapse
|
25
|
Kato M, Sugiyama T, Sakai K, Yamashita T, Fujita H, Sato K, Tomonari S, Shichida Y, Ohuchi H. Two Opsin 3-Related Proteins in the Chicken Retina and Brain: A TMT-Type Opsin 3 Is a Blue-Light Sensor in Retinal Horizontal Cells, Hypothalamus, and Cerebellum. PLoS One 2016; 11:e0163925. [PMID: 27861495 PMCID: PMC5115664 DOI: 10.1371/journal.pone.0163925] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 09/17/2016] [Indexed: 01/15/2023] Open
Abstract
Opsin family genes encode G protein-coupled seven-transmembrane proteins that bind a retinaldehyde chromophore in photoreception. Here, we sought potential as yet undescribed avian retinal photoreceptors, focusing on Opsin 3 homologs in the chicken. We found two Opsin 3-related genes in the chicken genome: one corresponding to encephalopsin/panopsin (Opn3) in mammals, and the other belonging to the teleost multiple tissue opsin (TMT) 2 group. Bioluminescence imaging and G protein activation assays demonstrated that the chicken TMT opsin (cTMT) functions as a blue light sensor when forced-expressed in mammalian cultured cells. We did not detect evidence of light sensitivity for the chicken Opn3 (cOpn3). In situ hybridization demonstrated expression of cTMT in subsets of differentiating cells in the inner retina and, as development progressed, predominant localization to retinal horizontal cells (HCs). Immunohistochemistry (IHC) revealed cTMT in HCs as well as in small numbers of cells in the ganglion and inner nuclear layers of the post-hatch chicken retina. In contrast, cOpn3-IR cells were found in distinct subsets of cells in the inner nuclear layer. cTMT-IR cells were also found in subsets of cells in the hypothalamus. Finally, we found differential distribution of cOpn3 and cTMT proteins in specific cells of the cerebellum. The present results suggest that a novel TMT-type opsin 3 may function as a photoreceptor in the chicken retina and brain.
Collapse
Affiliation(s)
- Mutsuko Kato
- Department of Cytology and Histology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | | | - Kazumi Sakai
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Takahiro Yamashita
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Hirofumi Fujita
- Department of Cytology and Histology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Keita Sato
- Department of Cytology and Histology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Sayuri Tomonari
- Department of Life Systems, Institute of Technology and Science, Tokushima University Graduate School, Tokushima, Japan
| | - Yoshinori Shichida
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Hideyo Ohuchi
- Department of Cytology and Histology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
- * E-mail:
| |
Collapse
|
26
|
Abstract
![]()
Genetically encoded
FRET-based sensor proteins have significantly
contributed to our current understanding of the intracellular functions
of Zn2+. However, the external excitation required for
these fluorescent sensors can give rise to photobleaching and phototoxicity
during long-term imaging, limits applications that suffer from autofluorescence
and light scattering, and is not compatible with light-sensitive cells.
For these applications, sensor proteins based on Bioluminescence Resonance
Energy Transfer (BRET) would provide an attractive alternative. In
this work, we used the bright and stable luciferase NanoLuc to create
the first genetically encoded BRET sensors for measuring intracellular
Zn2+. Using a new sensor approach, the NanoLuc domain was
fused to the Cerulean donor domain of two previously developed FRET
sensors, eCALWY and eZinCh-2. In addition to preserving the excellent
Zn2+ affinity and specificity of their predecessors, these
newly developed sensors enable both BRET- and FRET-based detection.
While the dynamic range of the BRET signal for the eCALWY-based BLCALWY-1
sensor was limited by the presence of two competing BRET pathways,
BRET/FRET sensors based on the eZinCh-2 scaffold (BLZinCh-1 and -2)
yielded robust 25–30% changes in BRET ratio. In addition, introduction
of a chromophore-silencing mutation resulted in a BRET-only sensor
(BLZinCh-3) with increased BRET response (50%) and an unexpected 10-fold
increase in Zn2+ affinity. The combination of robust ratiometric
response, physiologically relevant Zn2+ affinities, and
stable and bright luminescence signal offered by the BLZinCh sensors
allowed monitoring of intracellular Zn2+ in plate-based
assays as well as intracellular BRET-based imaging in single living
cells in real time.
Collapse
Affiliation(s)
- Stijn J. A. Aper
- Laboratory
of Chemical Biology and Institute for Complex Molecular Systems (ICMS),
Department of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Pieterjan Dierickx
- Hubrecht Institute-KNAW and University Medical Center Utrecht, Utrecht, The Netherlands
- Division
of Heart and Lungs, Department of Cardiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Maarten Merkx
- Laboratory
of Chemical Biology and Institute for Complex Molecular Systems (ICMS),
Department of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| |
Collapse
|
27
|
Breen M, Nogales A, Baker SF, Martínez-Sobrido L. Replication-Competent Influenza A Viruses Expressing Reporter Genes. Viruses 2016; 8:v8070179. [PMID: 27347991 PMCID: PMC4974514 DOI: 10.3390/v8070179] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2016] [Revised: 06/16/2016] [Accepted: 06/19/2016] [Indexed: 12/12/2022] Open
Abstract
Influenza A viruses (IAV) cause annual seasonal human respiratory disease epidemics. In addition, IAV have been implicated in occasional pandemics with inordinate health and economic consequences. Studying IAV, in vitro or in vivo, requires the use of laborious secondary methodologies to identify virus-infected cells. To circumvent this requirement, replication-competent IAV expressing an easily traceable reporter protein can be used. Here we discuss the development and applications of recombinant replication-competent IAV harboring diverse fluorescent or bioluminescent reporter genes in different locations of the viral genome. These viruses have been employed for in vitro and in vivo studies, such as the screening of neutralizing antibodies or antiviral compounds, the identification of host factors involved in viral replication, cell tropism, the development of vaccines, or the assessment of viral infection dynamics. In summary, reporter-expressing, replicating-competent IAV represent a powerful tool for the study of IAV both in vitro and in vivo.
Collapse
Affiliation(s)
- Michael Breen
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642, USA.
| | - Aitor Nogales
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642, USA.
| | - Steven F Baker
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642, USA.
| | - Luis Martínez-Sobrido
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642, USA.
| |
Collapse
|
28
|
Abstract
Resonance Energy Transfer (RET)-based technologies are used to report protein-protein interactions in living cells. Among them, Bioluminescence-initiated RET (BRET) provides excellent sensitivity but the low light intensity intrinsic to the bioluminescent process hampers its use for the localization of protein complexes at the sub-cellular level. Herein we have characterized the methodological conditions required to reliably perform single-cell BRET imaging using an extremely bright luciferase, Nanoluciferase (Nluc). With this, we achieved an unprecedented performance in the field of protein-protein interaction imaging in terms of temporal and spatial resolution, duration of signal stability, signal sensitivity and dynamic range. As proof-of-principle, an Nluc-containing BRET-based sensor of ERK activity enabled the detection of subtle, transient and localized variations in ERK activity in neuronal dendritic spines, induced by the activation of endogenous synaptic NMDA receptors. This development will improve our comprehension of both the spatio-temporal dynamics of protein-protein interactions and the activation patterns of specific signaling pathways.
Collapse
|
29
|
Landgraf D, Wang LL, Diemer T, Welsh DK. NPAS2 Compensates for Loss of CLOCK in Peripheral Circadian Oscillators. PLoS Genet 2016; 12:e1005882. [PMID: 26895328 PMCID: PMC4760943 DOI: 10.1371/journal.pgen.1005882] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 01/28/2016] [Indexed: 12/19/2022] Open
Abstract
Heterodimers of CLOCK and BMAL1 are the major transcriptional activators of the mammalian circadian clock. Because the paralog NPAS2 can substitute for CLOCK in the suprachiasmatic nucleus (SCN), the master circadian pacemaker, CLOCK-deficient mice maintain circadian rhythms in behavior and in tissues in vivo. However, when isolated from the SCN, CLOCK-deficient peripheral tissues are reportedly arrhythmic, suggesting a fundamental difference in circadian clock function between SCN and peripheral tissues. Surprisingly, however, using luminometry and single-cell bioluminescence imaging of PER2 expression, we now find that CLOCK-deficient dispersed SCN neurons and peripheral cells exhibit similarly stable, autonomous circadian rhythms in vitro. In CLOCK-deficient fibroblasts, knockdown of Npas2 leads to arrhythmicity, suggesting that NPAS2 can compensate for loss of CLOCK in peripheral cells as well as in SCN. Our data overturn the notion of an SCN-specific role for NPAS2 in the molecular circadian clock, and instead indicate that, at the cellular level, the core loops of SCN neuron and peripheral cell circadian clocks are fundamentally similar. In mammals, circadian clocks are based on a core transcriptional–translational feedback loop. BMAL1 and CLOCK activate the transcription of Per1-3 and Cry1/2. PER and CRY proteins inhibit BMAL1/CLOCK, and thus their own transcription. In Clock-/- mice, NPAS2 can substitute for CLOCK in the suprachiasmatic nucleus (SCN), the major circadian pacemaker. However, peripheral tissues of Clock-/- mice were reported to lack circadian rhythms. Since then, the protein CLOCK has been deemed essential for circadian rhythms in peripheral tissues. However, here we show that Clock-/- peripheral cells and tissues exhibit stable, autonomous circadian rhythms. Furthermore, in Clock-/- fibroblasts, knockdown of Npas2 leads to arrhythmicity, suggesting that NPAS2 can compensate for the loss of CLOCK in peripheral cells as well as in SCN. Our data overturn the notion of an SCN-specific role for NPAS2, and instead indicate that the core loops of SCN neuron and peripheral cell circadian clocks are fundamentally similar. This finding redefines a basic principle of molecular circadian clock regulation in peripheral organs which are essential for many metabolic processes. Disturbances of these rhythms lead to disorders like diabetes, obesity, and cancer. Thus, understanding the molecular basis of peripheral circadian oscillators is essential to develop treatments against clock-related disorders.
Collapse
Affiliation(s)
- Dominic Landgraf
- Veterans Affairs San Diego Healthcare System, San Diego, California, United States of America
- Department of Psychiatry & Center for Circadian Biology, University of California, San Diego, La Jolla, California, United States of America
- * E-mail:
| | - Lexie L. Wang
- Department of Psychiatry & Center for Circadian Biology, University of California, San Diego, La Jolla, California, United States of America
| | - Tanja Diemer
- Department of Psychiatry & Center for Circadian Biology, University of California, San Diego, La Jolla, California, United States of America
| | - David K. Welsh
- Veterans Affairs San Diego Healthcare System, San Diego, California, United States of America
- Department of Psychiatry & Center for Circadian Biology, University of California, San Diego, La Jolla, California, United States of America
| |
Collapse
|
30
|
Landgraf D, Long JE, Welsh DK. Depression-like behaviour in mice is associated with disrupted circadian rhythms in nucleus accumbens and periaqueductal grey. Eur J Neurosci 2015; 43:1309-20. [DOI: 10.1111/ejn.13085] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 09/10/2015] [Accepted: 09/24/2015] [Indexed: 02/01/2023]
Affiliation(s)
- Dominic Landgraf
- Veterans Affairs San Diego Healthcare System; San Diego CA USA
- Department of Psychiatry and Center for Circadian Biology; University of California, San Diego; 9500 Gilman Dr. San Diego CA MC-0603 USA
| | - Jaimie E. Long
- Veterans Affairs San Diego Healthcare System; San Diego CA USA
- Department of Psychiatry and Center for Circadian Biology; University of California, San Diego; 9500 Gilman Dr. San Diego CA MC-0603 USA
| | - David K. Welsh
- Veterans Affairs San Diego Healthcare System; San Diego CA USA
- Department of Psychiatry and Center for Circadian Biology; University of California, San Diego; 9500 Gilman Dr. San Diego CA MC-0603 USA
| |
Collapse
|
31
|
Kim TJ, Tuerkcan S, Ceballos A, Pratx G. Modular platform for low-light microscopy. BIOMEDICAL OPTICS EXPRESS 2015; 6:4585-4598. [PMID: 26601020 PMCID: PMC4646564 DOI: 10.1364/boe.6.004585] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 10/11/2015] [Accepted: 10/19/2015] [Indexed: 06/01/2023]
Abstract
Cell imaging using low-light techniques such as bioluminescence, radioluminescence, and low-excitation fluorescence has received increased attention, particularly due to broad commercialization of highly sensitive detectors. However, the dim signals are still regarded as difficult to image using conventional microscopes, where the only low-light microscope in the market is primarily optimized for bioluminescence imaging. Here, we developed a novel modular microscope that is cost-effective and suitable for imaging different low-light luminescence modes. Results show that this microscope system features excellent aberration correction capabilities and enhanced image resolution, where bioluminescence, radioluminescence and epifluorescence images were captured and compared with the commercial bioluminescence microscope.
Collapse
Affiliation(s)
- Tae Jin Kim
- Department of Radiation Oncology (Medical Physics), Stanford University, 1050 Arastradero Rd., Palo Alto, CA, 94304, USA
| | - Silvan Tuerkcan
- Department of Radiation Oncology (Medical Physics), Stanford University, 1050 Arastradero Rd., Palo Alto, CA, 94304, USA
| | - Andrew Ceballos
- Department of Electrical Engineering, Stanford University, 350 Serra Mall, Stanford, CA, 94305, USA
| | - Guillem Pratx
- Department of Radiation Oncology (Medical Physics), Stanford University, 1050 Arastradero Rd., Palo Alto, CA, 94304, USA
| |
Collapse
|
32
|
Schaub FX, Reza MS, Flaveny CA, Li W, Musicant AM, Hoxha S, Guo M, Cleveland JL, Amelio AL. Fluorophore-NanoLuc BRET Reporters Enable Sensitive In Vivo Optical Imaging and Flow Cytometry for Monitoring Tumorigenesis. Cancer Res 2015; 75:5023-33. [PMID: 26424696 DOI: 10.1158/0008-5472.can-14-3538] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 08/28/2015] [Indexed: 01/06/2023]
Abstract
Fluorescent proteins are widely used to study molecular and cellular events, yet this traditionally relies on delivery of excitation light, which can trigger autofluorescence, photoxicity, and photobleaching, impairing their use in vivo. Accordingly, chemiluminescent light sources such as those generated by luciferases have emerged, as they do not require excitation light. However, current luciferase reporters lack the brightness needed to visualize events in deep tissues. We report the creation of chimeric eGFP-NanoLuc (GpNLuc) and LSSmOrange-NanoLuc (OgNLuc) fusion reporter proteins coined LumiFluors, which combine the benefits of eGFP or LSSmOrange fluorescent proteins with the bright, glow-type bioluminescent light generated by an enhanced small luciferase subunit (NanoLuc) of the deep-sea shrimp Oplophorus gracilirostris. The intramolecular bioluminescence resonance energy transfer that occurs between NanoLuc and the fused fluorophore generates the brightest bioluminescent signal known to date, including improved intensity, sensitivity, and durable spectral properties, thereby dramatically reducing image acquisition times and permitting highly sensitive in vivo imaging. Notably, the self-illuminating and bifunctional nature of these LumiFluor reporters enables greatly improved spatiotemporal monitoring of very small numbers of tumor cells via in vivo optical imaging and also allows the isolation and analyses of single cells by flow cytometry. Thus, LumiFluor reporters are inexpensive, robust, noninvasive tools that allow for markedly improved in vivo optical imaging of tumorigenic processes.
Collapse
Affiliation(s)
- Franz X Schaub
- Department of Tumor Biology, Moffitt Cancer Center and Research Institute, Tampa, Florida
| | - Md Shamim Reza
- Department of Cancer Biology, The Scripps Research Institute, Scripps Florida, Jupiter, Florida
| | - Colin A Flaveny
- Department of Pharmacological & Physiological Science, School of Medicine, Saint Louis University, St. Louis, Missouri
| | - Weimin Li
- Department of Tumor Biology, Moffitt Cancer Center and Research Institute, Tampa, Florida
| | - Adele M Musicant
- UNC Biological and Biomedical Sciences Graduate Program, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Sany Hoxha
- Scripps Graduate Program, The Scripps Research Institute, Scripps Florida, Jupiter, Florida
| | - Min Guo
- Department of Cancer Biology, The Scripps Research Institute, Scripps Florida, Jupiter, Florida
| | - John L Cleveland
- Department of Tumor Biology, Moffitt Cancer Center and Research Institute, Tampa, Florida
| | - Antonio L Amelio
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina. Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
| |
Collapse
|
33
|
Lande-Diner L, Stewart-Ornstein J, Weitz CJ, Lahav G. Single-cell analysis of circadian dynamics in tissue explants. Mol Biol Cell 2015; 26:3940-5. [PMID: 26269583 PMCID: PMC4710227 DOI: 10.1091/mbc.e15-06-0403] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 08/04/2015] [Indexed: 11/23/2022] Open
Abstract
Studying signaling dynamics in single cells in vivo is critical to understanding how cells act and interact in 3D environments. Experimental and computational tools to quantify a circadian reporter in single cells in intact tissues for >1 wk are used to analyze the period, amplitude, and synchrony of circadian rhythms in vivo. Tracking molecular dynamics in single cells in vivo is instrumental to understanding how cells act and interact in tissues. Current tissue imaging approaches focus on short-term observation and typically nonendogenous or implanted samples. Here we develop an experimental and computational setup that allows for single-cell tracking of a transcriptional reporter over a period of >1 wk in the context of an intact tissue. We focus on the peripheral circadian clock as a model system and measure the circadian signaling of hundreds of cells from two tissues. The circadian clock is an autonomous oscillator whose behavior is well described in isolated cells, but in situ analysis of circadian signaling in single cells of peripheral tissues is as-yet uncharacterized. Our approach allowed us to investigate the oscillatory properties of individual clocks, determine how these properties are maintained among different cells, and assess how they compare to the population rhythm. These experiments, using a wide-field microscope, a previously generated reporter mouse, and custom software to track cells over days, suggest how many signaling pathways might be quantitatively characterized in explant models.
Collapse
Affiliation(s)
- Laura Lande-Diner
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115
| | | | - Charles J Weitz
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115
| | - Galit Lahav
- Department of Systems Biology, Harvard Medical School, Boston, MA 02115
| |
Collapse
|
34
|
Ramji R, Cheong CF, Hirata H, Rahman ARA, Lim CT. Rapid quantification of live cell receptors using bioluminescence in a flow-based microfluidic device. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2015; 11:943-951. [PMID: 25336403 DOI: 10.1002/smll.201401674] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 09/08/2014] [Indexed: 06/04/2023]
Abstract
The number of receptors expressed by cells plays an important role in controlling cell signaling events, thus determining its behaviour, state and fate. Current methods of quantifying receptors on cells are either laborious or do not maintain the cells in their native form. Here, a method integrating highly sensitive bioluminescence, high precision microfluidics and small footprint of lensfree optics is developed to quantify cell surface receptors. This method is safe to use, less laborious, and faster than the conventional radiolabelling and near field scanning methods. It is also more sensitive than fluorescence based assays and is ideal for high throughput screening. In quantifying β(1) adrenergic receptors expressed on the surface of H9c2 cardiomyocytes, this method yields receptor numbers from 3.12 × 10(5) to 9.36 × 10(5) receptors/cell which are comparable with current methods. This can serve as a very good platform for rapid quantification of receptor numbers in ligand/drug binding and receptor characterization studies, which is an important part of pharmaceutical and biological research.
Collapse
Affiliation(s)
- Ramesh Ramji
- Department of Biomedical Engineering, 9 Engineering Drive 1, Block EA, #03-12, National University of Singapore, Singapore, 117575
| | | | | | | | | |
Collapse
|
35
|
Choe HK, Chun SK, Kim J, Kim D, Kim HD, Kim K. Real-Time GnRH Gene Transcription in GnRH Promoter-Driven Luciferase-Expressing Transgenic Mice: Effect of Kisspeptin. Neuroendocrinology 2015; 102:194-9. [PMID: 25571901 DOI: 10.1159/000371805] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 12/25/2014] [Indexed: 11/19/2022]
Abstract
Pulsatile secretion of hypothalamic gonadotropin-releasing hormone (GnRH) is indispensable for controlling proper pituitary gonadotrope functions; however, the mechanism underlying GnRH pulse generation remains largely unknown. It is important to understand the cellular oscillator in individual GnRH neurons and temporal synchronization among GnRH neurons. In this brief review, we summarize our recent findings on episodic GnRH gene transcription at the single GnRH neuron level and in synchronized multicellular burst in relation to the temporal pattern of GnRH secretion. We also detail the effects of kisspeptin on ultradian rhythmic GnRH gene transcription and secretion. We extend our discussion to the hierarchical interaction between circadian and ultradian rhythms. Taken together, the current review elucidates the genomic control of GnRH pulse generation in hypothalamic neurons.
Collapse
Affiliation(s)
- Han Kyoung Choe
- Department of Brain and Cognitive Sciences and School of Biological Sciences, Seoul National University, Seoul, South Korea
| | | | | | | | | | | |
Collapse
|
36
|
Herzog ED, Kiss IZ, Mazuski C. Measuring synchrony in the mammalian central circadian circuit. Methods Enzymol 2014; 552:3-22. [PMID: 25707270 DOI: 10.1016/bs.mie.2014.10.042] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Circadian clocks control daily rhythms in physiology and behavior across all phyla. These rhythms are intrinsic to individual cells that must synchronize to their environment and to each other to anticipate daily events. Recent advances in recording from large numbers of cells for many circadian cycles have enabled researchers to begin to evaluate the mechanisms and consequences of intercellular circadian synchrony. Consequently, methods have been adapted to estimate the period, phase, and amplitude of individual circadian cells and calculate synchrony between cells. Stable synchronization requires that the cells share a common period. As a result, synchronized cells maintain constant phase relationships to each (e.g., with cell 1 peaking an hour before cell 2 each cycle). This chapter reviews how circadian rhythms are recorded from single mammalian cells and details methods for measuring their period and phase synchrony. These methods have been useful, for example, in showing that specific neuropeptides are essential to maintain synchrony among circadian cells.
Collapse
Affiliation(s)
- Erik D Herzog
- Department of Biology, Washington University, St. Louis, Missouri, USA.
| | - István Z Kiss
- Department of Chemistry, Saint Louis University, St. Louis, Missouri, USA
| | - Cristina Mazuski
- Department of Biology, Washington University, St. Louis, Missouri, USA
| |
Collapse
|
37
|
Jathoul AP, Grounds H, Anderson JC, Pule MA. A dual-color far-red to near-infrared firefly luciferin analogue designed for multiparametric bioluminescence imaging. Angew Chem Int Ed Engl 2014; 53:13059-63. [PMID: 25266918 PMCID: PMC4501308 DOI: 10.1002/anie.201405955] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 09/03/2014] [Indexed: 11/23/2022]
Abstract
Red-shifted bioluminescent emitters allow improved in vivo tissue penetration and signal quantification, and have led to the development of beetle luciferin analogues that elicit red-shifted bioluminescence with firefly luciferase (Fluc). However, unlike natural luciferin, none have been shown to emit different colors with different luciferases. We have synthesized and tested the first dual-color, far-red to near-infrared (nIR) emitting analogue of beetle luciferin, which, akin to natural luciferin, exhibits pH dependent fluorescence spectra and emits bioluminescence of different colors with different engineered Fluc enzymes. Our analogue produces different far-red to nIR emission maxima up to λ(max)=706 nm with different Fluc mutants. This emission is the most red-shifted bioluminescence reported without using a resonance energy transfer acceptor. This improvement should allow tissues to be more effectively probed using multiparametric deep-tissue bioluminescence imaging.
Collapse
Affiliation(s)
- Amit P Jathoul
- Department of Haematology, UCL Cancer Institute and NIHR University College London Hospitals Biomedical Research CentreLondon, WC1E 6BT (UK)
| | - Helen Grounds
- Department of Chemistry, University College LondonLondon, WC1E 6BT (UK)
| | - James C Anderson
- Department of Chemistry, University College LondonLondon, WC1E 6BT (UK)
| | - Martin A Pule
- Department of Haematology, UCL Cancer Institute and NIHR University College London Hospitals Biomedical Research CentreLondon, WC1E 6BT (UK)
| |
Collapse
|
38
|
Light-induced rapid Ca²⁺ response and MAPK phosphorylation in the cells heterologously expressing human OPN5. Sci Rep 2014; 4:5352. [PMID: 24941910 PMCID: PMC4062899 DOI: 10.1038/srep05352] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 04/16/2014] [Indexed: 12/26/2022] Open
Abstract
Molecular imaging is a powerful tool for investigating intracellular signalling, but it is difficult to acquire conventional fluorescence imaging from photoreceptive cells. Here we demonstrated that human opsin5 (OPN5) photoreceptor mediates light-induced Ca(2+) response in human embryonic kidney (HEK293) and mouse neuroblastoma (Neuro2a) cell lines using a luminescence imaging system with a fluorescent indicator and a newly synthesized bioluminescent indicator. Weak light fluorescence and bioluminescence imaging revealed rapid and transient light-stimulated Ca(2+) release from thapsigargin-sensitive Ca(2+) stores, whereas long-lasting Ca(2+) elevation was observed using a conventional fluorescence imaging system. Bioluminescence imaging also demonstrated that OPN5 activation in HEK293 cells induced a decrease in pertussis toxin-sensitive cAMP, confirming previous reports. In addition, ultraviolet radiation induced the phosphorylation of mitogen-activated protein kinases when OPN5 was stimulated in Neuro2a cells. These findings suggest that the combination of these imaging approaches may provide a new means to investigate the physiological characteristics of photoreceptors.
Collapse
|
39
|
Tataroglu O, Emery P. Studying circadian rhythms in Drosophila melanogaster. Methods 2014; 68:140-50. [PMID: 24412370 DOI: 10.1016/j.ymeth.2014.01.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 01/02/2014] [Indexed: 11/25/2022] Open
Abstract
Circadian rhythms have a profound influence on most bodily functions: from metabolism to complex behaviors. They ensure that all these biological processes are optimized with the time-of-day. They are generated by endogenous molecular oscillators that have a period that closely, but not exactly, matches day length. These molecular clocks are synchronized by environmental cycles such as light intensity and temperature. Drosophila melanogaster has been a model organism of choice to understand genetically, molecularly and at the level of neural circuits how circadian rhythms are generated, how they are synchronized by environmental cues, and how they drive behavioral cycles such as locomotor rhythms. This review will cover a wide range of techniques that have been instrumental to our understanding of Drosophila circadian rhythms, and that are essential for current and future research.
Collapse
Affiliation(s)
- Ozgur Tataroglu
- Department of Neurobiology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, United States
| | - Patrick Emery
- Department of Neurobiology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, United States.
| |
Collapse
|
40
|
Abstract
Like neurons in the suprachiasmatic nucleus (SCN), the master circadian pacemaker in the brain, single fibroblasts can function as independent oscillators. In the SCN, synaptic and paracrine signaling among cells creates a robust, synchronized circadian oscillation, whereas there is no evidence for such integration in fibroblast cultures. However, interactions among single-cell fibroblast oscillators cannot be completely excluded, because fibroblasts were not isolated in previous work. In this study, we tested the autonomy of fibroblasts as single-cell circadian oscillators in high- and low-density culture, by single-cell imaging of cells from PER2::LUC circadian reporter mice. We found greatly reduced PER2::LUC rhythmicity in low-density cultures, which could result from lack of either constitutive or rhythmic paracrine signals from neighboring fibroblasts. To discriminate between these 2 possibilities, we mixed PER2::LUC wild-type (WT) cells with nonluminescent, nonrhythmic Bmal1-/- cells, so that density of rhythmic cells was low but overall cell density remained high. In this condition, WT cells showed clear rhythmicity similar to high-density cultures. We also mixed PER2::LUC WT cells with nonluminescent, long period Cry2-/- cells. In this condition, WT cells showed a period no different from cells cultured with rhythmic WT cells or nonrhythmic Bmal1-/- cells. In previous work, we found that low K⁺ suppresses fibroblast rhythmicity, and we and others have found that either low K⁺ or low Ca²⁺ suppresses SCN rhythmicity. Therefore, we attempted to rescue rhythmicity of low-density fibroblasts with high K⁺ (21 mM), high Ca²⁺ (3.6 mM), or conditioned medium. Conditioned medium from high-density fibroblast cultures rescued rhythmicity of low-density cultures, whereas high K⁺ or Ca²⁺ medium did not consistently rescue rhythmicity. These data suggest that fibroblasts require paracrine signals from adjacent cells for normal expression of rhythmicity, but that these signals do not have to be rhythmic, and that rhythmic signals from other cells do not affect the intrinsic periods of fibroblasts.
Collapse
Affiliation(s)
- Takako Noguchi
- Department of Psychiatry and Center for Chronobiology, University of California, San Diego, 9500 Gilman Drive MC0603, La Jolla, CA 92093-0603, USA
| | - Lexie L. Wang
- Department of Psychiatry and Center for Chronobiology, University of California, San Diego, 9500 Gilman Drive MC0603, La Jolla, CA 92093-0603, USA
| | - David K. Welsh
- Department of Psychiatry and Center for Chronobiology, University of California, San Diego, 9500 Gilman Drive MC0603, La Jolla, CA 92093-0603, USA
- Veterans Affairs San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA 92161, USA
| |
Collapse
|
41
|
Godinat A, Park HM, Miller SC, Cheng K, Hanahan D, Sanman LE, Bogyo M, Yu A, Nikitin GF, Stahl A, Dubikovskaya EA. A biocompatible in vivo ligation reaction and its application for noninvasive bioluminescent imaging of protease activity in living mice. ACS Chem Biol 2013; 8:987-99. [PMID: 23463944 DOI: 10.1021/cb3007314] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The discovery of biocompatible reactions had a tremendous impact on chemical biology, allowing the study of numerous biological processes directly in complex systems. However, despite the fact that multiple biocompatible reactions have been developed in the past decade, very few work well in living mice. Here we report that D-cysteine and 2-cyanobenzothiazoles can selectively react with each other in vivo to generate a luciferin substrate for firefly luciferase. The success of this "split luciferin" ligation reaction has important implications for both in vivo imaging and biocompatible labeling strategies. First, the production of a luciferin substrate can be visualized in a live mouse by bioluminescence imaging (BLI) and furthermore allows interrogation of targeted tissues using a "caged" luciferin approach. We therefore applied this reaction to the real-time noninvasive imaging of apoptosis associated with caspase 3/7. Caspase-dependent release of free D-cysteine from the caspase 3/7 peptide substrate Asp-Glu-Val-Asp-D-Cys (DEVD-(D-Cys)) allowed selective reaction with 6-amino-2-cyanobenzothiazole (NH(2)-CBT) in vivo to form 6-amino-D-luciferin with subsequent light emission from luciferase. Importantly, this strategy was found to be superior to the commercially available DEVD-aminoluciferin substrate for imaging of caspase 3/7 activity. Moreover, the split luciferin approach enables the modular construction of bioluminogenic sensors, where either or both reaction partners could be caged to report on multiple biological events. Lastly, the luciferin ligation reaction is 3 orders of magnitude faster than Staudinger ligation, suggesting further applications for both bioluminescence and specific molecular targeting in vivo.
Collapse
Affiliation(s)
- Aurélien Godinat
- Institute of Chemical Sciences
and Engineering, Swiss Federal Institute of Technology of Lausanne, LCBIM, CH-1015 Lausanne, Switzerland
| | - Hyo Min Park
- Department of Nutritional Science
and Toxicology, University of California Berkeley, Berkeley, California 94720, United States
| | - Stephen C. Miller
- Department of Biochemistry and
Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States
| | - Ke Cheng
- The Swiss Institute for Experimental
Cancer Research, School of Life Sciences, Swiss Federal Institute of Technology of Lausanne, CH-1015 Lausanne,
Switzerland
| | - Douglas Hanahan
- The Swiss Institute for Experimental
Cancer Research, School of Life Sciences, Swiss Federal Institute of Technology of Lausanne, CH-1015 Lausanne,
Switzerland
| | | | | | - Allen Yu
- Department of Nutritional Science
and Toxicology, University of California Berkeley, Berkeley, California 94720, United States
| | - Gennady F. Nikitin
- Institute of Chemical Sciences
and Engineering, Swiss Federal Institute of Technology of Lausanne, LCBIM, CH-1015 Lausanne, Switzerland
| | - Andreas Stahl
- Department of Nutritional Science
and Toxicology, University of California Berkeley, Berkeley, California 94720, United States
| | - Elena A. Dubikovskaya
- Institute of Chemical Sciences
and Engineering, Swiss Federal Institute of Technology of Lausanne, LCBIM, CH-1015 Lausanne, Switzerland
| |
Collapse
|