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Sasso A, Capaccio A, Rusciano G. Exploring Reliable and Efficient Plasmonic Nanopatterning for Surface- and Tip-Enhanced Raman Spectroscopies. Int J Mol Sci 2023; 24:16164. [PMID: 38003354 PMCID: PMC10671507 DOI: 10.3390/ijms242216164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 11/04/2023] [Accepted: 11/07/2023] [Indexed: 11/26/2023] Open
Abstract
Surface-enhanced Raman scattering (SERS) is of growing interest for a wide range of applications, especially for biomedical analysis, thanks to its sensitivity, specificity, and multiplexing capabilities. A crucial role for successful applications of SERS is played by the development of reproducible, efficient, and facile procedures for the fabrication of metal nanostructures (SERS substrates). Even more challenging is to extend the fabrication techniques of plasmonic nano-textures to atomic force microscope (AFM) probes to carry out tip-enhanced Raman spectroscopy (TERS) experiments, in which spatial resolution below the diffraction limit is added to the peculiarities of SERS. In this short review, we describe recent studies performed by our group during the last ten years in which novel nanofabrication techniques have been successfully applied to SERS and TERS experiments for studying bio-systems and molecular species of environmental interest.
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Affiliation(s)
- Antonio Sasso
- Department of Physics “E. Pancini”, University of Naples “Federico II”, 80126 Naples, Italy; (A.C.); (G.R.)
| | - Angela Capaccio
- Department of Physics “E. Pancini”, University of Naples “Federico II”, 80126 Naples, Italy; (A.C.); (G.R.)
- Institute of Food Sciences, URT-CNR Department of Biology, University of Naples “Federico II”, 80126 Naples, Italy
| | - Giulia Rusciano
- Department of Physics “E. Pancini”, University of Naples “Federico II”, 80126 Naples, Italy; (A.C.); (G.R.)
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2
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Chen G, Obal D. Detecting and measuring of GPCR signaling - comparison of human induced pluripotent stem cells and immortal cell lines. Front Endocrinol (Lausanne) 2023; 14:1179600. [PMID: 37293485 PMCID: PMC10244570 DOI: 10.3389/fendo.2023.1179600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Accepted: 04/12/2023] [Indexed: 06/10/2023] Open
Abstract
G protein-coupled receptors (GPCRs) are a large family of transmembrane proteins that play a major role in many physiological processes, and thus GPCR-targeted drug development has been widely promoted. Although research findings generated in immortal cell lines have contributed to the advancement of the GPCR field, the homogenous genetic backgrounds, and the overexpression of GPCRs in these cell lines make it difficult to correlate the results with clinical patients. Human induced pluripotent stem cells (hiPSCs) have the potential to overcome these limitations, because they contain patient specific genetic information and can differentiate into numerous cell types. To detect GPCRs in hiPSCs, highly selective labeling and sensitive imaging techniques are required. This review summarizes existing resonance energy transfer and protein complementation assay technologies, as well as existing and new labeling methods. The difficulties of extending existing detection methods to hiPSCs are discussed, as well as the potential of hiPSCs to expand GPCR research towards personalized medicine.
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Affiliation(s)
- Gaoxian Chen
- Department of Anesthesiology, Perioperative, and Pain Medicine, Stanford University, Stanford, CA, United States
- Stanford Cardiovascular Institute, Stanford University, Stanford, CA, United States
| | - Detlef Obal
- Department of Anesthesiology, Perioperative, and Pain Medicine, Stanford University, Stanford, CA, United States
- Stanford Cardiovascular Institute, Stanford University, Stanford, CA, United States
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3
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Porto-Pedrosa MLM, de Miranda CDM, Lopes ME, Nakagaki BN, Mafra K, de Paula CMP, Diniz AB, Costa KMDO, Antunes MM, Oliveira AG, Balderas R, Lopes RP, Menezes GB. High-dimensional intravital microscopy reveals major changes in splenic immune system during postnatal development. Front Immunol 2022; 13:1002919. [PMID: 36531990 PMCID: PMC9755845 DOI: 10.3389/fimmu.2022.1002919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 11/10/2022] [Indexed: 12/05/2022] Open
Abstract
Spleen is a key organ for immunologic surveillance, acting as a firewall for antigens and parasites that spread through the blood. However, how spleen leukocytes evolve across the developmental phase, and how they spatially organize and interact in vivo is still poorly understood. Using a novel combination of selected antibodies and fluorophores to image in vivo the spleen immune environment, we described for the first time the dynamics of immune development across postnatal period. We found that spleens from adults and infants had similar numbers and arrangement of lymphoid cells. In contrast, splenic immune environment in newborns is sharply different from adults in almost all parameters analysed. Using this in vivo approach, B cells were the most frequent subtype throughout the development. Also, we revealed how infections - using a model of malaria - can change the spleen immune profile in adults and infants, which could become the key to understanding different severity grades of infection. Our new imaging solutions can be extremely useful for different groups in all areas of biological investigation, paving a way for new intravital approaches and advances.
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Affiliation(s)
- Maria Luiza Mundim Porto-Pedrosa
- Center for Gastrointestinal Biology, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Camila Dutra Moreira de Miranda
- Center for Gastrointestinal Biology, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Mateus Eustáquio Lopes
- Center for Gastrointestinal Biology, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Brenda Naemi Nakagaki
- Center for Gastrointestinal Biology, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Kassiana Mafra
- Center for Gastrointestinal Biology, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Cristina Maria Pinto de Paula
- Center for Gastrointestinal Biology, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Ariane Barros Diniz
- Center for Gastrointestinal Biology, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Karen Marques de Oliveira Costa
- Center for Gastrointestinal Biology, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Maisa Mota Antunes
- Center for Gastrointestinal Biology, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - André Gustavo Oliveira
- Departamento de Fisiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Robert Balderas
- BD Biosciences, Department of Biological Sciences, San Jose, CA, United States
| | - Rodrigo Pestana Lopes
- BD Biosciences, Department of Medical & Scientific Affairs, São Paulo, São Paulo, Brazil
| | - Gustavo Batista Menezes
- Center for Gastrointestinal Biology, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil,*Correspondence: Gustavo Batista Menezes,
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4
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Approach to map nanotopography of cell surface receptors. Commun Biol 2022; 5:218. [PMID: 35264712 PMCID: PMC8907216 DOI: 10.1038/s42003-022-03152-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 02/09/2022] [Indexed: 12/18/2022] Open
Abstract
Cells communicate with their environment via surface receptors, but nanoscopic receptor organization with respect to complex cell surface morphology remains unclear. This is mainly due to a lack of accessible, robust and high-resolution methods. Here, we present an approach for mapping the topography of receptors at the cell surface with nanometer precision. The method involves coating glass coverslips with glycine, which preserves the fine membrane morphology while allowing immobilized cells to be positioned close to the optical surface. We developed an advanced and simplified algorithm for the analysis of single-molecule localization data acquired in a biplane detection scheme. These advancements enable direct and quantitative mapping of protein distribution on ruffled plasma membranes with near isotropic 3D nanometer resolution. As demonstrated successfully for CD4 and CD45 receptors, the described workflow is a straightforward quantitative technique to study molecules and their interactions at the complex surface nanomorphology of differentiated metazoan cells. A super-resolution localisation-based method is shown to map receptor topography in immune cells, which allows quantitative study of molecules and their interactions at the complex surface nanomorphology of cells.
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5
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Raveendran AV, Sankeerthana P, Jayaraj A, Chinna Ayya Swamy P. Recent Developments on BODIPY Based Chemosensors for the Detection of Group IIB Metal ions. RESULTS IN CHEMISTRY 2022. [DOI: 10.1016/j.rechem.2022.100297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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6
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Kleiber A, Kraus D, Henkel T, Fritzsche W. Review: tomographic imaging flow cytometry. LAB ON A CHIP 2021; 21:3655-3666. [PMID: 34514484 DOI: 10.1039/d1lc00533b] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Within the last decades, conventional flow cytometry (FC) has evolved as a powerful measurement method in clinical diagnostics, biology, life sciences and healthcare. Imaging flow cytometry (IFC) extends the power of traditional FC by adding high resolution optical and spectroscopic information. However, the conventional IFC only provides a 2D projection of a 3D object. To overcome this limitation, tomographic imaging flow cytometry (tIFC) was developed to access 3D information about the target particles. The goal of tIFC is to visualize surfaces and internal structures in a holistic way. This review article gives an overview of the past and current developments in tIFC.
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Affiliation(s)
- Andreas Kleiber
- Leibniz Institute of Photonic Technology, Albert-Einstein-Straße 9, D-07745 Jena, Germany
| | - Daniel Kraus
- Leibniz Institute of Photonic Technology, Albert-Einstein-Straße 9, D-07745 Jena, Germany
| | - Thomas Henkel
- Leibniz Institute of Photonic Technology, Albert-Einstein-Straße 9, D-07745 Jena, Germany
| | - Wolfgang Fritzsche
- Leibniz Institute of Photonic Technology, Albert-Einstein-Straße 9, D-07745 Jena, Germany
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7
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Han C, Tang Y, Xie Z, Liu L, Feng J, Hu S. Fast structured illumination microscopy with a large dynamic measurement range. APPLIED OPTICS 2021; 60:5169-5176. [PMID: 34143086 DOI: 10.1364/ao.424081] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 05/17/2021] [Indexed: 06/12/2023]
Abstract
Fast structured illumination microscopy plays an important role in micro-nano detection due to the features of high accuracy, high efficiency, and excellent adaptability. The existing method utilizes the linear region of the axial modulation response curve (AMR), and by building the relationship between the modulation and the real height, achieves topography recovery. However, the traditional method is limited to narrow dynamic measurement range due to the linear region of the AMR being very short. In this paper, a double-differential fast structured illumination microscopy (DDFSIM) is proposed. By introducing two additional detectable branches for building the double-differential axial modulation response curve (DDAMR), the proposed method can obtain a large dynamic measurement range. In the measurement, three charge-coupled devices are respectively placed in and behind and before the focal plane to generate three axial modulation response curves. Three AMRs are used to set up the DDAMR, which has a large dynamic measurement range. Through simulation and experimental verification, the measurement range of DDFSIM is twice that of the conventional method under the same system parameters.
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8
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Zhou L, Yu X, Feng PXL, Li J, Xie H. A MEMS lens scanner based on serpentine electrothermal bimorph actuators for large axial tuning. OPTICS EXPRESS 2020; 28:23439-23453. [PMID: 32752341 PMCID: PMC7470678 DOI: 10.1364/oe.400363] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Confocal microscopes and two-photon microscopes are powerful tools for early cancer diagnosis because of their high-resolution 3D imaging capability, but applying them for clinical use in internal organs is hindered by the lack of axially tunable lens modules with small size, high image quality and large tuning range. This paper reports a compact MEMS lens scanner that has the potential to overcome this limitation. The MEMS lens scanner consists of a MEMS microstage and a microlens. The MEMS microstage is based on a unique serpentine inverted-series-connected (ISC) electrothermal bimorph actuator design. The microlens is an aspheric glass lens to ensure optical quality. The MEMS microstage has been fabricated and the lens scanner has been successfully assembled. The entire lens scanner is circular with an outer diameter of 4.4 mm and a clear optical aperture of 1.8 mm. Experiments show that the tunable range reaches over 200 µm at only 10.5 V and the stiffness of the microstage is 6.2 N/m. Depth scan imaging by the MEMS lens scanner has also been demonstrated with a 2.2 µm resolution, only limited by the available resolution target.
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Affiliation(s)
- Liang Zhou
- Department of Electrical and Computer Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Xiaomin Yu
- College of Electronic Engineering, Chengdu University of Information Technology, Chengdu 610225, Sichuan, China
| | - Philip X.-L. Feng
- Department of Electrical and Computer Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Jianhua Li
- School of Mechatronical Engineering, Beijing Institute of Technology, 100081 Beijing, China
| | - Huikai Xie
- School of Information and Electronics, Beijing Institute of Technology, 100081 Beijing, China
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9
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Panagopoulou MS, Wark AW, Birch DJS, Gregory CD. Phenotypic analysis of extracellular vesicles: a review on the applications of fluorescence. J Extracell Vesicles 2020; 9:1710020. [PMID: 32002172 PMCID: PMC6968689 DOI: 10.1080/20013078.2019.1710020] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 12/18/2019] [Accepted: 12/21/2019] [Indexed: 12/22/2022] Open
Abstract
Extracellular vesicles (EVs) have numerous potential applications in the field of healthcare and diagnostics, and research into their biological functions is rapidly increasing. Mainly because of their small size and heterogeneity, there are significant challenges associated with their analysis and despite overt evidence of the potential of EVs in clinical diagnostic practice, guidelines for analytical procedures have not yet been properly established. Here, we present an overview of the main methods for studying the properties of EVs based on the principles of fluorescence. Setting aside the isolation, purification and physicochemical characterization strategies which answer questions about the size, surface charge and stability of EVs (reviewed elsewhere), we focus on available optical tools that enable the direct analysis of phenotype and mechanisms of interaction with tissues. In brief, the topics on which we elaborate range from the most popular approaches such as nanoparticle tracking analysis and flow cytometry, to less commonly used techniques such as fluorescence depolarization and microarrays as well as emerging areas such as fast fluorescence lifetime imaging microscopy (FLIM). We highlight that understanding the strengths and limitations of each method is essential for choosing the most appropriate combination of analytical tools. Finally, future directions of this rapidly developing area of medical diagnostics are discussed.
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Affiliation(s)
- Maria S. Panagopoulou
- University of Edinburgh Centre for Inflammation Research, The Queen’s Medical Research Institute, Edinburgh, UK
| | - Alastair W. Wark
- Centre for Molecular Nanometrology, Technology and Innovation Centre, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, UK
| | - David J S Birch
- Photophysics Group, Department of Physics, SUPA, University of Strathclyde, Glasgow, UK
| | - Christopher D. Gregory
- University of Edinburgh Centre for Inflammation Research, The Queen’s Medical Research Institute, Edinburgh, UK
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10
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3D-Imaging of Whole Neuronal and Vascular Networks of the Human Dental Pulp via CLARITY and Light Sheet Microscopy. Sci Rep 2019; 9:10860. [PMID: 31350423 PMCID: PMC6659648 DOI: 10.1038/s41598-019-47221-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 07/12/2019] [Indexed: 01/10/2023] Open
Abstract
Direct visualization of the spatial relationships of the dental pulp tissue at the whole-organ has remained challenging. CLARITY (Clear Lipid-exchanged Acrylamide Tissue hYdrogel) is a tissue clearing method that has enabled successful 3-dimensional (3D) imaging of intact tissues with high-resolution and preserved anatomic structures. We used CLARITY to study the whole human dental pulp with emphasis on the neurovascular components. Dental pulps from sound teeth were CLARITY-cleared, immunostained for PGP9.5 and CD31, as markers for peripheral neurons and blood vessels, respectively, and imaged with light sheet microscopy. Visualization of the whole dental pulp innervation and vasculature was achieved. Innervation comprised 40% of the dental pulp volume and the vasculature another 40%. Marked innervation morphological differences between uni- and multiradicular teeth were found, also distinct neurovascular interplays. Quantification of the neural and vascular structures distribution, diameter and area showed that blood vessels in the capillary size range was twice as high as that of nerve fibers. In conclusion whole CLARITY-cleared dental pulp samples revealed 3D-morphological neurovascular interactions that could not be visualized with standard microscopy. This represents an outstanding tool to study the molecular and structural intricacies of whole dental tissues in the context of disease and treatment methods.
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11
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Kreutz A, Barger N. Maximizing Explanatory Power in Stereological Data Collection: A Protocol for Reliably Integrating Optical Fractionator and Multiple Immunofluorescence Techniques. Front Neuroanat 2018; 12:73. [PMID: 30425623 PMCID: PMC6218486 DOI: 10.3389/fnana.2018.00073] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 08/20/2018] [Indexed: 11/21/2022] Open
Abstract
With the promise of greater reliability and replicability of estimates, stereological techniques have revolutionized data collection in the neurosciences. At the same time, improvements in immunohistochemistry and fluorescence imaging technologies have facilitated easy application of immunofluorescence protocols, allowing for isolation of multiple target proteins in one tissue sample. Combining multiple immunofluorescence labeling with stereological data collection can provide a powerful tool to maximize explanatory power and efficiency, while minimizing tissue use. Multiple cell classes, subtypes of larger populations, or different cell states can be quantified in one case and even in one sampling run. Here, we present a protocol integrating stereological data collection and multiple immunofluorescence using commonly employed widefield epifluorescence filter sets, optimized for blue (DAPI), green (FITC), and far red (CY5) channels. Our stereological protocol has been designed to accommodate the challenges of fluorescence imaging to overcome limitations like fixed filter sets, photobleaching, and uneven immunolabeling. To enhance fluorescence signal for stereological sampling, our immunolabeling protocol utilizes both high temperature antigen retrieval to improve primary antibody binding and secondary antibodies conjugated to optimally stable fluorophores. To illustrate the utility of this approach, we estimated the number of Ctip2 immunoreactive subcerebral projection neurons and NeuN immunoreactive neurons in rat cerebral cortex at postnatal day 10. We used DAPI (blue) to define the neocortex, anti-NeuN (far red) to identify neurons, and co-labeling of anti-Ctip2 (green) and anti-NeuN (far red) to isolate only subcerebral projection neurons. Our protocol resulted in estimates with low sampling error (CE < 0.05) and high intrarater reliability (ICC > 0.98) that fall within the range of published values, attesting to its efficacy. We show our immunofluorescence techniques can be used to reliably identify other cell types, e.g., different glial cell classes, to highlight the broader applications of our approach. The flexibility of the technique, increasingly reduced costs of fluorescence technologies, and savings in experimental time and tissue use make this approach valuable for neuroscientists interested in incorporating stereology to ask precise neurophysiological and neuroanatomical questions.
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Affiliation(s)
- Anna Kreutz
- Neuroscience Graduate Program, University of California, Davis, Davis, CA, United States
| | - Nicole Barger
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Sacramento, CA, United States
- MIND Institute, University of California, Davis, Sacramento, CA, United States
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12
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Parker A, Chessum L, Mburu P, Sanderson J, Bowl MR. Light and Electron Microscopy Methods for Examination of Cochlear Morphology in Mouse Models of Deafness. ACTA ACUST UNITED AC 2016; 6:272-306. [PMID: 27584554 DOI: 10.1002/cpmo.10] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Mice are an invaluable model organism for the study of auditory function. Even though there are differences in size and frequency response, the anatomy and physiology of the mouse and human ear are remarkably similar. In addition, the tools available for genetic manipulation in the mouse have enabled the generation of models carrying mutations in orthologous human deafness-causing genes, helping to validate these lesions and assess their functional consequence. Reciprocally, novel gene mutations discovered to cause auditory deficits in the mouse highlight potential new loci for human hearing loss, and expand our basic knowledge of the mechanisms and pathways important for the function of the mammalian ear. Microscopy and imaging are invaluable techniques that allow detailed characterization of cochlear pathologies associated with particular gene mutations. However, the highly organized, delicate, and intricate structures responsible for transduction of sound waves into nerve impulses are encapsulated in one of the hardest bones in the body - the temporal bone. This makes sample preparation without damage to the soft tissue, be it from dissection or processing, somewhat challenging. Fortunately, there are numerous methods for achieving high-quality images of the mouse cochlea. Reported in this article are a selection of sample preparation and imaging techniques that can be used routinely to assess cochlear morphology. Several protocols are also described for immunodetection of proteins in the cochlea. In addition, the advantages and disadvantages between different imaging platforms and their suitability for different types of microscopic examination are highlighted. © 2016 by John Wiley & Sons, Inc.
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Affiliation(s)
- Andrew Parker
- Mammalian Genetics Unit, MRC Harwell, Oxfordshire, United Kingdom
| | - Lauren Chessum
- Mammalian Genetics Unit, MRC Harwell, Oxfordshire, United Kingdom
| | - Philomena Mburu
- Mammalian Genetics Unit, MRC Harwell, Oxfordshire, United Kingdom
| | - Jeremy Sanderson
- Mammalian Genetics Unit, MRC Harwell, Oxfordshire, United Kingdom
| | - Michael R Bowl
- Mammalian Genetics Unit, MRC Harwell, Oxfordshire, United Kingdom
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13
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Divi KV, Ward Y, Poirier MC, Olivero OA. Use of Ciliogenesis to Detect Aneugens: The Role of Primary Cilia. ACTA ACUST UNITED AC 2015; 66:3.13.1-3.13.8. [PMID: 26523475 DOI: 10.1002/0471140856.tx0313s66] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Primary cilia arise from the centrosomes of quiescent or post-mitotic cells, and serve as sensory organelles that communicate mechanical and chemical stimuli from the environment to the interior of the cell. Cilium formation may, therefore, become a useful end point signaling exposure to genotoxins or aneugens. Here we have used the aneugen, zidovudine (AZT), an antiretroviral drug that induces DNA replication arrest and centrosomal amplification (>2 centrosomes per quiescent cell), to evaluate cilia formation in retinal epithelial (pigmented) cells. Since cilia are derived from centrosomes, and aneugens can induce centrosomal amplification, the production of multiple cilia arising from multiple centrosomes may reveal the aneugenic nature of the agents. Cells were exposed to AZT to induce centrosomal amplification, cultured without serum to allow the centrioles to develop cilia, and immunostained to visualize cilia and centrosomes. Nuclear DNA was stained with DAPI. Preliminary observations suggest that cells with multiple centrosomes are able to generate extra cilia.
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Affiliation(s)
- Kathyayini V Divi
- Carcinogen-DNA Interactions Section, LCBG, CCR, NIH, Bethesda, Maryland
| | - Yvona Ward
- Cell and Cancer Biology Branch, National Cancer Institute, NIH, Bethesda, Maryland
| | - Miriam C Poirier
- Carcinogen-DNA Interactions Section, LCBG, CCR, NIH, Bethesda, Maryland
| | - Ofelia A Olivero
- Carcinogen-DNA Interactions Section, LCBG, CCR, NIH, Bethesda, Maryland
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14
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Khoo NKH, Cantu-Medellin N, St Croix C, Kelley EE. In Vivo Immuno-Spin Trapping: Imaging the Footprints of Oxidative Stress. CURRENT PROTOCOLS IN CYTOMETRY 2015; 74:12.42.1-12.42.11. [PMID: 26423693 PMCID: PMC4889111 DOI: 10.1002/0471142956.cy1242s74] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A plethora of disease processes are associated with elevated reactive species formation and allied reactions with biomolecules that alter cell signaling, induce overt damage, and promote dysfunction of tissues. Unfortunately, effective detection of reactive species in tissues is wrought with issues that significantly limit capacity for validating species identity, establishing accurate concentrations, and identifying anatomic sites of production. These shortcomings reveal the pressing need for new approaches to more precisely assess reactive species generation in vivo. Herein, we describe an in vivo immuno-spin trapping method for indirectly assessing oxidant levels by detecting free radicals resulting from reaction of oxidants with biomolecules to form stable, immunologically detectable nitrone-biomolecular adducts. This process couples the reactivity and sensitivity of an electron paramagnetic resonance spin trap with the resolution of confocal imaging to visualize the extent of cell and tissue oxidation and anatomic sites of production by detecting resultant free radical formation.
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Affiliation(s)
- Nicholas K H Khoo
- Departments of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | | | - Claudette St Croix
- Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Eric E Kelley
- Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Anesthesiology, University of Pittsburgh, Pittsburgh, Pennsylvania
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15
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Taura J, Fernández-Dueñas V, Ciruela F. Visualizing G Protein-Coupled Receptor-Receptor Interactions in Brain Using Proximity Ligation In Situ Assay. ACTA ACUST UNITED AC 2015; 67:17.17.1-17.17.16. [PMID: 26061241 DOI: 10.1002/0471143030.cb1717s67] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
G protein-coupled receptors (GPCRs) constitute the largest family of plasma membrane receptors, thus representing the more investigated drug targets in the design of new therapeutic strategies. The existence of receptor-receptor interactions has revolutionized the field, since GPCR oligomerization might confer new intervention opportunities in pharmacotherapy. However, demonstrating the existence of such receptor-receptor interactions in native tissue has been a bottleneck in GPCR pharmacology. Here, we discuss an experimental approach, the proximity ligation in situ assay (P-LISA), which provides enough sensitivity to evaluate a receptor's close proximity within a named GPCR oligomer. Indeed, we provide a detailed step-by-step protocol for P-LISA experiments visualizing receptor-receptor interactions in brain slices. Additionally, we provide instructions for slide observation, data acquisition and quantification. Finally, we also discuss these critical aspects determining the success of the technique, namely the fixation process and the validation of the primary antibodies used. Overall, the P-LISA is a powerful and straightforward technique to visualize receptor-receptor interactions when performed under optimal conditions.
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Affiliation(s)
- Jaume Taura
- Unitat de Farmacologia, Departament Patologia i Terapèutica Experimental, Facultat de Medicina, IDIBELL-Universitat de Barcelona, Barcelona, Spain
| | - Víctor Fernández-Dueñas
- Unitat de Farmacologia, Departament Patologia i Terapèutica Experimental, Facultat de Medicina, IDIBELL-Universitat de Barcelona, Barcelona, Spain
| | - Francisco Ciruela
- Unitat de Farmacologia, Departament Patologia i Terapèutica Experimental, Facultat de Medicina, IDIBELL-Universitat de Barcelona, Barcelona, Spain.,Department of Physiology, Faculty of Sciences, University of Ghent, Ghent, Belgium
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Schmidt RL, Sheeley SL. Mating and memory: an educational primer for use with "epigenetic control of learning and memory in Drosophila by Tip60 HAT action". Genetics 2015; 200:21-8. [PMID: 25953906 PMCID: PMC4423364 DOI: 10.1534/genetics.115.176313] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 03/12/2015] [Indexed: 01/21/2023] Open
Abstract
An article by Xu et al. in the December 2014 issue of GENETICS can be used to illustrate epigenetic modification of gene expression, reverse genetic manipulation, genetic/epigenetic influence on behavioral studies, and studies using the Drosophila model organism applied to human disease. This Primer provides background information; technical explanations of genetic, biochemical, and behavioral approaches from the study; and an example of an approach for classroom use with discussion questions to aid in student comprehension of the research article.
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Affiliation(s)
- Rebecca L Schmidt
- Department of Biology and Chemistry, Upper Iowa University, Fayette, Iowa 52132
| | - Sara L Sheeley
- Department of Biology and Chemistry, Upper Iowa University, Fayette, Iowa 52132
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Fogarty MJ, Hammond LA, Kanjhan R, Bellingham MC, Noakes PG. A method for the three-dimensional reconstruction of Neurobiotin™-filled neurons and the location of their synaptic inputs. Front Neural Circuits 2013; 7:153. [PMID: 24101895 PMCID: PMC3787200 DOI: 10.3389/fncir.2013.00153] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 09/12/2013] [Indexed: 12/15/2022] Open
Abstract
Here, we describe a robust method for mapping the number and type of neuro-chemically distinct synaptic inputs that a single reconstructed neuron receives. We have used individual hypoglossal motor neurons filled with Neurobiotin by semi-loose seal electroporation in thick brainstem slices. These filled motor neurons were then processed for excitatory and inhibitory synaptic inputs, using immunohistochemical-labeling procedures. For excitatory synapses, we used anti-VGLUT2 to locate glutamatergic pre-synaptic terminals and anti-PSD-95 to locate post-synaptic specializations on and within the surface of these filled motor neurons. For inhibitory synapses, we used anti-VGAT to locate GABAergic pre-synaptic terminals and anti-GABA-A receptor subunit α1 to locate the post-synaptic domain. The Neurobiotin-filled and immuno-labeled motor neuron was then processed for optical sectioning using confocal microscopy. The morphology of the motor neuron including its dendritic tree and the distribution of excitatory and inhibitory synapses were then determined by three-dimensional reconstruction using IMARIS software (Bitplane). Using surface rendering, fluorescence thresholding, and masking of unwanted immuno-labeling, tools found in IMARIS, we were able to obtain an accurate 3D structure of an individual neuron including the number and location of its glutamatergic and GABAergic synaptic inputs. The power of this method allows for a rapid morphological confirmation of the post-synaptic responses recorded by patch-clamp prior to Neurobiotin filling. Finally, we show that this method can be adapted to super-resolution microscopy techniques, which will enhance its applicability to the study of neural circuits at the level of synapses.
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Affiliation(s)
- Matthew J Fogarty
- School of Biomedical Sciences, The University of Queensland Brisbane, QLD, Australia
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