1
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Nienhaus K, Nienhaus GU. Mechanistic Understanding of Protein Corona Formation around Nanoparticles: Old Puzzles and New Insights. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023:e2301663. [PMID: 37010040 DOI: 10.1002/smll.202301663] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 03/14/2023] [Indexed: 06/19/2023]
Abstract
Although a wide variety of nanoparticles (NPs) have been engineered for use as disease markers or drug delivery agents, the number of nanomedicines in clinical use has hitherto remained small. A key obstacle in nanomedicine development is the lack of a deep mechanistic understanding of NP interactions in the bio-environment. Here, the focus is on the biomolecular adsorption layer (protein corona), which quickly enshrouds a pristine NP exposed to a biofluid and modifies the way the NP interacts with the bio-environment. After a brief introduction of NPs for nanomedicine, proteins, and their mutual interactions, research aimed at addressing fundamental properties of the protein corona, specifically its mono-/multilayer structure, reversibility and irreversibility, time dependence, as well as its role in NP agglomeration, is critically reviewed. It becomes quite evident that the knowledge of the protein corona is still fragmented, and conflicting results on fundamental issues call for further mechanistic studies. The article concludes with a discussion of future research directions that should be taken to advance the understanding of the protein corona around NPs. This knowledge will provide NP developers with the predictive power to account for these interactions in the design of efficacious nanomedicines.
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Affiliation(s)
- Karin Nienhaus
- Institute of Applied Physics, Karlsruhe Institute of Technology, 76049, Karlsruhe, Germany
| | - Gerd Ulrich Nienhaus
- Institute of Applied Physics, Karlsruhe Institute of Technology, 76049, Karlsruhe, Germany
- Institute of Nanotechnology, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany
- Institute of Biological and Chemical Systems, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
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2
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Fulton MD, Najahi-Missaoui W. Liposomes in Cancer Therapy: How Did We Start and Where Are We Now. Int J Mol Sci 2023; 24:ijms24076615. [PMID: 37047585 PMCID: PMC10095497 DOI: 10.3390/ijms24076615] [Citation(s) in RCA: 41] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/28/2023] [Accepted: 03/29/2023] [Indexed: 04/05/2023] Open
Abstract
Since their first discovery in the 1960s by Alec Bangham, liposomes have been shown to be effective drug delivery systems for treating various cancers. Several liposome-based formulations received approval by the U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA), with many others in clinical trials. Liposomes have several advantages, including improved pharmacokinetic properties of the encapsulated drug, reduced systemic toxicity, extended circulation time, and targeted disposition in tumor sites due to the enhanced permeability and retention (EPR) mechanism. However, it is worth noting that despite their efficacy in treating various cancers, liposomes still have some potential toxicity and lack specific targeting and disposition. This explains, in part, why their translation into the clinic has progressed only incrementally, which poses the need for more research to focus on addressing such translational limitations. This review summarizes the main properties of liposomes, their current status in cancer therapy, and their limitations and challenges to achieving maximal therapeutic efficacy.
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Affiliation(s)
- Melody D. Fulton
- Department of Chemistry, College of Arts and Sciences, Washington State University, Pullman, WA 99164, USA
| | - Wided Najahi-Missaoui
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA 30602, USA
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3
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Yan T, Wang X, Liu S, Fan D, Xu X, Zeng Q, Xie H, Yang X, Zhu S, Ma X, Yuan Z, Chen X. Confocal Laser Scanning Microscopy Based on a Silicon Photomultiplier for Multicolor In Vivo Imaging in Near-Infrared Regions I and II. SMALL METHODS 2022; 6:e2201105. [PMID: 36351753 DOI: 10.1002/smtd.202201105] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 10/12/2022] [Indexed: 06/16/2023]
Abstract
Confocal laser scanning microscopy (CLSM) is expected to exhibit a better imaging performance in the second near-infrared (NIR-II) windows with weak tissue scattering and autofluorescence. However, the indium gallium arsenide (InGaAs) detectors currently used for imaging in the NIR-II region are prohibitively expensive, hampering its extensive biomedical applications. In this study, a novel NIR-II CLSM system is developed by using the inexpensive silicon photomultiplier (SiPM) that can perform the multicolor biological imaging in vivo. Using IR-780 iodide as the contrast agent, the NIR-II imaging capability of constructed CLSM is inspected, demonstrating a spatial resolution of 1.68 µm (close to the diffraction limit) and a fluorophore detection sensitivity as low as 100 nm. In particular, it is discovered that the multicolor imaging performance in both NIR-I and NIR-II windows is comparable to those from multialkali and InGaAs photomultiplier tubes. In addition, 3D NIR-II CLSM is also conducted for in vivo imaging of the vascular structure in mouse ear and subcutaneous tumors. To the best of authors' knowledge, this is the first time that a low-cost detector based on a SiPM has been used for microscopic imaging of trailing fluorescence signals in the NIR-II region of an NIR fluorescent probe.
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Affiliation(s)
- Tianyu Yan
- School of Life Science and Technology, Xidian University & Engineering Research Center of Molecular and Neuro Imaging, Ministry of Education, Xi'an, Shaanxi, 710126, China
- Xi'an Key Laboratory of Intelligent Sensing and Regulation of trans-Scale Life Information & International Joint Research Center for Advanced Medical Imaging and Intelligent Diagnosis and Treatment, School of Life Science and Technology, Xidian University, Xi'an, Shaanxi, 710126, China
| | - Xinyu Wang
- School of Life Science and Technology, Xidian University & Engineering Research Center of Molecular and Neuro Imaging, Ministry of Education, Xi'an, Shaanxi, 710126, China
- Xi'an Key Laboratory of Intelligent Sensing and Regulation of trans-Scale Life Information & International Joint Research Center for Advanced Medical Imaging and Intelligent Diagnosis and Treatment, School of Life Science and Technology, Xidian University, Xi'an, Shaanxi, 710126, China
| | - Siting Liu
- School of Life Science and Technology, Xidian University & Engineering Research Center of Molecular and Neuro Imaging, Ministry of Education, Xi'an, Shaanxi, 710126, China
- Xi'an Key Laboratory of Intelligent Sensing and Regulation of trans-Scale Life Information & International Joint Research Center for Advanced Medical Imaging and Intelligent Diagnosis and Treatment, School of Life Science and Technology, Xidian University, Xi'an, Shaanxi, 710126, China
| | - Dawei Fan
- School of Life Science and Technology, Xidian University & Engineering Research Center of Molecular and Neuro Imaging, Ministry of Education, Xi'an, Shaanxi, 710126, China
- Xi'an Key Laboratory of Intelligent Sensing and Regulation of trans-Scale Life Information & International Joint Research Center for Advanced Medical Imaging and Intelligent Diagnosis and Treatment, School of Life Science and Technology, Xidian University, Xi'an, Shaanxi, 710126, China
| | - Xinyi Xu
- School of Life Science and Technology, Xidian University & Engineering Research Center of Molecular and Neuro Imaging, Ministry of Education, Xi'an, Shaanxi, 710126, China
- Xi'an Key Laboratory of Intelligent Sensing and Regulation of trans-Scale Life Information & International Joint Research Center for Advanced Medical Imaging and Intelligent Diagnosis and Treatment, School of Life Science and Technology, Xidian University, Xi'an, Shaanxi, 710126, China
| | - Qi Zeng
- School of Life Science and Technology, Xidian University & Engineering Research Center of Molecular and Neuro Imaging, Ministry of Education, Xi'an, Shaanxi, 710126, China
- Xi'an Key Laboratory of Intelligent Sensing and Regulation of trans-Scale Life Information & International Joint Research Center for Advanced Medical Imaging and Intelligent Diagnosis and Treatment, School of Life Science and Technology, Xidian University, Xi'an, Shaanxi, 710126, China
| | - Hui Xie
- School of Life Science and Technology, Xidian University & Engineering Research Center of Molecular and Neuro Imaging, Ministry of Education, Xi'an, Shaanxi, 710126, China
- Xi'an Key Laboratory of Intelligent Sensing and Regulation of trans-Scale Life Information & International Joint Research Center for Advanced Medical Imaging and Intelligent Diagnosis and Treatment, School of Life Science and Technology, Xidian University, Xi'an, Shaanxi, 710126, China
| | - Xiaoli Yang
- School of Control Science and Engineering, Shandong University, Jinan, Shandong, 250061, China
| | - Shouping Zhu
- School of Life Science and Technology, Xidian University & Engineering Research Center of Molecular and Neuro Imaging, Ministry of Education, Xi'an, Shaanxi, 710126, China
- Xi'an Key Laboratory of Intelligent Sensing and Regulation of trans-Scale Life Information & International Joint Research Center for Advanced Medical Imaging and Intelligent Diagnosis and Treatment, School of Life Science and Technology, Xidian University, Xi'an, Shaanxi, 710126, China
- Innovation Center for Advanced Medical Imaging and Intelligent Medicine, Guangzhou Institute of Technology, Xidian University, Guangzhou, Guangdong, 51055, China
| | - Xiaopeng Ma
- School of Control Science and Engineering, Shandong University, Jinan, Shandong, 250061, China
| | - Zhen Yuan
- Faculty of Health Sciences, University of Macau, Macau, 999078, China
| | - Xueli Chen
- School of Life Science and Technology, Xidian University & Engineering Research Center of Molecular and Neuro Imaging, Ministry of Education, Xi'an, Shaanxi, 710126, China
- Xi'an Key Laboratory of Intelligent Sensing and Regulation of trans-Scale Life Information & International Joint Research Center for Advanced Medical Imaging and Intelligent Diagnosis and Treatment, School of Life Science and Technology, Xidian University, Xi'an, Shaanxi, 710126, China
- Innovation Center for Advanced Medical Imaging and Intelligent Medicine, Guangzhou Institute of Technology, Xidian University, Guangzhou, Guangdong, 51055, China
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4
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Ambrosi G, Voloshanenko O, Eckert AF, Kranz D, Nienhaus GU, Boutros M. Allele-specific endogenous tagging and quantitative analysis of β-catenin in colorectal cancer cells. eLife 2022; 11:64498. [PMID: 35014953 PMCID: PMC8752093 DOI: 10.7554/elife.64498] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 12/16/2021] [Indexed: 12/16/2022] Open
Abstract
Wnt signaling plays important roles in development, homeostasis, and tumorigenesis. Mutations in β-catenin that activate Wnt signaling have been found in colorectal and hepatocellular carcinomas. However, the dynamics of wild-type and mutant forms of β-catenin are not fully understood. Here, we genome-engineered fluorescently tagged alleles of endogenous β-catenin in a colorectal cancer cell line. Wild-type and oncogenic mutant alleles were tagged with different fluorescent proteins, enabling the analysis of both variants in the same cell. We analyzed the properties of both β-catenin alleles using immunoprecipitation, immunofluorescence, and fluorescence correlation spectroscopy approaches, revealing distinctly different biophysical properties. In addition, activation of Wnt signaling by treatment with a GSK3β inhibitor or a truncating APC mutation modulated the wild-type allele to mimic the properties of the mutant β-catenin allele. The one-step tagging strategy demonstrates how genome engineering can be employed for the parallel functional analysis of different genetic variants.
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Affiliation(s)
- Giulia Ambrosi
- German Cancer Research Center (DKFZ), Division of Signaling and Functional Genomics and Heidelberg University, BioQuant and Medical Faculty Mannheim, Heidelberg, Germany
| | - Oksana Voloshanenko
- German Cancer Research Center (DKFZ), Division of Signaling and Functional Genomics and Heidelberg University, BioQuant and Medical Faculty Mannheim, Heidelberg, Germany
| | - Antonia F Eckert
- Institute of Applied Physics, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Dominique Kranz
- German Cancer Research Center (DKFZ), Division of Signaling and Functional Genomics and Heidelberg University, BioQuant and Medical Faculty Mannheim, Heidelberg, Germany
| | - G Ulrich Nienhaus
- Institute of Applied Physics, Karlsruhe Institute of Technology, Karlsruhe, Germany.,Institute of Nanotechnology, Karlsruhe Institute of Technology, Karlsruhe, Germany.,Institute of Biological and Chemical Systems, Karlsruhe Institute of Technology, Karlsruhe, Germany.,Department of Physics, University of Illinois at Urbana-Champaign, Urbana, United States
| | - Michael Boutros
- German Cancer Research Center (DKFZ), Division of Signaling and Functional Genomics and Heidelberg University, BioQuant and Medical Faculty Mannheim, Heidelberg, Germany
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5
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Junaid M, Wang J. Interaction of nanoplastics with extracellular polymeric substances (EPS) in the aquatic environment: A special reference to eco-corona formation and associated impacts. WATER RESEARCH 2021; 201:117319. [PMID: 34130084 DOI: 10.1016/j.watres.2021.117319] [Citation(s) in RCA: 81] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 05/16/2021] [Accepted: 05/28/2021] [Indexed: 06/12/2023]
Abstract
Nanoplastics (NPs) are plastic particles with sizes ranging between 1 and 1000 nm, exhibiting exceptional qualities such as large surface area, lightweight, durability; therefore, are widely used in cosmetics, paints, electronics, etc. NPs are inevitability released into the aquatic environment where they tend to interact with both, the extracellular polymeric substances (EPS) and other fractions of natural organic matter (NOM), respectively secreted by organisms (e.g., DNA, proteins, and carbohydrates) and degradation byproducts of organic materials (e.g., humic acid and fulvic acid) fluxed into the water bodies. These biomolecules robustly encapsulate NPs to develop an eco-corona layer that alters not only the physicochemical properties but also the fate, bioreactivity, and ecological impacts of NPs. Therefore, this review summarized the documented studies highlighting the eco-corona formation on NPs and associated ecological implications in the aquatic environment. After presenting the precise background information on the occurrence of NPs and EPS in the aquatic environment, we demonstrated the basic difference between eco-corona and bio-corona formation. The reviewed studies showed that the eco-corona formed on NPs have varying sizes and composition, mainly depending on the properties of parent biomolecules, characteristics of NPs, and physicochemical parameters of the aquatic environment. Further, the potential methods for characterization and quantification of eco-corona and its composition have been also highlighted. Moreover, the ecological implications (both toxic and non-toxic) of eco-corona formation on NPs in marine and freshwater environments have been also summarized. Last but not the least, challenges and future research directions are also given, e.g., conducting field studies on eco-corona formation in the aquatic environment, optimizing methods for its characterization and quantification, and considering eco-corona concept in the future toxicity studies on NPs. Finally, understanding eco-corona formation will be critical to unveil the complex NP interactions occurring in natural aquatic systems.
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Affiliation(s)
- Muhammad Junaid
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou 510641, China
| | - Jun Wang
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou 510641, China; Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, China.
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6
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Gao P, Nienhaus GU. Axial line-scanning stimulated emission depletion fluorescence correlation spectroscopy. OPTICS LETTERS 2021; 46:2184-2187. [PMID: 33929450 DOI: 10.1364/ol.420765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 04/01/2021] [Indexed: 06/12/2023]
Abstract
Investigating the dynamics and interactions of biomolecules within or attached to membranes of living cells is crucial for understanding biology at the molecular level. In this pursuit, classical, diffraction-limited optical fluorescence microscopy is widely used, but it faces limitations due to (1) the heterogeneity of biomembranes on the nanoscale and (2) the intrinsic motion of membranes with respect to the focus. Here we introduce a new confocal microscopy-based fluctuation spectroscopy technique aimed at alleviating these two problems, called axial line-scanning stimulated emission depletion fluorescence correlation spectroscopy (axial ls-STED-FCS). Axial line scanning by means of a tunable acoustic gradient index of refraction lens provides a time resolution of a few microseconds, which is more than two orders of magnitude greater than that of conventional, lateral line-scanning fluorescence correlation spectroscopy (typically around 1 ms). Using STED excitation, the observation area on the membrane can be reduced 10-100 fold, resulting in sub-diffraction spatial resolution and the ability to study samples with densely labeled membranes. Due to these attractive properties, we expect that the axial ls-STED-FCS will find wide application, especially in the biomolecular sciences.
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7
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Brownian motion-based nanoparticle sizing-A powerful approach for in situ analysis of nanoparticle-protein interactions. Biointerphases 2020; 15:061201. [PMID: 33356335 DOI: 10.1116/6.0000438] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
A key hurdle toward effective application of nanoparticles (NPs) in biomedicine is still the incomplete understanding of the biomolecular adsorption layer, the so-called protein corona, which inevitably forms around NPs when they are immersed in a biofluid. NP sizing techniques via the analysis of Brownian motions offer a powerful way to measure the thickness of the protein corona in situ. Here, the fundamentals of three techniques, dynamic light scattering, fluorescence correlation spectroscopy, and nanoparticle tracking analysis are briefly summarized. Then, experimental procedures for the determination of binding curves are presented in a tutorial fashion. Nanoparticle sizing experiments are illustrated with a selection of recent results on the interactions of transferrin with hydrophilic and hydrophobic polystyrene nanoparticles, and key insights gained from this work are discussed.
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8
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Eckert AF, Gao P, Wesslowski J, Wang X, Rath J, Nienhaus K, Davidson G, Nienhaus GU. Measuring ligand-cell surface receptor affinities with axial line-scanning fluorescence correlation spectroscopy. eLife 2020; 9:55286. [PMID: 32441251 PMCID: PMC7289602 DOI: 10.7554/elife.55286] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 05/21/2020] [Indexed: 12/12/2022] Open
Abstract
Development and homeostasis of multicellular organisms is largely controlled by complex cell-cell signaling networks that rely on specific binding of secreted ligands to cell surface receptors. The Wnt signaling network, as an example, involves multiple ligands and receptors to elicit specific cellular responses. To understand the mechanisms of such a network, ligand-receptor interactions should be characterized quantitatively, ideally in live cells or tissues. Such measurements are possible using fluorescence microscopy yet challenging due to sample movement, low signal-to-background ratio and photobleaching. Here, we present a robust approach based on fluorescence correlation spectroscopy with ultra-high speed axial line scanning, yielding precise equilibrium dissociation coefficients of interactions in the Wnt signaling pathway. Using CRISPR/Cas9 editing to endogenously tag receptors with fluorescent proteins, we demonstrate that the method delivers precise results even with low, near-native amounts of receptors.
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Affiliation(s)
| | - Peng Gao
- Institute of Applied Physics, Karlsruhe Institute of Technology, Karlsruhe, Germany.,Institute of Nanotechnology, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Janine Wesslowski
- Institute of Biological and Chemical Systems, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Xianxian Wang
- Institute of Biological and Chemical Systems, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Jasmijn Rath
- Institute of Applied Physics, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Karin Nienhaus
- Institute of Applied Physics, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Gary Davidson
- Institute of Biological and Chemical Systems, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Gerd Ulrich Nienhaus
- Institute of Applied Physics, Karlsruhe Institute of Technology, Karlsruhe, Germany.,Institute of Nanotechnology, Karlsruhe Institute of Technology, Karlsruhe, Germany.,Institute of Biological and Chemical Systems, Karlsruhe Institute of Technology, Karlsruhe, Germany.,Department of Physics, University of Illinois at Urbana-Champaign, Urbana, United States
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9
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Chen Q, Shao X, Hao M, Fang H, Guan R, Tian Z, Li M, Wang C, Ji L, Chao H, Guan JL, Diao J. Quantitative analysis of interactive behavior of mitochondria and lysosomes using structured illumination microscopy. Biomaterials 2020; 250:120059. [PMID: 32339858 DOI: 10.1016/j.biomaterials.2020.120059] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 04/07/2020] [Accepted: 04/17/2020] [Indexed: 12/24/2022]
Abstract
Super-resolution optical microscopy has extended the spatial resolution of cell biology from the cellular level to the nanoscale, enabling the observation of the interactive behavior of single mitochondria and lysosomes. Quantitative parametrization of interactions between mitochondria and lysosomes under super-resolution optical microscopy, however, is currently unavailable, which has severely limited our understanding of the molecular machinery underlying mitochondrial functionality. Here, we introduce an M-value to quantitatively investigate mitochondria and lysosome contact (MLC) and mitophagy under structured illumination microscopy. We found that the M-value for an MLC is typically less than 0.4, whereas in mitophagy it ranges from 0.5 to 1.0. This system permits further investigation of the detailed molecular mechanism governing the interactive behavior of mitochondria and lysosomes.
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Affiliation(s)
- Qixin Chen
- Department of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA; Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan, 646000, China
| | - Xintian Shao
- Department of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA; Shandong Academy of Pharmaceutical Science, Key Laboratory of Biopharmaceuticals, Engineering Laboratory of Polysaccharide Drugs, National-Local Joint Engineering Laboratory of Polysaccharide Drugs, Jinan, 250101, China
| | - Mingang Hao
- Department of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Hongbao Fang
- Department of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Ruilin Guan
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Zhiqi Tian
- Department of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Miaoling Li
- Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan, 646000, China
| | - Chenran Wang
- Department of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Liangnian Ji
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Hui Chao
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, China.
| | - Jun-Lin Guan
- Department of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA.
| | - Jiajie Diao
- Department of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA.
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10
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Klett J, Gómez-Casero E, Méndez-Pertuz M, Urbano-Cuadrado M, Megias D, Blasco MA, Martínez S, Pastor J, Blanco-Aparicio C. Screening protocol for the identification of modulators by immunofluorescent cell-based assay. Chem Biol Drug Des 2019; 95:66-78. [PMID: 31469231 DOI: 10.1111/cbdd.13616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 06/05/2019] [Accepted: 08/11/2019] [Indexed: 11/30/2022]
Abstract
High-throughput assays are a common strategy for the identification of compounds able to modulate a certain cellular activity. Here, we show an automatized analysis platform for the quantification of nuclear foci as inhibitory effect of compounds on a target protein labeled by fluorescent antibodies. Our experience led us to a fast analysis platform that combines cell-based assays, high-content screening, and confocal microscopy, with an automatic and user-friendly statistical analysis of plate-based assays including positive and negative controls, able to identify inhibitory effect of compounds tested together with the Z-prime and Window of individual plate-based assays to assess the reliability of the results. The platform integrates a web-based tool implemented in Pipeline Pilot and R, and allows computing the inhibition values of different parameters obtained from the high-content screening and confocal microscopy analysis. This facilitates the exploration of the results using the different parameters, providing information at different levels as the number of foci observed, the sum of intensity of foci, area of foci, etc, the detection and filtering of outliers over the assay plate, and finally providing a set of statistics of the parameters studied together with a set of plots that we believe significantly helps to the interpretation of the assay results.
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Affiliation(s)
- Javier Klett
- Experimental Therapeutics Program, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Elena Gómez-Casero
- Experimental Therapeutics Program, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Marinela Méndez-Pertuz
- Telomeres and Telomerase Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Manuel Urbano-Cuadrado
- Experimental Therapeutics Program, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Diego Megias
- Microscopy Unit, Biotechnology Program, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - María A Blasco
- Telomeres and Telomerase Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Sonia Martínez
- Experimental Therapeutics Program, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Joaquín Pastor
- Experimental Therapeutics Program, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Carmen Blanco-Aparicio
- Experimental Therapeutics Program, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
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11
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12
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Gao X, Gao P, Prunsche B, Nienhaus K, Nienhaus GU. Pulsed interleaved excitation-based line-scanning spatial correlation spectroscopy (PIE-lsSCS). Sci Rep 2018; 8:16722. [PMID: 30425308 PMCID: PMC6233157 DOI: 10.1038/s41598-018-35146-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 10/31/2018] [Indexed: 11/09/2022] Open
Abstract
We report pulsed interleaved excitation (PIE) based line-scanning spatial correlation spectroscopy (PIE-lsSCS), a quantitative fluorescence microscopy method for the study of dynamics in free-standing lipid bilayer membranes. Using a confocal microscope, we scan multiple lines perpendicularly through the membrane, each one laterally displaced from the previous one by several ten nanometers. Scanning through the membrane enables us to eliminate intensity fluctuations due to membrane displacements with respect to the observation volume. The diffusion of fluorescent molecules within the membrane is quantified by spatial correlation analysis, based on the fixed lag times between successive line scans. PIE affords dual-color excitation within a single line scan and avoids channel crosstalk. PIE-lsSCS data are acquired from a larger membrane region so that sampling is more efficient. Moreover, the local photon flux is reduced compared with single-point experiments, resulting in a smaller fraction of photobleached molecules for identical exposure times. This is helpful for precise measurements on live cells and tissues. We have evaluated the method with experiments on fluorescently labeled giant unilamellar vesicles (GUVs) and membrane-stained live cells.
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Affiliation(s)
- Xiang Gao
- Institute of Applied Physics, Karlsruhe Institute of Technology, 76128, Karlsruhe, Germany
| | - Peng Gao
- Institute of Applied Physics, Karlsruhe Institute of Technology, 76128, Karlsruhe, Germany
- Institute of Nanotechnology, Karlsruhe Institute of Technology, 76344, Eggenstein-Leopoldshafen, Germany
| | - Benedikt Prunsche
- Institute of Applied Physics, Karlsruhe Institute of Technology, 76128, Karlsruhe, Germany
| | - Karin Nienhaus
- Institute of Applied Physics, Karlsruhe Institute of Technology, 76128, Karlsruhe, Germany
| | - Gerd Ulrich Nienhaus
- Institute of Applied Physics, Karlsruhe Institute of Technology, 76128, Karlsruhe, Germany.
- Institute of Nanotechnology, Karlsruhe Institute of Technology, 76344, Eggenstein-Leopoldshafen, Germany.
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, 76344, Eggenstein-Leopoldshafen, Germany.
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois, 61801, USA.
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13
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Beloqui A, Kobitski AY, Nienhaus GU, Delaittre G. A simple route to highly active single-enzyme nanogels. Chem Sci 2018; 9:1006-1013. [PMID: 29675147 PMCID: PMC5883864 DOI: 10.1039/c7sc04438k] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 11/30/2017] [Indexed: 11/25/2022] Open
Abstract
We have established a simple one-step synthesis of single-enzyme nanogels (SENs), i.e., nanobiocatalysts consisting of an enzyme molecule embedded in a hydrophilic, polymeric crosslinked nanostructure, as a most attractive approach to enhance the stability of enzymes. In contrast to earlier protocols, we demonstrate here that the addition of a small amount of sucrose makes the nanogel formation equally effective as earlier two-step protocols requiring enzyme pre-modification. This provides the dual advantage of skipping a synthetic step and preserving the surface chemistry of the enzymes, hence their native structure. Enzymes encapsulated in this way exhibit a high catalytic activity, similar to that of the free enzymes, in a markedly widened pH range. With our method, the thickness of the hydrogel layer can be finely tuned by careful adjustment of reaction parameters. This is most important because the shell thickness strongly affects both enzyme activity and stability, as we observe for a wide selection of proteins. Finally, a single-molecule analysis by means of two-color confocal fluorescence coincidence analysis confirms that our encapsulation method is highly efficient and suppresses the occurrence of nanoparticles lacking an enzyme molecule. The proposed method is therefore highly attractive for biocatalysis applications, ensuring a high activity and stability of the enzymes.
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Affiliation(s)
- Ana Beloqui
- Institute of Toxicology and Genetics , Karlsruhe Institute of Technology (KIT) , Hermann-von-Helmholtz-Platz 1 , 76344 Eggenstein-Leopoldshafen , Germany . ;
- Preparative Macromolecular Chemistry , Institute for Technical Chemistry and Polymer Chemistry , Karlsruhe Institute of Technology (KIT) , Engesserstrasse 15 , 76131 Karlsruhe , Germany
| | - Andrei Yu Kobitski
- Institute of Applied Physics , Karlsruhe Institute of Technology (KIT) , Wolfgang-Gaede-Strasse 1 , 76131 Karlsruhe , Germany
| | - Gerd Ulrich Nienhaus
- Institute of Toxicology and Genetics , Karlsruhe Institute of Technology (KIT) , Hermann-von-Helmholtz-Platz 1 , 76344 Eggenstein-Leopoldshafen , Germany . ;
- Institute of Applied Physics , Karlsruhe Institute of Technology (KIT) , Wolfgang-Gaede-Strasse 1 , 76131 Karlsruhe , Germany
- Institute of Nanotechnology , Karlsruhe Institute of Technology (KIT) , Hermann-von-Helmholtz-Platz 1 , 76344 Eggenstein-Leopoldshafen , Germany
- Department of Physics , University of Illinois at Urbana-Champaign , Urbana , Illinois 61801 , USA
| | - Guillaume Delaittre
- Institute of Toxicology and Genetics , Karlsruhe Institute of Technology (KIT) , Hermann-von-Helmholtz-Platz 1 , 76344 Eggenstein-Leopoldshafen , Germany . ;
- Preparative Macromolecular Chemistry , Institute for Technical Chemistry and Polymer Chemistry , Karlsruhe Institute of Technology (KIT) , Engesserstrasse 15 , 76131 Karlsruhe , Germany
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14
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Wang H, Lin Y, Nienhaus K, Nienhaus GU. The protein corona on nanoparticles as viewed from a nanoparticle‐sizing perspective. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2017; 10:e1500. [DOI: 10.1002/wnan.1500] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 08/28/2017] [Accepted: 09/18/2017] [Indexed: 01/02/2023]
Affiliation(s)
- Haixia Wang
- Institute of Applied PhysicsKarlsruhe Institute of TechnologyKarlsruheGermany
| | - Youhui Lin
- Institute of Applied PhysicsKarlsruhe Institute of TechnologyKarlsruheGermany
- Institute of NanotechnologyKarlsruhe Institute of TechnologyEggenstein‐LeopoldshafenGermany
| | - Karin Nienhaus
- Institute of Applied PhysicsKarlsruhe Institute of TechnologyKarlsruheGermany
| | - G. Ulrich Nienhaus
- Institute of Applied PhysicsKarlsruhe Institute of TechnologyKarlsruheGermany
- Institute of NanotechnologyKarlsruhe Institute of TechnologyEggenstein‐LeopoldshafenGermany
- Institute of Toxicology and GeneticsKarlsruhe Institute of TechnologyEggenstein‐LeopoldshafenGermany
- Department of PhysicsUniversity of Illinois at Urbana‐ChampaignUrbanaILUSA
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15
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Shang L, Nienhaus GU. In Situ Characterization of Protein Adsorption onto Nanoparticles by Fluorescence Correlation Spectroscopy. Acc Chem Res 2017; 50:387-395. [PMID: 28145686 DOI: 10.1021/acs.accounts.6b00579] [Citation(s) in RCA: 113] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Nanotechnology holds great promise for applications in many fields including biology and medicine. Unfortunately, the processes occurring at the interface between nanomaterials and living systems are exceedingly complex and not yet well understood, which has significantly hampered the realization of many nanobiotechnology applications. Whenever nanoparticles (NPs) are incorporated by a living organism, a protein adsorption layer, also known as the "protein corona", forms on the NP surface. Accordingly, living organisms interact with protein-coated rather than bare NPs, and their biological responses depend on the nature of the protein corona. In recent years, a wide variety of biophysical techniques have been employed to elucidate mechanistic aspects of NP-protein interactions. In most studies, NPs are immersed in protein or biofluid (e.g., blood serum) solutions and then separated from the liquid for analysis. Because this approach may modify the composition and structure of the protein corona, our group has pioneered the use of fluorescence correlation spectroscopy (FCS) as an in situ technique, capable of examining NP-protein interactions while the NPs are suspended in biological fluids. FCS allows us to measure, with subnanometer precision and as a function of protein concentration, the increase in hydrodynamic radius of the NPs due to protein adsorption. This Account aims at reviewing recent progress in the exploration of NP-protein interactions by using FCS. In vitro FCS studies of the adsorption of important serum proteins onto water-solubilized luminescent NPs always showed a stepwise increase of the NP radius upon protein binding in the form of a binding isotherm, regardless of the type of NP and its specific surface functionalization. This observation indicates formation of a protein monolayer on the NP. Structure-based calculations of protein surface potentials revealed that positively charged patches on the proteins interact electrostatically with negatively charged NP surfaces, and the observed protein layer thickness always matched the known molecular dimensions of the proteins binding in certain orientations. Temperature and NP surface functionalization have also been identified as important parameters controlling protein corona formation. Notably, while the corona formed from a single type of serum protein was reversible, protein adsorption from complex biological media such as blood serum was entirely irreversible. These quantitative in vitro studies are of great relevance to the bio-nano community and especially to researchers developing engineered nanomaterials for biological and biomedical applications. Future efforts will be directed toward elucidating kinetic aspects of protein corona formation and the detailed structure of the adsorbed proteins at the molecular level. To better appreciate the biological responses triggered by NP exposure, more efforts will be devoted to the exploration of the biomolecular corona as it forms on NPs in contact with living cells, tissues, and even entire model organisms. These studies are challenging when performed in a well-controlled and quantitative fashion and rely on the availability of sophisticated analytical tools, particularly, quantitative optical imaging techniques including FCS and related fluctuation methods.
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Affiliation(s)
- Li Shang
- Institute
of Applied Physics, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
- Center
for Nano Energy Materials, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, China
| | - G. Ulrich Nienhaus
- Institute
of Applied Physics, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
- Institute
of Nanotechnology, Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen, Germany
- Institute
of Toxicology and Genetics, Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen, Germany
- Department
of Physics, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
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16
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Nienhaus K, Nienhaus GU. Chromophore photophysics and dynamics in fluorescent proteins of the GFP family. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:443001. [PMID: 27604321 DOI: 10.1088/0953-8984/28/44/443001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Proteins of the green fluorescent protein (GFP) family are indispensable for fluorescence imaging experiments in the life sciences, particularly of living specimens. Their essential role as genetically encoded fluorescence markers has motivated many researchers over the last 20 years to further advance and optimize these proteins by using protein engineering. Amino acids can be exchanged by site-specific mutagenesis, starting with naturally occurring proteins as templates. Optical properties of the fluorescent chromophore are strongly tuned by the surrounding protein environment, and a targeted modification of chromophore-protein interactions requires a profound knowledge of the underlying photophysics and photochemistry, which has by now been well established from a large number of structural and spectroscopic experiments and molecular-mechanical and quantum-mechanical computations on many variants of fluorescent proteins. Nevertheless, such rational engineering often does not meet with success and thus is complemented by random mutagenesis and selection based on the optical properties. In this topical review, we present an overview of the key structural and spectroscopic properties of fluorescent proteins. We address protein-chromophore interactions that govern ground state optical properties as well as processes occurring in the electronically excited state. Special emphasis is placed on photoactivation of fluorescent proteins. These light-induced reactions result in large structural changes that drastically alter the fluorescence properties of the protein, which enables some of the most exciting applications, including single particle tracking, pulse chase imaging and super-resolution imaging. We also present a few examples of fluorescent protein application in live-cell imaging experiments.
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Affiliation(s)
- Karin Nienhaus
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Wolfgang Gaede-Straße 1, 76131 Karlsruhe, Germany
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17
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Wang H, Shang L, Maffre P, Hohmann S, Kirschhöfer F, Brenner-Weiß G, Nienhaus GU. The Nature of a Hard Protein Corona Forming on Quantum Dots Exposed to Human Blood Serum. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2016; 12:5836-5844. [PMID: 27606563 DOI: 10.1002/smll.201602283] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 08/02/2016] [Indexed: 06/06/2023]
Abstract
Biological responses of cells and organisms to nanoparticle exposure crucially depend on the properties of the protein adsorption layer ("protein corona") forming on nanoparticle surfaces and their characterization is a crucial step toward a deep, mechanistic understanding of their build-up. Previously, adsorption of one type of model protein on nanoparticles was systematically studied in situ by using fluorescence correlation spectroscopy. Here, the first such study of interactions is presented between water-solubilized CdSe/ZnS quantum dots (QDs) and a complex biofluid, human blood serum. Despite the large number of proteins in serum, a protein layer of well-defined (average) thickness forming on QD surfaces is observed. Both the thickness and the apparent binding affinity depend on the type of QD surface ligand. Kinetic experiments reveal that the protein corona formed from serum is irreversibly bound, whereas the one formed from human serum albumin was earlier observed to be reversible. By using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and mass spectrometry, the most abundant serum proteins contributing to the formation of a hard corona on the QDs are identified.
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Affiliation(s)
- Haixia Wang
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Strasse 1, 76131, Karlsruhe, Germany
| | - Li Shang
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Strasse 1, 76131, Karlsruhe, Germany
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), 76344, Eggenstein-Leopoldshafen, Germany
- Center for Nano Energy Materials, School of Materials Science and Engineering, Northwestern Polytechnical University, Youyi West Road 127, Xi'an, 710072, China
| | - Pauline Maffre
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Strasse 1, 76131, Karlsruhe, Germany
| | - Siegfried Hohmann
- Institute of Functional Interfaces, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Frank Kirschhöfer
- Institute of Functional Interfaces, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Gerald Brenner-Weiß
- Institute of Functional Interfaces, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Gerd Ulrich Nienhaus
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Strasse 1, 76131, Karlsruhe, Germany
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), 76344, Eggenstein-Leopoldshafen, Germany
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
- Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, IL, 61801, USA
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18
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Ye P, Yu H, Houshmandi M. Three/four-dimensional (3D/4D) microscopic imaging and processing in clinical dental research. BMC Oral Health 2016; 16:84. [PMID: 27586147 PMCID: PMC5009657 DOI: 10.1186/s12903-016-0282-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 08/20/2016] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND Confocal laser scanning microscope (CLSM) has been widely employed in our laboratory for structural and functional analysis of clinical dental specimens and live cell imaging of cultured oral epithelial cells. METHODS In this vitro study, a Fluoview 1000 (Olympus) confocal system was utilised to study thick sections of carious lesions (40-100 μm) and periodontal disease tissue samples (20-40 μm) by 2D Z stacking imaging and 3-dimentional (3D) reconstruction. Four-dimensional (4D) imaging when including time or position points was used for live cells to assess penetration/localisation/co-localization of oral pathogen proteins and therapeutic drugs. RESULTS Three-dimensional (3D) reconstruction revealed latent features of carious hard tissues (strongly expressed amelogenin proteins in dentin tubules), and soft tissues (increased glial markers GFAP and S100B in pulp components). We also found the oral microbial specific pathogens, Porphyromonas gingivalis to be widely localised inside the periodontal pocket epithelial tissues as detected by 3D reconstruction from a series of 2D sections from periodontal disease tissue samples. 4D live cell imaging showed the diffusion patterns of fluorescent molecules in response to a bacterial virulence factor, the pathogen (gingipain haemagglutinin) domain that attacked epithelial integrity. This technology also showed uptake of a novel porphyrin-linked metronidazole antibiotic into epithelial cells to kill intracellular oral pathogen, P. gingivalis. CONCLUSIONS Three/four-dimensional (3D/4D) imaging and processing in confocal microscopy is of great interest and benefit to clinical dental researchers.
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Affiliation(s)
- Ping Ye
- Institute of Dental Research, Oral Health, Westmead Hospital, Westmead, Australia. .,Affiliation of Faculty of Dentistry, the University of Sydney, Sydney, Australia.
| | - Hong Yu
- Microscopy Laboratory, Westmead Institute for Medical Research, Westmead, Australia
| | - Mojgan Houshmandi
- Institute of Dental Research, Oral Health, Westmead Hospital, Westmead, Australia
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19
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Young SM, Bologa C, Prossnitz ER, Oprea TI, Sklar LA, Edwards BS. High-Throughput Screening with HyperCyt® Flow Cytometry to Detect Small Molecule Formylpeptide Receptor Ligands. ACTA ACUST UNITED AC 2016; 10:374-82. [PMID: 15964939 DOI: 10.1177/1087057105274532] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
High-throughput flow cytometry (HTFC), enabled by faster automated sample processing, represents a promising high- content approach for compound library screening. HyperCyt® is a recently developed automated HTFC analysis system by which cell samples are rapidly aspirated from microplate wells and delivered to the flow cytometer. The formylpeptide receptor (FPR) family of G protein–coupled receptors contributes to the localization and activation of tissue-damaging leukocytes at sites of chronic inflammation. Here, the authors describe development and application of an HTFC screening approach to detect potential anti-inflammatory compounds that block ligand binding to FPR. Using a homogeneous no-wash assay, samples were routinely processed at 1.5 s/well (~2500 cells analyzed/sample), allowing a 96-well plate to be processed in less than 2.5 min. Assay sensitivity and accuracy were validated by detection of a previously documented active compound with relatively low FPR affinity (sulfinpyrazone, inhibition constant [Ki]=14 μM) from among a collection of 880 compounds in the Prestwick Chemical Library. The HyperCyt® system was therefore demonstrated to be a robust, sensitive, and highly quantitative method with which to screen lead compound libraries in a 96-well format.
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Affiliation(s)
- Susan M Young
- Cytometry and Department of Pathology, Cancer Research and Treatment Center, University of New Mexico, Health Sciences Center, Albuquerque, NM 87131, USA
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20
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Gao P, Nienhaus GU. Confocal laser scanning microscopy with spatiotemporal structured illumination. OPTICS LETTERS 2016; 41:1193-1196. [PMID: 26977667 DOI: 10.1364/ol.41.001193] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 01/29/2016] [Indexed: 06/05/2023]
Abstract
Confocal laser scanning microscopy (CLSM), which is widely utilized in the biological and biomedical sciences, is limited in spatial resolution due to diffraction to about half the light wavelength. Here we have combined structured illumination with CLSM to enhance its spatial resolution. To this end, we have used a spatial light modulator (SLM) to generate fringe patterns of different orientations and phase shifts in the excitation spot without any mechanical movement. We have achieved 1.8 and 1.7 times enhanced lateral and axial resolutions, respectively, by synthesizing the object spectrum along different illumination directions. This technique is thus a promising tool for high-resolution morphological or fluorescence imaging, especially in deep tissue.
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21
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Nienhaus K, Nienhaus GU. Where Do We Stand with Super-Resolution Optical Microscopy? J Mol Biol 2016; 428:308-322. [DOI: 10.1016/j.jmb.2015.12.020] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 12/23/2015] [Accepted: 12/23/2015] [Indexed: 10/22/2022]
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22
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Maffre P, Brandholt S, Nienhaus K, Shang L, Parak WJ, Nienhaus GU. Effects of surface functionalization on the adsorption of human serum albumin onto nanoparticles - a fluorescence correlation spectroscopy study. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2014; 5:2036-47. [PMID: 25551031 PMCID: PMC4273259 DOI: 10.3762/bjnano.5.212] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 10/15/2014] [Indexed: 05/18/2023]
Abstract
By using fluorescence correlation spectroscopy (FCS), we have studied the adsorption of human serum albumin (HSA) onto Fe-Pt nanoparticles (NPs, 6 nm radius), CdSe/ZnS quantum dots (QDs, 5 nm radius) and Au and Ag nanoclusters (1-4 nm radius), which are enshrouded by various water-solubilizing surface layers exposing different chemical functional groups (carboxyl, amino and both), thereby endowing the NPs with different surface charges. We have also measured the effects of modified surface functionalizations on the protein via succinylation and amination. A step-wise increase in hydrodynamic radius with protein concentration was always observed, revealing formation of protein monolayers coating the NPs, independent of their surface charge. The differences in the thickness of the protein corona were rationalized in terms of the different orientations in which HSA adsorbs onto the NPs. The midpoints of the binding transition, which quantifies the affinity of HSA toward the NP, were observed to differ by almost four orders of magnitude. These variations can be understood in terms of specific Coulombic interactions between the proteins and the NP surfaces.
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Affiliation(s)
- Pauline Maffre
- Institute of Applied Physics and Center for Functional Nanostructures, Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Strasse 1, 76131 Karlsruhe, Germany
| | - Stefan Brandholt
- Institute of Applied Physics and Center for Functional Nanostructures, Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Strasse 1, 76131 Karlsruhe, Germany
| | - Karin Nienhaus
- Institute of Applied Physics and Center for Functional Nanostructures, Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Strasse 1, 76131 Karlsruhe, Germany
| | - Li Shang
- Institute of Applied Physics and Center for Functional Nanostructures, Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Strasse 1, 76131 Karlsruhe, Germany
| | - Wolfgang J Parak
- Department of Physics, Philipps University Marburg, Renthof 7, 35037 Marburg, Germany
| | - G Ulrich Nienhaus
- Institute of Applied Physics and Center for Functional Nanostructures, Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Strasse 1, 76131 Karlsruhe, Germany
- Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, IL 61801, USA
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23
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Shang L, Nienhaus K, Nienhaus GU. Engineered nanoparticles interacting with cells: size matters. J Nanobiotechnology 2014; 12:5. [PMID: 24491160 PMCID: PMC3922601 DOI: 10.1186/1477-3155-12-5] [Citation(s) in RCA: 787] [Impact Index Per Article: 78.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Accepted: 01/31/2014] [Indexed: 11/10/2022] Open
Abstract
With the rapid advancement of nanoscience and nanotechnology, detailed knowledge of interactions between engineered nanomaterials and cells, tissues and organisms has become increasingly important, especially in regard to possible hazards to human health. This review intends to give an overview of current research on nano-bio interactions, with a focus on the effects of NP size on their interactions with live cells. We summarize common techniques to characterize NP size, highlight recent work on the impact of NP size on active and passive cellular internalization and intracellular localization. Cytotoxic effects are also discussed.
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Affiliation(s)
| | | | - Gerd Ulrich Nienhaus
- Institute of Applied Physics and Center for Functional Nanostructures (CFN), Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Strasse 1, 76131 Karlsruhe, Germany.
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Treuel L, Brandholt S, Maffre P, Wiegele S, Shang L, Nienhaus GU. Impact of protein modification on the protein corona on nanoparticles and nanoparticle-cell interactions. ACS NANO 2014; 8:503-13. [PMID: 24377255 DOI: 10.1021/nn405019v] [Citation(s) in RCA: 287] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Recent studies have firmly established that cellular uptake of nanoparticles is strongly affected by the presence and the physicochemical properties of a protein adsorption layer around these nanoparticles. Here, we have modified human serum albumin (HSA), a serum protein often used in model studies of protein adsorption onto nanoparticles, to alter its surface charge distribution and investigated the consequences for protein corona formation around small (radius ∼5 nm), dihydrolipoic acid-coated quantum dots (DHLA-QDs) by using fluorescence correlation spectroscopy. HSA modified by succinic anhydride (HSAsuc) to generate additional carboxyl groups on the protein surface showed a 3-fold decreased binding affinity toward the nanoparticles. A 1000-fold enhanced affinity was observed for HSA modified by ethylenediamine (HSAam) to increase the number of amino functions on the protein surface. Remarkably, HSAsuc formed a much thicker protein adsorption layer (8.1 nm) than native HSA (3.3 nm), indicating that it binds in a distinctly different orientation on the nanoparticle, whereas the HSAam corona (4.6 nm) is only slightly thicker. Notably, protein binding to DHLA-QDs was found to be entirely reversible, independent of the modification. We have also measured the extent and kinetics of internalization of these nanoparticles without and with adsorbed native and modified HSA by HeLa cells. Pronounced variations were observed, indicating that even small physicochemical changes of the protein corona may affect biological responses.
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Affiliation(s)
- Lennart Treuel
- Institute of Applied Physics and Center for Functional Nanostructures (CFN), Karlsruhe Institute of Technology (KIT) , 76128 Karlsruhe, Germany
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25
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Treuel L, Eslahian KA, Docter D, Lang T, Zellner R, Nienhaus K, Nienhaus GU, Stauber RH, Maskos M. Physicochemical characterization of nanoparticles and their behavior in the biological environment. Phys Chem Chem Phys 2014; 16:15053-67. [DOI: 10.1039/c4cp00058g] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Whilst the physical and chemical properties of nanoparticles in the gas or idealized solvent phase can nowadays be characterized with sufficient accuracy, this is no longer the case for particles in the presence of a complex biological environment.
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Affiliation(s)
- L. Treuel
- Fraunhofer ICT-IMM
- 55129 Mainz, Germany
- Institute of Physical Chemistry
- University of Duisburg-Essen
- 45141 Essen, Germany
| | | | - D. Docter
- Molecular and Cellular Oncology/Mainz Screening Center (MSC)
- University Hospital of Mainz
- 55101 Mainz, Germany
| | - T. Lang
- Fraunhofer ICT-IMM
- 55129 Mainz, Germany
| | - R. Zellner
- Institute of Physical Chemistry
- University of Duisburg-Essen
- 45141 Essen, Germany
| | - K. Nienhaus
- Institute of Applied Physics
- Karlsruhe Institute of Technology (KIT)
- 76128 Karlsruhe, Germany
| | - G. U. Nienhaus
- Institute of Applied Physics
- Karlsruhe Institute of Technology (KIT)
- 76128 Karlsruhe, Germany
- Department of Physics
- University of Illinois at Urbana-Champaign
| | - R. H. Stauber
- Molecular and Cellular Oncology/Mainz Screening Center (MSC)
- University Hospital of Mainz
- 55101 Mainz, Germany
| | - M. Maskos
- Fraunhofer ICT-IMM
- 55129 Mainz, Germany
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26
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Edwards BS, Young SM, Saunders MJ, Bologa C, Oprea TI, Ye RD, Prossnitz ER, Graves SW, Sklar LA. High-throughput flow cytometry for drug discovery. Expert Opin Drug Discov 2013; 2:685-96. [PMID: 23488958 DOI: 10.1517/17460441.2.5.685] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
High-throughput flow cytometry exploits a novel many-samples/one-file approach to dramatically speed data acquisition, limit aspirated sample volume to as little as 2 μl/well and produce multisample data sets that facilitate automated analysis of samples in groups as well as individually. It has been successfully applied to both cell- and microsphere-based bioassays in 96- and 384-well formats, to screen tens-of-thousands of compounds and identify novel bioactive structures. High-content multiparametric analysis capabilities have been exploited for assay multiplexing, allowing the assessment of biologic selectivity and specificity to be an integral component of primary screens. These and other advances in the last decade have contributed to the application of flow cytometry as a uniquely powerful tool for probing biologic and chemical diversity and complex systems biology.
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Affiliation(s)
- Bruce S Edwards
- Cytometry and Department of Pathology, CRTC, UNM HSC, MS08-4630, Albuquerque, NM 87131, USA +1 505 272 6206 ; +1 505 272 6695 ;
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27
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Krausz E, de Hoogt R, Gustin E, Cornelissen F, Grand-Perret T, Janssen L, Vloemans N, Wuyts D, Frans S, Axel A, Peeters PJ, Hall B, Cik M. Translation of a tumor microenvironment mimicking 3D tumor growth co-culture assay platform to high-content screening. ACTA ACUST UNITED AC 2012; 18:54-66. [PMID: 22923784 DOI: 10.1177/1087057112456874] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
For drug discovery, cell-based assays are becoming increasingly complex to mimic more realistically the nature of biological processes and their diversifications in diseases. Multicellular co-cultures embedded in a three-dimensional (3D) matrix have been explored in oncology to more closely approximate the physiology of the human tumor microenvironment. High-content analysis is the ideal technology to characterize these complex biological systems, although running such complex assays at higher throughput is a major endeavor. Here, we report on adapting a 3D tumor co-culture growth assay to automated microscopy, and we compare various imaging platforms (confocal vs. nonconfocal) with correlating automated image analysis solutions to identify optimal conditions and settings for future larger scaled screening campaigns. The optimized protocol has been validated in repeated runs where established anticancer drugs have been evaluated for performance in this innovative assay.
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Affiliation(s)
- Eberhard Krausz
- Janssen R&D, a Division of Janssen Pharmaceutica NV, Beerse, Belgium.
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28
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Lawlor C, O’Sullivan MP, Sivadas N, O’Leary S, Gallagher PJ, Keane J, Cryan SA. The Application of High-Content Analysis in the Study of Targeted Particulate Delivery Systems for Intracellular Drug Delivery to Alveolar Macrophages. Mol Pharm 2011; 8:1100-12. [DOI: 10.1021/mp1004178] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Ciaran Lawlor
- School of Pharmacy, Royal College of Surgeons in Ireland, Dublin 2, Ireland
- Institute of Molecular Medicine, Trinity College Health Science Building, St. James’ Hospital, Dublin 8, Ireland
| | - Mary P. O’Sullivan
- Institute of Molecular Medicine, Trinity College Health Science Building, St. James’ Hospital, Dublin 8, Ireland
| | - Neera Sivadas
- School of Pharmacy, Royal College of Surgeons in Ireland, Dublin 2, Ireland
| | - Seonadh O’Leary
- Institute of Molecular Medicine, Trinity College Health Science Building, St. James’ Hospital, Dublin 8, Ireland
| | - Paul J. Gallagher
- School of Pharmacy, Royal College of Surgeons in Ireland, Dublin 2, Ireland
| | - Joseph Keane
- Institute of Molecular Medicine, Trinity College Health Science Building, St. James’ Hospital, Dublin 8, Ireland
| | - Sally-Ann Cryan
- School of Pharmacy, Royal College of Surgeons in Ireland, Dublin 2, Ireland
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29
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Maffre P, Nienhaus K, Amin F, Parak WJ, Nienhaus GU. Characterization of protein adsorption onto FePt nanoparticles using dual-focus fluorescence correlation spectroscopy. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2011; 2:374-83. [PMID: 22003445 PMCID: PMC3190609 DOI: 10.3762/bjnano.2.43] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Accepted: 06/06/2011] [Indexed: 05/18/2023]
Abstract
Using dual-focus fluorescence correlation spectroscopy, we have analyzed the adsorption of three human blood serum proteins, namely serum albumin, apolipoprotein A-I and apolipoprotein E4, onto polymer-coated, fluorescently labeled FePt nanoparticles (~12 nm diameter) carrying negatively charged carboxyl groups on their surface. For all three proteins, a step-wise increase in hydrodynamic radius with protein concentration was observed, strongly suggesting the formation of protein monolayers that enclose the nanoparticles. Consistent with this interpretation, the absolute increase in hydrodynamic radius can be correlated with the molecular shapes of the proteins known from X-ray crystallography and solution experiments, indicating that the proteins bind on the nanoparticles in specific orientations. The equilibrium dissociation coefficients, measuring the affinity of the proteins to the nanoparticles, were observed to differ by almost four orders of magnitude. These variations can be understood in terms of the electrostatic properties of the proteins. From structure-based calculations of the surface potentials, positively charged patches of different extents can be revealed, through which the proteins interact electrostatically with the negatively charged nanoparticle surfaces.
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Affiliation(s)
- Pauline Maffre
- Institute of Applied Physics and Center for Functional Nanostructures, Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Straße 1, 76131 Karlsruhe, Germany
| | - Karin Nienhaus
- Institute of Applied Physics and Center for Functional Nanostructures, Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Straße 1, 76131 Karlsruhe, Germany
| | - Faheem Amin
- Department of Physics, Philipps University Marburg, Renthof 7, 35037 Marburg, Germany
| | - Wolfgang J Parak
- Department of Physics, Philipps University Marburg, Renthof 7, 35037 Marburg, Germany
| | - G Ulrich Nienhaus
- Institute of Applied Physics and Center for Functional Nanostructures, Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Straße 1, 76131 Karlsruhe, Germany
- Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, IL 61801, USA
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30
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Lehmann AD, Parak WJ, Zhang F, Ali Z, Röcker C, Nienhaus GU, Gehr P, Rothen-Rutishauser B. Fluorescent-magnetic hybrid nanoparticles induce a dose-dependent increase in proinflammatory response in lung cells in vitro correlated with intracellular localization. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2010; 6:753-62. [PMID: 20205203 DOI: 10.1002/smll.200901770] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Abstract
Iron-platinum nanoparticles embedded in a poly(methacrylic acid) (PMA) polymer shell and fluorescently labeled with the dye ATTO 590 (FePt-PMA-ATTO-2%) are investigated in terms of their intracellular localization in lung cells and potential to induce a proinflammatory response dependent on concentration and incubation time. A gold core coated with the same polymer shell (Au-PMA-ATTO-2%) is also included. Using laser scanning and electron microscopy techniques, it is shown that the FePt-PMA-ATTO-2% particles penetrate all three types of cell investigated but to a higher extent in macrophages and dendritic cells than epithelial cells. In both cell types of the defense system but not in epithelial cells, a particle-dose-dependent increase of the cytokine tumor necrosis factor alpha (TNFalpha) is found. By comparing the different nanoparticles and the mere polymer shell, it is shown that the cores combined with the shells are responsible for the induction of proinflammatory effects and not the shells alone. It is concluded that the uptake behavior and the proinflammatory response upon particle exposure are dependent on the time, cell type, and cell culture.
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Affiliation(s)
- Andrea D Lehmann
- Institute of Anatomy, University of Bern, Bern 3012, Switzerland
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31
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Nierth A, Kobitski AY, Nienhaus GU, Jäschke A. Anthracene−BODIPY Dyads as Fluorescent Sensors for Biocatalytic Diels−Alder Reactions. J Am Chem Soc 2010; 132:2646-54. [DOI: 10.1021/ja9084397] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alexander Nierth
- Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Im Neuenheimer Feld 364, Heidelberg 69120, Germany, Institute of Applied Physics and Center for Functional Nanostructures, Karlsruhe Institute of Technology, Wolfgang-Gaede-Strasse 1, 76131 Karlsruhe, Germany, and Department of Physics, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801
| | - Andrei Yu. Kobitski
- Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Im Neuenheimer Feld 364, Heidelberg 69120, Germany, Institute of Applied Physics and Center for Functional Nanostructures, Karlsruhe Institute of Technology, Wolfgang-Gaede-Strasse 1, 76131 Karlsruhe, Germany, and Department of Physics, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801
| | - G. Ulrich Nienhaus
- Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Im Neuenheimer Feld 364, Heidelberg 69120, Germany, Institute of Applied Physics and Center for Functional Nanostructures, Karlsruhe Institute of Technology, Wolfgang-Gaede-Strasse 1, 76131 Karlsruhe, Germany, and Department of Physics, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801
| | - Andres Jäschke
- Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Im Neuenheimer Feld 364, Heidelberg 69120, Germany, Institute of Applied Physics and Center for Functional Nanostructures, Karlsruhe Institute of Technology, Wolfgang-Gaede-Strasse 1, 76131 Karlsruhe, Germany, and Department of Physics, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801
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Abstract
In the past decade, high-content screening has become a highly developed approach to obtaining richly descriptive quantitative phenotypic data using automated microscopy. From early use in drug screening, the technique has evolved to embrace a diverse range of applications in both academic and industrial sectors and is now widely recognized as providing an efficient and effective approach to large-scale programs investigating cell biology in situ and in context.
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Affiliation(s)
- Nick Thomas
- GE Healthcare, Whitchurch, Cardiff, United Kingdom,
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33
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Kredel S, Wolff M, Wiedenmann J, Moepps B, Nienhaus GU, Gierschik P, Kistler B, Heilker R. CXCR2 inverse agonism detected by arrestin redistribution. JOURNAL OF BIOMOLECULAR SCREENING 2009; 14:1076-91. [PMID: 19773589 DOI: 10.1177/1087057109344616] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
To study CXCR2 modulated arrestin redistribution, the authors employed arrestin as a fusion protein containing either the Aequorea victoria-derived enhanced green fluorescent protein (EGFP) or a recently developed mutant of eqFP611, a red fluorescent protein derived from Entacmaea quadricolor. This mutant, referred to as RFP611, had earlier been found to assume a dimeric quarternary structure. It was therefore employed in this work as a "tandem" (td) construct for pseudo-monomeric fusion protein labeling. Both arrestin fusion proteins, containing either td-RFP611 (Arr-td-RFP611) or enhanced green fluorescent protein (EGFP; Arr-EGFP), were found to colocalize with internalized fluorescently labeled Gro-alpha a few minutes after Gro-alpha addition. Intriguingly, however, Arr-td-RFP611 and Arr-EGFP displayed distinct cellular distribution patterns in the absence of any CXCR2-activating ligand. Under these conditions, Arr-td-RFP611 showed a largely homogeneous cytosolic distribution, whereas Arr-EGFP segregated, to a large degree, into granular spots. These observations indicate a higher sensitivity of Arr EGFP to the constitutive activity of CXCR2 and, accordingly, an increased arrestin redistribution to coated pits and endocytic vesicles. In support of this interpretation, the authors found the known CXCR2 antagonist Sch527123 to act as an inverse agonist with respect to Arr-EGFP redistribution. The inverse agonistic properties of Sch527123 were confirmed in vitro in a guanine nucleotide binding assay, revealing an IC(50) value similar to that observed for Arr-EGFP redistribution. Thus, the redistribution assay, when based on Arr-EGFP, enables the profiling of antagonistic test compounds with respect to inverse agonism. When based on Arr-td-RFP611, the assay may be employed to study CXCR2 agonism or neutral antagonism.
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Affiliation(s)
- Simone Kredel
- Institute of Zoology and Endocrinology, Ulm University Medical Center, Ulm, Germany
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34
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Jiang X, Weise S, Hafner M, Röcker C, Zhang F, Parak WJ, Nienhaus GU. Quantitative analysis of the protein corona on FePt nanoparticles formed by transferrin binding. J R Soc Interface 2009; 7 Suppl 1:S5-S13. [PMID: 19776149 DOI: 10.1098/rsif.2009.0272.focus] [Citation(s) in RCA: 152] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Nanoparticles are finding a rapidly expanding range of applications in research and technology, finally entering our daily life in medical, cosmetic or food products. Their ability to invade all regions of an organism including cells and cellular organelles offers new strategies for medical diagnosis and therapy (nanomedicine), but their safe use requires a deep knowledge about their interactions with biological systems at the molecular level. Upon incorporation, nanoparticles are exposed to biological fluids from which they adsorb proteins and other biomolecules to form a 'protein corona'. These nanoparticle-protein interactions are still poorly understood and quantitative studies to characterize them remain scarce. Here we have quantitatively analysed the adsorption of human transferrin onto small (radius approx. 5 nm) polymer-coated FePt nanoparticles by using fluorescence correlation spectroscopy. Transferrin binds to the negatively charged nanoparticles with an affinity of approximately 26 microM in a cooperative fashion and forms a monolayer with a thickness of 7 nm. By using confocal fluorescence microscopy, we have observed that the uptake of FePt nanoparticles by HeLa cells is suppressed by the protein corona compared with the bare nanoparticles.
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Affiliation(s)
- Xiue Jiang
- Institute of Biophysics, University of Ulm, Albert Einstein-Allee 11, 89081 Ulm, Germany
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35
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Heilker R, Wolff M, Tautermann CS, Bieler M. G-protein-coupled receptor-focused drug discovery using a target class platform approach. Drug Discov Today 2009; 14:231-40. [PMID: 19121411 DOI: 10.1016/j.drudis.2008.11.011] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2008] [Revised: 11/05/2008] [Accepted: 11/26/2008] [Indexed: 11/27/2022]
Abstract
In recent years, several large pharmaceutical companies have taken a novel approach to drug discovery biology and chemistry in that they channel their efforts with respect to particular target classes, such as G-protein-coupled receptors (GPCRs), toward dedicated, specialized teams. Benefits of such an organizational structure are the prospects of establishing several target-family-specific experimental techniques and skill sets, thereby enabling a comprehensive functional profiling of drug candidates in different pharmacological respects. In this context, the recently increased number of reports on GPCR ligand-biased signaling has further spurred the efforts in the pharmaceutical industry toward broader biological characterization of the test compounds, for example employing high-content screening to analyze different GPCR ligand-induced signaling pathways. The knowledge of the disease-relevant functional properties of the small molecule GPCR ligands enables target-specific chemical optimization and GPCR-subclass-directed library design. In the case of GPCRs, where little--although at present slowly expanding--structural information on the targets is available, the modeling of GPCR structures crucially depends on biological validation (typically supported by site-directed mutagenesis of the GPCR ligand binding site). In this review, we aim to recapitulate efforts in the pharmaceutical industry to address GPCR-directed drug discovery in a target-class-directed platform approach: establishing GPCR-specific biological assay panels and creating computational chemistry methods for finding and optimizing small molecules modulating the activity of GPCRs.
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Affiliation(s)
- Ralf Heilker
- Department of Lead Discovery, Boehringer Ingelheim Pharma GmbH & Co KG, Biberach, Germany.
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36
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Wolff M, Kauschke SG, Schmidt S, Heilker R. Activation and Translocation of Glucokinase in Rat Primary Hepatocytes Monitored by High Content Image Analysis. ACTA ACUST UNITED AC 2008; 13:837-46. [DOI: 10.1177/1087057108323910] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In the liver, glucokinase (GK) regulatory protein (GKRP) negatively modulates the metabolic enzyme GK by locking it in an inactive state in the nucleus. Here, the authors established a high content screening assay in the 384-well microplate format to measure the nucleus-to-cytoplasm translocation of GK by reagents that destabilize the interaction between GK and GKRP. As a cellular model system, primary rat hepatocytes endogenously expressing both GK and GKRP at physiological levels were used. The GK translocation assay was robust, displayed limited day-to-day variability, and delivered good Z′ statistics. The increase of the glucose concentration in the extracellular medium from a low glucose situation (2.8 mM) to beyond its physiological set point value of 5 mM was found to drive GK from the nucleus into the cytoplasm. Likewise, both fructose (converted intracellularly into fructose-1-phosphate) and a known allosteric GK activator were found to induce the export of GK from the nucleus and to synergistically enhance the effects of medium or high glucose concentrations with respect to GK translocation. Transfer of the high content screening format to a semiautomated medium throughput screening platform enabled the profiling of large compound numbers with respect to allosteric activation of GK. ( Journal of Biomolecular Screening 2008:837-846)
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Affiliation(s)
- Michael Wolff
- Department of Lead Discovery, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany
| | - Stefan G. Kauschke
- Department of Metabolic Diseases Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany
| | - Susanne Schmidt
- Department of Lead Discovery, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany
| | - Ralf Heilker
- Department of Lead Discovery, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany, -ingelheim.com
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37
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Tron K, Manolov DE, Röcker C, Kächele M, Torzewski J, Nienhaus GU. C-reactive protein specifically binds to Fcgamma receptor type I on a macrophage-like cell line. Eur J Immunol 2008; 38:1414-22. [PMID: 18412163 DOI: 10.1002/eji.200738002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
C-reactive protein (CRP) is a prototype acute-phase protein that may be intimately involved in human disease. Its cellular receptors are still under debate; the main candidates are FcR for immunoglobulin G, as CRP was shown to bind specifically to FcgammaRI and FcgammaRIIa. Using ultrasensitive confocal live-cell imaging, we have studied CRP binding to FcgammaR naturally expressed in the plasma membranes of cells from a human leukemia cell line (Mono Mac 6). These macrophage-like cells express high levels of FcgammaRI and FcgammaRII. They were shown to bind fluorescently labeled CRP with micromolar affinity, KD = (6.6 +/- 1.5) microM. CRP binding could be inhibited by pre-incubation with human but not mouse IgG and was thus FcgammaR-specific. Blocking of FcgammaRI by an FcgammaRI-specific antibody abolished CRP binding essentially completely, whereas application of antibodies against FcgammaRII did not have a noticeable effect. In fluorescence images of Mono Mac 6 cells, the intensity patterns of bound CRP were correlated with those of FcgammaRI, but not FcgammaRII. These results provide clear evidence of specific interactions between CRP and FcgammaR (predominantly FcgammaRI) naturally expressed on macrophage-like cells.
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Affiliation(s)
- Kyrylo Tron
- Institute of Biophysics, University of Ulm, Ulm, Germany
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38
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Haasen D, Merk S, Seither P, Martyres D, Hobbie S, Heilker R. Pharmacological Profiling of Chemokine Receptor–Directed Compounds Using High-Content Screening. ACTA ACUST UNITED AC 2007; 13:40-53. [DOI: 10.1177/1087057107312128] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
High-content screening, typically defined as automated fluorescence microscopy combined with image analysis, is now well established as a means to study test compound effects in cellular disease-modeling systems. In this work, the authors establish several high-content screening assays in the 384-well format to measure the activation of the CC-type chemokine receptors 2B and 3 (CCR2B, CCR3). As a cellular model system, the authors use Chinese hamster ovary cells, stably transfected with 1 of the respective receptors. They characterize receptor stimulation by human monocyte chemoattractant protein-1 for CCR2B and by human eotaxin-1 for CCR3: Receptor internalization and receptor-induced phosphorylation of ERK1/2 (pERK) were quantified using fluorescence imaging and image analysis. The 4 assay formats were robust, displayed little day-to-day variability, and delivered good Z′ statistics for both CCRs. For each of the 2 receptors, the authors evaluated the potency of inhibitory compounds in the internalization format and the pERK assay and compared the results with those from other assays (ligand displacement binding, Ca2+ mobilization, guanosine triphosphate exchange, chemotaxis). Both physiological agonists and test compounds differed significantly with respect to potencies and efficacies in the various profiling assays. The diverse assay formats delivered partially overlapping and partially complementary information, enabling the authors to reduce the probability of test compound—related technology artifacts and to specify the mode of action for individual test compounds. Transfer of the high-content screening format to a fully automated medium-throughput screening platform for CCR3 enabled the profiling of large compound numbers with respect to G protein signaling and possible tolerance-inducing liabilities. ( Journal of Biomolecular Screening 2008:40-53)
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Affiliation(s)
- Dorothea Haasen
- Department of Integrated Lead Discovery, Boehringer Ingelheim Pharma GmbH & Co KG, Biberach, Germany
| | - Susanne Merk
- Department of Integrated Lead Discovery, Boehringer Ingelheim Pharma GmbH & Co KG, Biberach, Germany
| | - Peter Seither
- Department of Respiratory Research, Boehringer Ingelheim Pharma GmbH & Co KG, Biberach, Germany
| | - Domnic Martyres
- Department of Chemical Research, Boehringer Ingelheim Pharma GmbH & Co KG, Biberach, Germany
| | - Silke Hobbie
- Department of Respiratory Research, Boehringer Ingelheim Pharma GmbH & Co KG, Biberach, Germany
| | - Ralf Heilker
- Department of Integrated Lead Discovery, Boehringer Ingelheim Pharma GmbH & Co KG, Biberach, Germany, -ingelheim.com
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39
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Rajwa B. Image cytometry goes multiphoton. Cytometry A 2007; 71:973-5. [PMID: 18023066 DOI: 10.1002/cyto.a.20479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Bartek Rajwa
- Purdue University Cytometry Laboratories, Bindley Bioscience Center, West Lafayette, Indiana 47907, USA.
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40
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Heilker R. High Content Screening to Monitor G Protein-Coupled Receptor Internalisation. ACTA ACUST UNITED AC 2007:229-47. [PMID: 17703585 DOI: 10.1007/2789_2006_011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
G protein-coupled receptors (GPCRs) fulfil a broad diversity of physiological functions in areas such as neurotransmission, respiration, cardiovascular action, pain and more. Consequently, they are considered as the most successful group of therapeutic targets on the pharmaceutical market, and the search for compounds that interfere with GPCR function in a specific and selective way is a major focus of the pharmaceutical industry. High Content Screening (HCS), a combination of fluorescence microscopic imaging and automated image analysis, has become a frequently employed tool to study test compound effects in cellular disease modelling systems. One way to functionally analyse the effect of test compounds on GPCRs by HCS relies on the broadly observed phenomenon of desensitisation. Agonist stimulation of most GPCRs leads to their intracellular phosphorylation and subsequent internalisation, resulting in the termination of receptor signalling and the seclusion of the GPCR from further extracellular stimulation. Complementary to other functional GPCR drug discovery assays, GPCR internalisation assays enable a desensitisation-focussed pharmacological analysis of test compounds.
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Affiliation(s)
- R Heilker
- Boehringer Ingelheim Pharma GmbH Co. KG, Department of Lead Discovery, Birkendorfer Strasse 65, 88397 Biberach an der Riss, Germany.
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41
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Kobitski AY, Nierth A, Helm M, Jäschke A, Nienhaus GU. Mg2+-dependent folding of a Diels-Alderase ribozyme probed by single-molecule FRET analysis. Nucleic Acids Res 2007; 35:2047-59. [PMID: 17344321 PMCID: PMC1874616 DOI: 10.1093/nar/gkm072] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Here, we report a single-molecule fluorescence resonance energy transfer (FRET) study of a Diels-Alderase (DAse) ribozyme, a 49-mer RNA with true catalytic properties. The DAse ribozyme was labeled with Cy3 and Cy5 as a FRET pair of dyes to observe intramolecular folding, which is a prerequisite for its recognition and turnover of two organic substrate molecules. FRET efficiency histograms and kinetic data were taken on a large number of surface-immobilized ribozyme molecules as a function of the Mg(2+) concentration in the buffer solution. From these data, three separate states of the DAse ribozyme can be distinguished, the unfolded (U), intermediate (I) and folded (F) states. A thermodynamic model was developed to quantitatively analyze the dependence of these states on the Mg(2+) concentration. The FRET data also provide information on structural properties. The I state shows a strongly cooperative compaction with increasing Mg(2+) concentration that arises from association with several Mg(2+) ions. This transition is followed by a second Mg(2+)-dependent cooperative transition to the F state. The observation of conformational heterogeneity and continuous fluctuations between the I and F states on the approximately 100 ms timescale offers insight into the folding dynamics of this ribozyme.
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Affiliation(s)
- Andrei Yu. Kobitski
- Institute of Biophysics, University of Ulm, 89069 Ulm, Germany, Institute of Pharmacy and Molecular Biotechnology, University of Heidelberg, 69120 Heidelberg, Germany and Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Alexander Nierth
- Institute of Biophysics, University of Ulm, 89069 Ulm, Germany, Institute of Pharmacy and Molecular Biotechnology, University of Heidelberg, 69120 Heidelberg, Germany and Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Mark Helm
- Institute of Biophysics, University of Ulm, 89069 Ulm, Germany, Institute of Pharmacy and Molecular Biotechnology, University of Heidelberg, 69120 Heidelberg, Germany and Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Andres Jäschke
- Institute of Biophysics, University of Ulm, 89069 Ulm, Germany, Institute of Pharmacy and Molecular Biotechnology, University of Heidelberg, 69120 Heidelberg, Germany and Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - G. Ulrich Nienhaus
- Institute of Biophysics, University of Ulm, 89069 Ulm, Germany, Institute of Pharmacy and Molecular Biotechnology, University of Heidelberg, 69120 Heidelberg, Germany and Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- *To whom correspondence should be addressed. +1-49-731-50-23050+1-49-731-50-23059
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43
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Abstract
Very recent developments in instrumentation and image analysis have made microscopy applicable to high-throughput screening (HTS). For 'High-Content Screening' modern automated microscopy systems provide a throughput of up to 100,000 (confocal) images, with amazingly high resolution, of cells fluorescently stained using multiple colours that are imaged simultaneously during the screen. Image analysis tools provide multi-parametric pattern extraction and quantification on-the-fly. Big pharmaceutical companies have presented image-based screens of more than 100,000 compounds, while academia has published data on large RNA interference screens for functional genomics. Numerous whole-genome sequencing projects have been completed and published. Gene annotation is still in flux. Nevertheless, about 23,000 human genes have been reliably annotated. Additionally, gene expression array technologies and proteomics have added further data on molecules present in cells and tissues. The major challenge of the present and future is to unravel the detailed function of all these gene products and their interaction. One way to gain insight, is to design oligonucleotides that induce lack-of-function phenotypes by specifically inhibiting protein production.
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Affiliation(s)
- Eberhard Krausz
- HT-Technology Development Studio (TDS), Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG), Pfotenhauerstrasse 108, D-01307 Dresden, Germany.
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44
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Chan GKY, Richards GR, Peters M, Simpson PB. High content kinetic assays of neuronal signaling implemented on BD pathway HT. Assay Drug Dev Technol 2006; 3:623-36. [PMID: 16438658 DOI: 10.1089/adt.2005.3.623] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A great deal of information can be gained from kinetic fluorescence-based measurement of cellular responses; however, until recently the use of such approaches has been limited by the manual nature of the instrumentation available. Higher-throughput kinetic studies of signaling pathways are greatly facilitated by new confocal, liquid handling-enabled, high content screening (HCS) platforms. In the present work, we have implemented one such instrument, the BD(TM) Pathway HT bioimager (BD Biosciences, Rockville, MD), for studying regulation of neuronal signaling pathways. We have established a neuronal calcium oscillation model, whereby rate of oscillation, amplitude of oscillation, and level of synchronicity across the culture can be measured. We have implemented membrane potential measurement using fluorescence resonance energy transfer-based dyes, for single cell characterization on this platform, showing the benefits of a truly flexible excitation and recording system; this dye combination cannot be readily implemented on all HCS platforms because of constraints of excitation wavelengths. We have validated long-term intracellular calcium imaging experiments, using innovative dyes and BD Pathway HT's spinning disk-based confocal excitation. To maximize both throughput and reproducibility, walk-away automation integration of this bioimaging technology has been implemented, producing an affordable, compact platform for fully automated kinetic HCS.
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Affiliation(s)
- Grace K Y Chan
- Automated Imaging & Electrophysiology Group, The Neuroscience Research Centre, Merck Sharp & Dohme Research Laboratories, Harlow, Essex, UK
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Richards GR, Jack AD, Platts A, Simpson PB. Measurement and analysis of calcium signaling in heterogeneous cell cultures. Methods Enzymol 2006; 414:335-47. [PMID: 17110201 DOI: 10.1016/s0076-6879(06)14019-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
High-content imaging platforms capable of studying kinetic responses at a single-cell level have elevated kinetic recording techniques from labor-intensive low-throughput experiments to potential high-throughput screening assays. We have applied this technology to the investigation of heterogeneous cell cultures derived from primary neural tissue. The neuronal cultures mature into a coupled network and display spontaneous oscillations in intracellular calcium, which can be modified by the addition of pharmacological agents. We have developed algorithms to perform Fourier analysis and quantify both the degree of synchronization and the effects of modulators on the oscillations. Functional and phenotypic experiments can be combined using this approach. We have used post-hoc immunolabeling to identify subpopulations of cells in cocultures and to dissect the calcium responses of these cells from the population response. The combination of these techniques represents a powerful tool for drug discovery.
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Affiliation(s)
- Gillian R Richards
- The Neuroscience Research Centre, Merck Sharp and Dohme Research Laboratories, Essex, United Kingdom
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Wolff M, Wiedenmann J, Nienhaus GU, Valler M, Heilker R. Novel fluorescent proteins for high-content screening. Drug Discov Today 2006; 11:1054-60. [PMID: 17129823 DOI: 10.1016/j.drudis.2006.09.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2006] [Revised: 08/18/2006] [Accepted: 09/11/2006] [Indexed: 12/01/2022]
Abstract
The development of fast microscopic imaging devices has enabled the application of automated fluorescence microscopy to pharmaceutical high-throughput drug-discovery assays, referred to as high-content screening (HCS). Initially, green fluorescent protein and its derivatives from Aequorea Victoria, and later anthozoan fluorescent proteins (FPs) have become potent tools as live-cell markers in HCS assays. We illustrate the broad applicability of classic and novel FPs to drug-discovery assays, giving example applications of the use of FPs in multiplexed imaging as fluorescent timers, photosensitizers and pulse-chase labels, and for robotically integrated compound testing.
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Affiliation(s)
- Michael Wolff
- Department of Lead Discovery, Boehringer Ingelheim Pharma GmbH and Co. KG, Birkendorfer Str.65, D-88397 Biberach, Germany
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Schreiter C, Gjoni M, Hovius R, Martinez KL, Segura JM, Vogel H. Reversible sequential-binding probe receptor-ligand interactions in single cells. Chembiochem 2006; 6:2187-94. [PMID: 16270372 DOI: 10.1002/cbic.200500216] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
With the reversible sequential (ReSeq) binding assay,we present a novel approach for the ultrasensitive profiling of receptor function in single living cells. This assay is based on the repetitive application of fluorescent ligands that have fast association-dissociation kinetics. We chose the nicotinic-acetylcholine receptor (nAChR) as a prototypical example and performed ReSeq equilibrium, kinetic, and competition-binding assays using fluorescent derivatives of the antagonist alpha-conotoxin GI (alpha-CnTx). Thereby, we determined the binding constants of unlabeled alpha-CnTx and d-tubocurarine. The high selectivity of alpha-CnTx for muscle-type nAChR made it possible to observe specific binding even in the presence of other nAChR subtypes. Imaging of individual nAChRs and ligand-binding cycles to single cells in microfluidic devices demonstrated the ultimate miniaturization and accuracy of ReSeq-binding assays even at low receptor-expression levels. We expect our approach to be of generic importance for functional screening of compounds or membrane receptors, and for the detailed characterization of rare primary cells.
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Affiliation(s)
- Christoph Schreiter
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratoire de Chimie Physique des Polymères et Membranes, 1015 Lausanne, Switzerland
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Capelle MAH, Gurny R, Arvinte T. High throughput screening of protein formulation stability: practical considerations. Eur J Pharm Biopharm 2006; 65:131-48. [PMID: 17107777 DOI: 10.1016/j.ejpb.2006.09.009] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2006] [Revised: 09/01/2006] [Accepted: 09/18/2006] [Indexed: 11/28/2022]
Abstract
The formulation of protein drugs is a difficult and time-consuming process, mainly due to the complexity of protein structure and the very specific physical and chemical properties involved. Understanding protein degradation pathways is essential for the success of a biopharmaceutical drug. The present review concerns the application of high throughput screening techniques in protein formulation development. A protein high throughput formulation (HTF) platform is based on the use of microplates. Basically, the HTF platform consists of two parts: (i) sample preparation and (ii) sample analysis. Sample preparation involves automated systems for dispensing the drug and the formulation ingredients in both liquid and powder form. The sample analysis involves specific methods developed for each protein to investigate physical and chemical properties of the formulations in microplates. Examples are presented of the use of protein intrinsic fluorescence for the analysis of protein aqueous properties (e.g., conformation and aggregation). Different techniques suitable for HTF analysis are discussed and some of the issues concerning implementation are presented with reference to the use of microplates.
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Affiliation(s)
- Martinus A H Capelle
- Department of Pharmaceutics and Biopharmaceutics, University of Geneva, University of Lausanne, CH-1211 Geneva 4, Switzerland
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Citovsky V, Lee LY, Vyas S, Glick E, Chen MH, Vainstein A, Gafni Y, Gelvin SB, Tzfira T. Subcellular localization of interacting proteins by bimolecular fluorescence complementation in planta. J Mol Biol 2006; 362:1120-31. [PMID: 16949607 DOI: 10.1016/j.jmb.2006.08.017] [Citation(s) in RCA: 282] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2006] [Revised: 08/03/2006] [Accepted: 08/03/2006] [Indexed: 11/18/2022]
Abstract
Bimolecular fluorescence complementation (BiFC) represents one of the most advanced and powerful tools for studying and visualizing protein-protein interactions in living cells. In this method, putative interacting protein partners are fused to complementary non-fluorescent fragments of an autofluorescent protein, such as the yellow spectral variant of the green fluorescent protein. Interaction of the test proteins may result in reconstruction of fluorescence if the two portions of yellow spectral variant of the green fluorescent protein are brought together in such a way that they can fold properly. BiFC provides an assay for detection of protein-protein interactions, and for the subcellular localization of the interacting protein partners. To facilitate the application of BiFC to plant research, we designed a series of vectors for easy construction of N-terminal and C-terminal fusions of the target protein to the yellow spectral variant of the green fluorescent protein fragments. These vectors carry constitutive expression cassettes with an expanded multi-cloning site. In addition, these vectors facilitate the assembly of BiFC expression cassettes into Agrobacterium multi-gene expression binary plasmids for co-expression of interacting partners and additional autofluorescent proteins that may serve as internal transformation controls and markers of subcellular compartments. We demonstrate the utility of these vectors for the analysis of specific protein-protein interactions in various cellular compartments, including the nucleus, plasmodesmata, and chloroplasts of different plant species and cell types.
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Affiliation(s)
- Vitaly Citovsky
- Department of Biochemistry and Cell Biology, State University of New York, Stony Brook, NY 11794-5215, USA
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Wiedenmann J, Nienhaus GU. Live-cell imaging with EosFP and other photoactivatable marker proteins of the GFP family. Expert Rev Proteomics 2006; 3:361-74. [PMID: 16771707 DOI: 10.1586/14789450.3.3.361] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Fluorescent proteins from the green fluorescent protein family have become indispensable imaging tools for cell biology. A wide variety of these proteins were discovered in nonbioluminescent anthozoa in recent years. Some of them feature exciting new properties, with the possibility to alter their intensity and/or fluorescence color by irradiation with light of specific wavelengths. Fluorescent highlighter proteins enable many interesting applications based on regional optical marking in live cells and tissues. This review provides an overview of photoactivatable marker proteins, with a focus on EosFP, a protein that can be switched from green to red fluorescence by approximately 400-nm light. A variety of applications are presented to illustrate the versatility of EosFP in live-cell imaging.
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Affiliation(s)
- Jörg Wiedenmann
- University of Ulm, Department of General Zoology & Endocrinology, 89069 Ulm, Germany.
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