1
|
Sun N, Jia Y, Bai S, Li Q, Dai L, Li J. The power of super-resolution microscopy in modern biomedical science. Adv Colloid Interface Sci 2023; 314:102880. [PMID: 36965225 DOI: 10.1016/j.cis.2023.102880] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 03/08/2023] [Accepted: 03/08/2023] [Indexed: 03/14/2023]
Abstract
Super-resolution microscopy (SRM) technology that breaks the diffraction limit has revolutionized the field of cell biology since its appearance, which enables researchers to visualize cellular structures with nanometric resolution, multiple colors and single-molecule sensitivity. With the flourishing development of hardware and the availability of novel fluorescent probes, the impact of SRM has already gone beyond cell biology and extended to nanomedicine, material science and nanotechnology, and remarkably boosted important breakthroughs in these fields. In this review, we will mainly highlight the power of SRM in modern biomedical science, discussing how these SRM techniques revolutionize the way we understand cell structures, biomaterials assembly and how assembled biomaterials interact with cellular organelles, and finally their promotion to the clinical pre-diagnosis. Moreover, we also provide an outlook on the current technical challenges and future improvement direction of SRM. We hope this review can provide useful information, inspire new ideas and propel the development both from the perspective of SRM techniques and from the perspective of SRM's applications.
Collapse
Affiliation(s)
- Nan Sun
- Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Key Lab of Colloid, Interface and Chemical Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049
| | - Yi Jia
- Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Key Lab of Colloid, Interface and Chemical Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
| | - Shiwei Bai
- Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Key Lab of Colloid, Interface and Chemical Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049
| | - Qi Li
- State Key Laboratory of Biochemical Engineering Institute of Process Engineering Chinese Academy of Sciences, Beijing 100190, China
| | - Luru Dai
- Wenzhou Institute and Wenzhou Key Laboratory of Biophysics, University of Chinese Academy of Sciences, Wenzhou, Zhejiang 325001, China
| | - Junbai Li
- Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Key Lab of Colloid, Interface and Chemical Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049.
| |
Collapse
|
2
|
Abstract
Fluorescence imaging techniques play a pivotal role in our understanding of the nervous system. The emergence of various super-resolution microscopy methods and specialized fluorescent probes enables direct insight into neuronal structure and protein arrangements in cellular subcompartments with so far unmatched resolution. Super-resolving visualization techniques in neurons unveil a novel understanding of cytoskeletal composition, distribution, motility, and signaling of membrane proteins, subsynaptic structure and function, and neuron-glia interaction. Well-defined molecular targets in autoimmune and neurodegenerative disease models provide excellent starting points for in-depth investigation of disease pathophysiology using novel and innovative imaging methodology. Application of super-resolution microscopy in human brain samples and for testing clinical biomarkers is still in its infancy but opens new opportunities for translational research in neurology and neuroscience. In this review, we describe how super-resolving microscopy has improved our understanding of neuronal and brain function and dysfunction in the last two decades.
Collapse
Affiliation(s)
- Christian Werner
- Department of Biotechnology & Biophysics, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Markus Sauer
- Department of Biotechnology & Biophysics, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Christian Geis
- Section Translational Neuroimmunology, Department of Neurology, Jena University Hospital, Am Klinikum 1, 07747 Jena, Germany
| |
Collapse
|
3
|
Cryo-electron tomography provides topological insights into mutant huntingtin exon 1 and polyQ aggregates. Commun Biol 2021; 4:849. [PMID: 34239038 PMCID: PMC8266869 DOI: 10.1038/s42003-021-02360-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 06/15/2021] [Indexed: 01/27/2023] Open
Abstract
Huntington disease (HD) is a neurodegenerative trinucleotide repeat disorder caused by an expanded poly-glutamine (polyQ) tract in the mutant huntingtin (mHTT) protein. The formation and topology of filamentous mHTT inclusions in the brain (hallmarks of HD implicated in neurotoxicity) remain elusive. Using cryo-electron tomography and subtomogram averaging, here we show that mHTT exon 1 and polyQ-only aggregates in vitro are structurally heterogenous and filamentous, similar to prior observations with other methods. Yet, we find filaments in both types of aggregates under ~2 nm in width, thinner than previously reported, and regions forming large sheets. In addition, our data show a prevalent subpopulation of filaments exhibiting a lumpy slab morphology in both aggregates, supportive of the polyQ core model. This provides a basis for future cryoET studies of various aggregated mHTT and polyQ constructs to improve their structure-based modeling as well as their identification in cells without fusion tags.
Collapse
|
4
|
Miranda A, Gómez-Varela AI, Stylianou A, Hirvonen LM, Sánchez H, De Beule PAA. How did correlative atomic force microscopy and super-resolution microscopy evolve in the quest for unravelling enigmas in biology? NANOSCALE 2021; 13:2082-2099. [PMID: 33346312 DOI: 10.1039/d0nr07203f] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
With the invention of the Atomic Force Microscope (AFM) in 1986 and the subsequent developments in liquid imaging and cellular imaging it became possible to study the topography of cellular specimens under nearly physiological conditions with nanometric resolution. The application of AFM to biological research was further expanded with the technological advances in imaging modes where topographical data can be combined with nanomechanical measurements, offering the possibility to retrieve the biophysical properties of tissues, cells, fibrous components and biomolecules. Meanwhile, the quest for breaking the Abbe diffraction limit restricting microscopic resolution led to the development of super-resolution fluorescence microscopy techniques that brought the resolution of the light microscope comparable to the resolution obtained by AFM. The instrumental combination of AFM and optical microscopy techniques has evolved over the last decades from integration of AFM with bright-field and phase-contrast imaging techniques at first to correlative AFM and wide-field fluorescence systems and then further to the combination of AFM and fluorescence based super-resolution microscopy modalities. Motivated by the many developments made over the last decade, we provide here a review on AFM combined with super-resolution fluorescence microscopy techniques and how they can be applied for expanding our understanding of biological processes.
Collapse
Affiliation(s)
- Adelaide Miranda
- International Iberian Nanotechnology Laboratory, Avenida Mestre José Veiga s/n, Braga, Portugal.
| | - Ana I Gómez-Varela
- International Iberian Nanotechnology Laboratory, Avenida Mestre José Veiga s/n, Braga, Portugal. and Department of Applied Physics, University of Santiago de Compostela, E-15782, Santiago de Compostela, Spain.
| | - Andreas Stylianou
- Cancer Biophysics Laboratory, University of Cyprus, Nicosia, Cyprus and School of Sciences, European University Cyprus, Nicosia, Cyprus
| | - Liisa M Hirvonen
- Centre for Microscopy, Characterisation and Analysis (CMCA), The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia
| | - Humberto Sánchez
- Faculty of Applied Sciences, Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, 2629 HZ, Delft, The Netherlands
| | - Pieter A A De Beule
- International Iberian Nanotechnology Laboratory, Avenida Mestre José Veiga s/n, Braga, Portugal.
| |
Collapse
|
5
|
Boatz JC, Piretra T, Lasorsa A, Matlahov I, Conway JF, van der Wel PCA. Protofilament Structure and Supramolecular Polymorphism of Aggregated Mutant Huntingtin Exon 1. J Mol Biol 2020; 432:4722-4744. [PMID: 32598938 DOI: 10.1016/j.jmb.2020.06.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 06/01/2020] [Accepted: 06/18/2020] [Indexed: 12/11/2022]
Abstract
Huntington's disease is a progressive neurodegenerative disease caused by expansion of the polyglutamine domain in the first exon of huntingtin (HttEx1). The extent of expansion correlates with disease progression and formation of amyloid-like protein deposits within the brain. The latter display polymorphism at the microscopic level, both in cerebral tissue and in vitro. Such polymorphism can dramatically influence cytotoxicity, leading to much interest in the conditions and mechanisms that dictate the formation of polymorphs. We examine conditions that govern HttEx1 polymorphism in vitro, including concentration and the role of the non-polyglutamine flanking domains. Using electron microscopy, we observe polymorphs that differ in width and tendency for higher-order bundling. Strikingly, aggregation yields different polymorphs at low and high concentrations. Narrow filaments dominate at low concentrations that may be more relevant in vivo. We dissect the role of N- and C-terminal flanking domains using protein with the former (httNT or N17) largely removed. The truncated protein is generated by trypsin cleavage of soluble HttEx1 fusion protein, which we analyze in some detail. Dye binding and solid-state NMR studies reveal changes in fibril surface characteristics and flanking domain mobility. Higher-order interactions appear facilitated by the C-terminal tail, while the polyglutamine forms an amyloid core resembling those of other polyglutamine deposits. Fibril-surface-mediated branching, previously attributed to secondary nucleation, is reduced in absence of httNT. A new model for the architecture of the HttEx1 filaments is presented and discussed in context of the assembly mechanism and biological activity.
Collapse
Affiliation(s)
- Jennifer C Boatz
- Department of Structural Biology, School of Medicine, University of Pittsburgh, 3501 5th Ave, Biomedical Science Tower 3, Pittsburgh, PA 15213, USA.
| | - Talia Piretra
- Department of Structural Biology, School of Medicine, University of Pittsburgh, 3501 5th Ave, Biomedical Science Tower 3, Pittsburgh, PA 15213, USA.
| | - Alessia Lasorsa
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747, AG, Groningen, the Netherlands.
| | - Irina Matlahov
- Department of Structural Biology, School of Medicine, University of Pittsburgh, 3501 5th Ave, Biomedical Science Tower 3, Pittsburgh, PA 15213, USA; Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747, AG, Groningen, the Netherlands.
| | - James F Conway
- Department of Structural Biology, School of Medicine, University of Pittsburgh, 3501 5th Ave, Biomedical Science Tower 3, Pittsburgh, PA 15213, USA.
| | - Patrick C A van der Wel
- Department of Structural Biology, School of Medicine, University of Pittsburgh, 3501 5th Ave, Biomedical Science Tower 3, Pittsburgh, PA 15213, USA; Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747, AG, Groningen, the Netherlands.
| |
Collapse
|
6
|
Höppener C, Schacher FH, Deckert V. Multimodal Characterization of Resin Embedded and Sliced Polymer Nanoparticles by Means of Tip-Enhanced Raman Spectroscopy and Force-Distance Curve Based Atomic Force Microscopy. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e1907418. [PMID: 32227438 DOI: 10.1002/smll.201907418] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 01/27/2020] [Indexed: 05/24/2023]
Abstract
Understanding the property-function relation of nanoparticles in various application fields involves determining their physicochemical properties, which is still a remaining challenge to date. While a multitude of different characterization tools can be applied, these methods by themselves can only provide an incomplete picture. Therefore, novel analytical techniques are required, which can address both chemical functionality and provide structural information at the same time with high spatial resolution. This is possible by using tip-enhanced Raman spectroscopy (TERS), but due to its limited depth information, TERS is usually restricted to investigations of the nanoparticle surface. Here, TERS experiments are established on polystyrene nanoparticles (PS NPs) after resin embedding and microtome slicing. With that, unique access to their internal morphological features is gained, and thus, enables differentiation between information obtained for core- and shell-regions. Complementary information is obtained by means of transmission electron microscopy (TEM) and from force-distance curve based atomic force microscopy (FD-AFM). This multimodal approach achieves a high degree of discrimination between the resin and the polymers used for nanoparticle formulation. The high potential of TERS combined with advanced AFM spectroscopy tools to probe the mechanical properties is applied for quality control of the resin embedding procedure.
Collapse
Affiliation(s)
- Christiane Höppener
- Leibniz Institute of Photonic Technologies (IPHT) Jena, Albert-Einsteinstraße 9, 07745, Jena, Germany
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-Universität Jena, Lessingstraße 10, D-07743, Jena, Germany
| | - Felix H Schacher
- Institute of Organic Chemistry and Macromolecular Chemistry (IOMC), Friedrich-Schiller-University Jena, Lessingstraße 8, D-07743, Jena, Germany
- Jena Center for Soft Matter (JCSM), Friedrich-Schiller-University Jena, Philosophenweg 7, D-07743, Jena, Germany
| | - Volker Deckert
- Leibniz Institute of Photonic Technologies (IPHT) Jena, Albert-Einsteinstraße 9, 07745, Jena, Germany
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-Universität Jena, Lessingstraße 10, D-07743, Jena, Germany
- Institute of Quantum Science and Engineering, Texas A&M University, College Station, TX, 77843-4242, USA
| |
Collapse
|
7
|
Laidou S, Alanis-Lobato G, Pribyl J, Raskó T, Tichy B, Mikulasek K, Tsagiopoulou M, Oppelt J, Kastrinaki G, Lefaki M, Singh M, Zink A, Chondrogianni N, Psomopoulos F, Prigione A, Ivics Z, Pospisilova S, Skladal P, Izsvák Z, Andrade-Navarro MA, Petrakis S. Nuclear inclusions of pathogenic ataxin-1 induce oxidative stress and perturb the protein synthesis machinery. Redox Biol 2020; 32:101458. [PMID: 32145456 PMCID: PMC7058924 DOI: 10.1016/j.redox.2020.101458] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 01/29/2020] [Accepted: 02/06/2020] [Indexed: 12/20/2022] Open
Abstract
Spinocerebellar ataxia type-1 (SCA1) is caused by an abnormally expanded polyglutamine (polyQ) tract in ataxin-1. These expansions are responsible for protein misfolding and self-assembly into intranuclear inclusion bodies (IIBs) that are somehow linked to neuronal death. However, owing to lack of a suitable cellular model, the downstream consequences of IIB formation are yet to be resolved. Here, we describe a nuclear protein aggregation model of pathogenic human ataxin-1 and characterize IIB effects. Using an inducible Sleeping Beauty transposon system, we overexpressed the ATXN1(Q82) gene in human mesenchymal stem cells that are resistant to the early cytotoxic effects caused by the expression of the mutant protein. We characterized the structure and the protein composition of insoluble polyQ IIBs which gradually occupy the nuclei and are responsible for the generation of reactive oxygen species. In response to their formation, our transcriptome analysis reveals a cerebellum-specific perturbed protein interaction network, primarily affecting protein synthesis. We propose that insoluble polyQ IIBs cause oxidative and nucleolar stress and affect the assembly of the ribosome by capturing or down-regulating essential components. The inducible cell system can be utilized to decipher the cellular consequences of polyQ protein aggregation. Our strategy provides a broadly applicable methodology for studying polyQ diseases.
Collapse
Affiliation(s)
- Stamatia Laidou
- Institute of Applied Biosciences/Centre for Research and Technology Hellas, 57001, Thessaloniki, Greece
| | - Gregorio Alanis-Lobato
- Faculty of Biology, Johannes Gutenberg University Mainz, 55122, Mainz, Germany; Human Embryo and Stem Cell Laboratory, The Francis Crick Institute, NW1 1AT, London, UK
| | - Jan Pribyl
- Central European Institute of Technology, Masaryk University, 62500, Brno, Czech Republic
| | - Tamás Raskó
- Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, 13125, Germany
| | - Boris Tichy
- Central European Institute of Technology, Masaryk University, 62500, Brno, Czech Republic
| | - Kamil Mikulasek
- Central European Institute of Technology, Masaryk University, 62500, Brno, Czech Republic; National Centre for Biomolecular Research, Faculty of Science, Masaryk University, 62500, Brno, Czech Republic
| | - Maria Tsagiopoulou
- Institute of Applied Biosciences/Centre for Research and Technology Hellas, 57001, Thessaloniki, Greece
| | - Jan Oppelt
- Central European Institute of Technology, Masaryk University, 62500, Brno, Czech Republic
| | - Georgia Kastrinaki
- Aerosol and Particle Technology Laboratory/Chemical Process & Energy Resources Institute/Centre for Research and Technology Hellas, 57001, Thessaloniki, Greece
| | - Maria Lefaki
- Institute of Biology, Medicinal Chemistry & Biotechnology/National Hellenic Research Foundation, 11365, Athens, Greece
| | - Manvendra Singh
- Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, 13125, Germany
| | - Annika Zink
- Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, 13125, Germany; Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children's Hospital, Heinrich Heine University, 40225, Düsseldorf, Germany
| | - Niki Chondrogianni
- Institute of Biology, Medicinal Chemistry & Biotechnology/National Hellenic Research Foundation, 11365, Athens, Greece
| | - Fotis Psomopoulos
- Institute of Applied Biosciences/Centre for Research and Technology Hellas, 57001, Thessaloniki, Greece; Department of Molecular Medicine and Surgery, Karolinska Institutet, 17177, Stockholm, Sweden
| | - Alessandro Prigione
- Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, 13125, Germany; Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children's Hospital, Heinrich Heine University, 40225, Düsseldorf, Germany
| | - Zoltán Ivics
- Division of Medical Biotechnology, Paul-Ehrlich-Institute, 63225, Langen, Germany
| | - Sarka Pospisilova
- Central European Institute of Technology, Masaryk University, 62500, Brno, Czech Republic
| | - Petr Skladal
- Central European Institute of Technology, Masaryk University, 62500, Brno, Czech Republic
| | - Zsuzsanna Izsvák
- Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, 13125, Germany.
| | | | - Spyros Petrakis
- Institute of Applied Biosciences/Centre for Research and Technology Hellas, 57001, Thessaloniki, Greece.
| |
Collapse
|
8
|
Aliyan A, Cook NP, Martí AA. Interrogating Amyloid Aggregates using Fluorescent Probes. Chem Rev 2019; 119:11819-11856. [DOI: 10.1021/acs.chemrev.9b00404] [Citation(s) in RCA: 113] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Amir Aliyan
- Pasargad Institute for Advanced Innovative Solutions (PIAIS), Tehran, Iran 1991633361
- Khatam University, Tehran, Iran 1991633356
| | - Nathan P. Cook
- Department of Chemistry, Williams College, Williamstown, Massachusetts 01267, United States
| | | |
Collapse
|
9
|
Boott CE, Leitao EM, Hayward DW, Laine RF, Mahou P, Guerin G, Winnik MA, Richardson RM, Kaminski CF, Whittell GR, Manners I. Probing the Growth Kinetics for the Formation of Uniform 1D Block Copolymer Nanoparticles by Living Crystallization-Driven Self-Assembly. ACS NANO 2018; 12:8920-8933. [PMID: 30207454 DOI: 10.1021/acsnano.8b01353] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Living crystallization-driven self-assembly (CDSA) is a seeded growth method for crystallizable block copolymers (BCPs) and related amphiphiles in solution and has recently emerged as a highly promising and versatile route to uniform core-shell nanoparticles (micelles) with control of dimensions and architecture. However, the factors that influence the rate of nanoparticle growth have not been systematically studied. Using transmission electron microscopy, small- and wide-angle X-ray scattering, and super-resolution fluorescence microscopy techniques, we have investigated the kinetics of the seeded growth of poly(ferrocenyldimethylsilane)- b-(polydimethylsiloxane) (PFS- b-PDMS), as a model living CDSA system for those employing, for example, crystallizable emissive and biocompatible polymers. By altering various self-assembly parameters including concentration, temperature, solvent, and BCP composition our results have established that the time taken to prepare fiber-like micelles via the living CDSA method can be reduced by decreasing temperature, by employing solvents that are poorer for the crystallizable PFS core-forming block, and by increasing the length of the PFS core-forming block. These results are of general importance for the future optimization of a wide variety of living CDSA systems. Our studies also demonstrate that the growth kinetics for living CDSA do not exhibit the first-order dependence of growth rate on unimer concentration anticipated by analogy with living covalent polymerizations of molecular monomers. This difference may be caused by the combined influence of chain conformational effects of the BCP on addition to the seed termini and chain length dispersity.
Collapse
Affiliation(s)
- Charlotte E Boott
- School of Chemistry , University of Bristol , Cantock's Close , Bristol , BS8 1TS , U.K
| | - Erin M Leitao
- School of Chemistry , University of Bristol , Cantock's Close , Bristol , BS8 1TS , U.K
- School of Chemical Sciences , University of Auckland , 23 Symonds Street , Auckland , 1010 , New Zealand
| | - Dominic W Hayward
- School of Chemistry , University of Bristol , Cantock's Close , Bristol , BS8 1TS , U.K
| | - Romain F Laine
- Department of Chemical Engineering and Biotechnology , University of Cambridge , Philippa Fawcett Drive , Cambridge , CB3 0AS , U.K
| | - Pierre Mahou
- Department of Chemical Engineering and Biotechnology , University of Cambridge , Philippa Fawcett Drive , Cambridge , CB3 0AS , U.K
| | - Gerald Guerin
- Chemistry Department , University of Toronto , 80 St. George Street , Toronto , M5S 3H6 , Canada
| | - Mitchell A Winnik
- Chemistry Department , University of Toronto , 80 St. George Street , Toronto , M5S 3H6 , Canada
| | - Robert M Richardson
- School of Physics , University of Bristol , Tyndall Avenue , Bristol , BS8 1TL , U.K
| | - Clemens F Kaminski
- Department of Chemical Engineering and Biotechnology , University of Cambridge , Philippa Fawcett Drive , Cambridge , CB3 0AS , U.K
| | - George R Whittell
- School of Chemistry , University of Bristol , Cantock's Close , Bristol , BS8 1TS , U.K
| | - Ian Manners
- School of Chemistry , University of Bristol , Cantock's Close , Bristol , BS8 1TS , U.K
| |
Collapse
|
10
|
Reif A, Chiki A, Ricci J, Lashuel HA. Generation of Native, Untagged Huntingtin Exon1 Monomer and Fibrils Using a SUMO Fusion Strategy. J Vis Exp 2018. [PMID: 30010666 PMCID: PMC6102005 DOI: 10.3791/57506] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Huntington's Disease (HD) is an inherited fatal neurodegenerative disease caused by a CAG expansion (≥36) in the first exon of the HD gene, resulting in the expression of the Huntingtin protein (Htt) or N-terminal fragments thereof with an expanded polyglutamine (polyQ) stretch. The exon1 of the Huntingtin protein (Httex1) is the smallest Htt fragment that recapitulates many of the features of HD in cellular and animal models and is one of the most widely studied fragments of Htt. The small size of Httex1 makes it experimentally more amenable to biophysical characterization using standard and high-resolution techniques in comparison to longer fragments or full-length Htt. However, the high aggregation propensity of mutant Httex1 (mHttex1) with increased polyQ content (≥42) has made it difficult to develop efficient expression and purification systems to produce these proteins in sufficient quantities and make them accessible to scientists from different disciplines without the use of fusion proteins or other strategies that alter the native sequence of the protein. We present here a robust and optimized method for the production of milligram quantities of native, tag-free Httex1 based on the transient fusion of small ubiquitin related modifier (SUMO). The simplicity and efficiency of the strategy will eliminate the need to use non-native sequences of Httex1, thus making this protein more accessible to researchers and improving the reproducibility of experiments across different laboratories. We believe that these advances will also facilitate future studies aimed at elucidating the structure-function relationship of Htt as well as developing novel diagnostic tools and therapies to treat or slow the progression of HD.
Collapse
Affiliation(s)
- Andreas Reif
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Ecole Polytechnique Fédérale de Lausanne (EPFL)
| | - Anass Chiki
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Ecole Polytechnique Fédérale de Lausanne (EPFL)
| | - Jonathan Ricci
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Ecole Polytechnique Fédérale de Lausanne (EPFL)
| | - Hilal A Lashuel
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Ecole Polytechnique Fédérale de Lausanne (EPFL);
| |
Collapse
|
11
|
Huh H, Lee J, Kim HJ, Hohng S, Kim SK. Morphological analysis of oligomeric vs. fibrillar forms of α-synuclein aggregates with super-resolution BALM imaging. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.10.034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
12
|
Polarized super-resolution structural imaging inside amyloid fibrils using Thioflavine T. Sci Rep 2017; 7:12482. [PMID: 28970520 PMCID: PMC5624930 DOI: 10.1038/s41598-017-12864-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 09/14/2017] [Indexed: 11/08/2022] Open
Abstract
Thioflavin T (ThT) is standardly used as a fluorescent marker to detect aggregation of amyloid fibrils by conventional fluorescence microscopy, including polarization resolved imaging that brings information on the orientational order of the fibrils. These techniques are however diffraction limited and cannot provide fine structural details at the fibrils scales of 10-100 nm, which lie beyond the diffraction limit. In this work, we evaluate the capacity of ThT to photoswitch when bound to insulin amyloids by adjusting the redox properties of its environment. We demonstrate that on-off duty cycles, intensity and photostability of the ThT fluorescence emission under adequate buffer conditions permit stochastic super-resolution imaging with a localization precision close to 20 nm. We show moreover that signal to noise conditions allow polarized orientational imaging of single ThT molecules, which reveals ultra-structure signatures related to protofilaments twisting within amyloid fibrils.
Collapse
|
13
|
Adegbuyiro A, Sedighi F, Pilkington AW, Groover S, Legleiter J. Proteins Containing Expanded Polyglutamine Tracts and Neurodegenerative Disease. Biochemistry 2017; 56:1199-1217. [PMID: 28170216 DOI: 10.1021/acs.biochem.6b00936] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Several hereditary neurological and neuromuscular diseases are caused by an abnormal expansion of trinucleotide repeats. To date, there have been 10 of these trinucleotide repeat disorders associated with an expansion of the codon CAG encoding glutamine (Q). For these polyglutamine (polyQ) diseases, there is a critical threshold length of the CAG repeat required for disease, and further expansion beyond this threshold is correlated with age of onset and symptom severity. PolyQ expansion in the translated proteins promotes their self-assembly into a variety of oligomeric and fibrillar aggregate species that accumulate into the hallmark proteinaceous inclusion bodies associated with each disease. Here, we review aggregation mechanisms of proteins with expanded polyQ-tracts, structural consequences of expanded polyQ ranging from monomers to fibrillar aggregates, the impact of protein context and post-translational modifications on aggregation, and a potential role for lipid membranes in aggregation. As the pathogenic mechanisms that underlie these disorders are often classified as either a gain of toxic function or loss of normal protein function, some toxic mechanisms associated with mutant polyQ tracts will also be discussed.
Collapse
Affiliation(s)
- Adewale Adegbuyiro
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States
| | - Faezeh Sedighi
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States
| | - Albert W Pilkington
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States
| | - Sharon Groover
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States.,Blanchette Rockefeller Neurosciences Institute, Robert C. Byrd Health Sciences Center, P.O. Box 9304, West Virginia University , Morgantown, West Virginia 26506, United States.,NanoSAFE, P.O. Box 6223, West Virginia University , Morgantown, West Virginia 26506, United States
| |
Collapse
|
14
|
Hauser M, Wojcik M, Kim D, Mahmoudi M, Li W, Xu K. Correlative Super-Resolution Microscopy: New Dimensions and New Opportunities. Chem Rev 2017; 117:7428-7456. [PMID: 28045508 DOI: 10.1021/acs.chemrev.6b00604] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Correlative microscopy, the integration of two or more microscopy techniques performed on the same sample, produces results that emphasize the strengths of each technique while offsetting their individual weaknesses. Light microscopy has historically been a central method in correlative microscopy due to its widespread availability, compatibility with hydrated and live biological samples, and excellent molecular specificity through fluorescence labeling. However, conventional light microscopy can only achieve a resolution of ∼300 nm, undercutting its advantages in correlations with higher-resolution methods. The rise of super-resolution microscopy (SRM) over the past decade has drastically improved the resolution of light microscopy to ∼10 nm, thus creating exciting new opportunities and challenges for correlative microscopy. Here we review how these challenges are addressed to effectively correlate SRM with other microscopy techniques, including light microscopy, electron microscopy, cryomicroscopy, atomic force microscopy, and various forms of spectroscopy. Though we emphasize biological studies, we also discuss the application of correlative SRM to materials characterization and single-molecule reactions. Finally, we point out current limitations and discuss possible future improvements and advances. We thus demonstrate how a correlative approach adds new dimensions of information and provides new opportunities in the fast-growing field of SRM.
Collapse
Affiliation(s)
- Meghan Hauser
- Department of Chemistry, University of California , Berkeley, California 94720, United States
| | - Michal Wojcik
- Department of Chemistry, University of California , Berkeley, California 94720, United States
| | - Doory Kim
- Department of Chemistry, University of California , Berkeley, California 94720, United States
| | - Morteza Mahmoudi
- Center for Nanomedicine and Department of Anesthesiology, Brigham and Women's Hospital, Harvard Medical School , Boston, Massachusetts 02115, United States
| | - Wan Li
- Department of Chemistry, University of California , Berkeley, California 94720, United States
| | - Ke Xu
- Department of Chemistry, University of California , Berkeley, California 94720, United States.,Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| |
Collapse
|
15
|
Bondia P, Casado S, Flors C. Correlative Super-Resolution Fluorescence Imaging and Atomic Force Microscopy for the Characterization of Biological Samples. Methods Mol Biol 2017; 1663:105-113. [PMID: 28924662 DOI: 10.1007/978-1-4939-7265-4_9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Recent advances in imaging tools have greatly improved our ability to analyze the structure and molecular components of a wide range of biological systems at the nanoscale. High resolution imaging can be performed with a handful of techniques, each of them revealing particular features of the sample. A more comprehensive picture of a biological system can be achieved by combining the information provided by complementary imaging methods. Specifically, the correlation between super-resolution fluorescence imaging and atomic force microscopy (AFM) provides high resolution topography as well as specific chemical information, the latter with a spatial resolution that approaches that of AFM. We present a detailed protocol and discuss the requirements and challenges in terms of sample preparation, instrumentation, and image alignment to combine these two powerful techniques. This hybrid nanoscale imaging tool has the potential to provide robust validation for super-resolution methods as well as new insight into biological samples.
Collapse
Affiliation(s)
- Patricia Bondia
- Madrid Institute for Advanced Studies in Nanoscience (IMDEA Nanoscience) and Nanobiotechnology Unit Associated to the National Center for Biotechnology (CSIC), C/ Faraday 9, Madrid, 28049, Spain
| | - Santiago Casado
- Madrid Institute for Advanced Studies in Nanoscience (IMDEA Nanoscience) and Nanobiotechnology Unit Associated to the National Center for Biotechnology (CSIC), C/ Faraday 9, Madrid, 28049, Spain
| | - Cristina Flors
- Madrid Institute for Advanced Studies in Nanoscience (IMDEA Nanoscience) and Nanobiotechnology Unit Associated to the National Center for Biotechnology (CSIC), C/ Faraday 9, Madrid, 28049, Spain.
| |
Collapse
|
16
|
Laine RF, Kaminski Schierle GS, van de Linde S, Kaminski CF. From single-molecule spectroscopy to super-resolution imaging of the neuron: a review. Methods Appl Fluoresc 2016; 4:022004. [PMID: 28809165 PMCID: PMC5390958 DOI: 10.1088/2050-6120/4/2/022004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 05/09/2016] [Accepted: 05/19/2016] [Indexed: 12/03/2022]
Abstract
For more than 20 years, single-molecule spectroscopy has been providing invaluable insights into nature at the molecular level. The field has received a powerful boost with the development of the technique into super-resolution imaging methods, ca. 10 years ago, which overcome the limitations imposed by optical diffraction. Today, single molecule super-resolution imaging is routinely used in the study of macromolecular function and structure in the cell. Concomitantly, computational methods have been developed that provide information on numbers and positions of molecules at the nanometer-scale. In this overview, we outline the technical developments that have led to the emergence of localization microscopy techniques from single-molecule spectroscopy. We then provide a comprehensive review on the application of the technique in the field of neuroscience research.
Collapse
Affiliation(s)
- Romain F Laine
- Laser Analytics Group, Department of Chemical Engineering and Biotechnology, Cambridge University, Pembroke Street, Cambridge, CB2 3RA, UK
| | - Gabriele S Kaminski Schierle
- Laser Analytics Group, Department of Chemical Engineering and Biotechnology, Cambridge University, Pembroke Street, Cambridge, CB2 3RA, UK
| | - Sebastian van de Linde
- Department of Biotechnology and Biophysics, Julius-Maximilians-University, Am Hubland, D-97074 Würzburg, Germany
| | - Clemens F Kaminski
- Laser Analytics Group, Department of Chemical Engineering and Biotechnology, Cambridge University, Pembroke Street, Cambridge, CB2 3RA, UK
| |
Collapse
|
17
|
Schierle GSK, Michel CH, Gasparini L. Advanced imaging of tau pathology in Alzheimer Disease: New perspectives from super resolution microscopy and label-free nanoscopy. Microsc Res Tech 2016; 79:677-83. [DOI: 10.1002/jemt.22698] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 05/19/2016] [Indexed: 01/20/2023]
Affiliation(s)
- Gabriele S. Kaminski Schierle
- Department of Chemical Engineering and Biotechnology; Pembroke Street, University of Cambridge; Cambridge CB2 3RA United Kingdom
| | - Claire H. Michel
- Department of Chemical Engineering and Biotechnology; Pembroke Street, University of Cambridge; Cambridge CB2 3RA United Kingdom
| | - Laura Gasparini
- Department of Neuroscience and Brain Technologies; Istituto Italiano di Tecnologia; Via Morego 30 Genova Italy
| |
Collapse
|
18
|
Vieweg S, Ansaloni A, Wang ZM, Warner JB, Lashuel HA. An Intein-based Strategy for the Production of Tag-free Huntingtin Exon 1 Proteins Enables New Insights into the Polyglutamine Dependence of Httex1 Aggregation and Fibril Formation. J Biol Chem 2016; 291:12074-86. [PMID: 27002149 PMCID: PMC4933259 DOI: 10.1074/jbc.m116.713982] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 03/18/2016] [Indexed: 12/25/2022] Open
Abstract
The first exon of the Huntingtin protein (Httex1) is one of the most actively studied Htt fragments because its overexpression in R6/2 transgenic mice has been shown to recapitulate several key features of Huntington disease. However, the majority of biophysical studies of Httex1 are based on assessing the structure and aggregation of fusion constructs where Httex1 is fused to large proteins, such as glutathione S-transferase, maltose-binding protein, or thioredoxin, or released in solution upon in situ cleavage of these proteins. Herein, we report an intein-based strategy that allows, for the first time, the rapid and efficient production of native tag-free Httex1 with polyQ repeats ranging from 7Q to 49Q. Aggregation studies on these proteins enabled us to identify interesting polyQ-length-dependent effects on Httex1 oligomer and fibril formation that were previously not observed using Httex1 fusion proteins or Httex1 proteins produced by in situ cleavage of fusion proteins. Our studies revealed the inability of Httex1-7Q/15Q to undergo amyloid fibril formation and an inverse correlation between fibril length and polyQ repeat length, suggesting possible polyQ length-dependent differences in the structural properties of the Httex1 aggregates. Altogether, our findings underscore the importance of working with tag-free Httex1 proteins and indicate that model systems based on non-native Httex1 sequences may not accurately reproduce the effect of polyQ repeat length and solution conditions on Httex1 aggregation kinetics and structural properties.
Collapse
Affiliation(s)
- Sophie Vieweg
- From the Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland and
| | - Annalisa Ansaloni
- From the Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland and
| | - Zhe-Ming Wang
- From the Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland and
| | - John B Warner
- From the Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland and
| | - Hilal A Lashuel
- From the Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland and Qatar Biomedical Research Institute (QBRI), Hamad bin Khalifa University (HBKU), 5825 Doha, Qatar
| |
Collapse
|
19
|
Bergeron-Sandoval LP, Safaee N, Michnick S. Mechanisms and Consequences of Macromolecular Phase Separation. Cell 2016; 165:1067-1079. [DOI: 10.1016/j.cell.2016.05.026] [Citation(s) in RCA: 186] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Revised: 03/23/2016] [Accepted: 04/26/2016] [Indexed: 12/29/2022]
|
20
|
Direct Observation of α-Synuclein Amyloid Aggregates in Endocytic Vesicles of Neuroblastoma Cells. PLoS One 2016; 11:e0153020. [PMID: 27105068 PMCID: PMC4841506 DOI: 10.1371/journal.pone.0153020] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 03/21/2016] [Indexed: 11/19/2022] Open
Abstract
Aggregation of α-synuclein has been linked to both familial and sporadic Parkinson's disease. Recent studies suggest that α-synuclein aggregates may spread from cell to cell and raise questions about the propagation of neurodegeneration. While continuous progress has been made characterizing α-synuclein aggregates in vitro, there is a lack of information regarding the structure of these species inside the cells. Here, we use confocal fluorescence microscopy in combination with direct stochastic optical reconstruction microscopy, dSTORM, to investigate α-synuclein uptake when added exogenously to SH-SY5Y neuroblastoma cells, and to probe in situ morphological features of α-synuclein aggregates with near nanometer resolution. We demonstrate that using dSTORM, it is possible to follow noninvasively the uptake of extracellularly added α-synuclein aggregates by the cells. Once the aggregates are internalized, they move through the endosomal pathway and accumulate in lysosomes to be degraded. Our dSTORM data show that α-synuclein aggregates remain assembled after internalization and they are shortened as they move through the endosomal pathway. No further aggregation was observed inside the lysosomes as speculated in the literature, nor in the cytoplasm of the cells. Our study thus highlights the super-resolution capability of dSTORM to follow directly the endocytotic uptake of extracellularly added amyloid aggregates and to probe the morphology of in situ protein aggregates even when they accumulate in small vesicular compartments.
Collapse
|
21
|
Nanoscopic insights into seeding mechanisms and toxicity of α-synuclein species in neurons. Proc Natl Acad Sci U S A 2016; 113:3815-9. [PMID: 26993805 PMCID: PMC4833232 DOI: 10.1073/pnas.1516546113] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
New strategies for visualizing self-assembly processes at the nanoscale give deep insights into the molecular origins of disease. An example is the self-assembly of misfolded proteins into amyloid fibrils, which is related to a range of neurodegenerative disorders, such as Parkinson's and Alzheimer's diseases. Here, we probe the links between the mechanism of α-synuclein (AS) aggregation and its associated toxicity by using optical nanoscopy directly in a neuronal cell culture model of Parkinson's disease. Using superresolution microscopy, we show that protein fibrils are taken up by neuronal cells and act as prion-like seeds for elongation reactions that both consume endogenous AS and suppress its de novo aggregation. When AS is internalized in its monomeric form, however, it nucleates and triggers the aggregation of endogenous AS, leading to apoptosis, although there are no detectable cross-reactions between externally added and endogenous protein species. Monomer-induced apoptosis can be reduced by pretreatment with seed fibrils, suggesting that partial consumption of the externally added or excess soluble AS can be significantly neuroprotective.
Collapse
|
22
|
Whelan DR, Bell TDM. Correlative Synchrotron Fourier Transform Infrared Spectroscopy and Single Molecule Super Resolution Microscopy for the Detection of Composition and Ultrastructure Alterations in Single Cells. ACS Chem Biol 2015; 10:2874-83. [PMID: 26421635 DOI: 10.1021/acschembio.5b00754] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Single molecule localization microscopy (SMLM) and synchrotron Fourier transform infrared (S-FTIR) spectroscopy are two techniques capable of elucidating unique and valuable biological detail. SMLM provides images of the structures and distributions of targeted biomolecules at spatial resolutions up to an order of magnitude better than the diffraction limit, whereas IR spectroscopy objectively measures the holistic biochemistry of an entire sample, thereby revealing any variations in overall composition. Both tools are currently applied extensively to detect cellular response to disease, chemical treatment, and environmental change. Here, these two techniques have been applied correlatively at the single cell level to probe the biochemistry of common fixation methods and have detected various fixation-induced losses of biomolecular composition and cellular ultrastructure. Furthermore, by extensive honing and optimizing of fixation protocols, many fixation artifacts previously considered pervasive and regularly identified using IR spectroscopy and fluorescence techniques have been avoided. Both paraformaldehyde and two-step glutaraldehyde fixation were identified as best preserving biochemistry for both SMLM and IR studies while other glutaraldehyde and methanol fixation protocols were demonstrated to cause significant biochemical changes and higher variability between samples. Moreover, the potential complementarity of the two techniques was strikingly demonstrated in the correlated detection of biochemical changes as well as in the detection of fixation-induced damage that was only revealed by one of the two techniques.
Collapse
Affiliation(s)
- Donna R. Whelan
- School
of Chemistry, Monash University, Victoria, Australia, 3800
| | - Toby D. M. Bell
- School
of Chemistry, Monash University, Victoria, Australia, 3800
| |
Collapse
|
23
|
Abstract
Aberrant aggregation of improperly folded proteins is the hallmark of several human neurodegenerative disorders, including Huntington’s Disease (HD) with autosomal-dominant inheritance. In HD, expansion of the CAG-repeat-encoded polyglutamine (polyQ) stretch beyond ~40 glutamines in huntingtin (Htt) and its N-terminal fragments leads to the formation of large (up to several μm) globular neuronal inclusion bodies (IBs) over time. We report direct observations of aggregating Htt exon 1 in living and fixed cells at enhanced spatial resolution by stimulated emission depletion (STED) microscopy and single-molecule super-resolution optical imaging. Fibrils of Htt exon 1 arise abundantly across the cytosolic compartment and also in neuritic processes only after nucleation and aggregation into a fairly advanced stage of growth of the prominent IB have taken place. Structural characterizations of fibrils by STED show a distinct length cutoff at ~1·5 μm and reveal subsequent coalescence (bundling/piling). Cytosolic fibrils are observed even at late stages in the process, side-by-side with the mature IB. Htt sequestration into the IB, which in neurons has been argued to be a cell-protective phenomenon, thus appears to saturate and over-power the cellular degradation systems and leaves cells vulnerable to further aggregation producing much smaller, potentially toxic, conformational protein species of which the fibrils may be comprised. We further found that exogenous delivery of the apical domain of the chaperonin subunit CCT1 to the cells via the cell medium reduced the aggregation propensity of mutant Htt exon 1 in general, and strongly reduced the occurrence of such late-stage fibrils in particular.
Collapse
|
24
|
Moerner WEWE. Single-Molecule Spectroscopy, Imaging, and Photocontrol: Foundations for Super-Resolution Microscopy (Nobel Lecture). Angew Chem Int Ed Engl 2015. [PMID: 26088273 DOI: 10.1103/revmodphys.87.1183] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
The initial steps toward optical detection and spectroscopy of single molecules in condensed matter arose out of the study of inhomogeneously broadened optical absorption profiles of molecular impurities in solids at low temperatures. Spectral signatures relating to the fluctuations of the number of molecules in resonance led to the attainment of the single-molecule limit in 1989 using frequency-modulation laser spectroscopy. In the early 90s, many fascinating physical effects were observed for individual molecules, and the imaging of single molecules as well as observations of spectral diffusion, optical switching and the ability to select different single molecules in the same focal volume simply by tuning the pumping laser frequency provided important forerunners of the later super-resolution microscopy with single molecules. In the room temperature regime, imaging of single copies of the green fluorescent protein also uncovered surprises, especially the blinking and photoinduced recovery of emitters, which stimulated further development of photoswitchable fluorescent protein labels. Because each single fluorophore acts a light source roughly 1 nm in size, microscopic observation and localization of individual fluorophores is a key ingredient to imaging beyond the optical diffraction limit. Combining this with active control of the number of emitting molecules in the pumped volume led to the super-resolution imaging of Eric Betzig and others, a new frontier for optical microscopy beyond the diffraction limit. The background leading up to these observations is described and current developments are summarized.
Collapse
Affiliation(s)
- W E William E Moerner
- Departments of Chemistry and (by Courtesy) of Applied Physics, Stanford University, Stanford, California 94305 (USA)
| |
Collapse
|
25
|
Moerner WEWE. Spektroskopie, Visualisierung und Photomanipulation einzelner Moleküle: die Grundlage für superhochauflösende Mikroskopie (Nobel-Aufsatz). Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201501949] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
26
|
Moerner WEWE. Single-Molecule Spectroscopy, Imaging, and Photocontrol: Foundations for Super-Resolution Microscopy (Nobel Lecture). Angew Chem Int Ed Engl 2015; 54:8067-93. [PMID: 26088273 DOI: 10.1002/anie.201501949] [Citation(s) in RCA: 134] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Indexed: 11/10/2022]
Abstract
The initial steps toward optical detection and spectroscopy of single molecules in condensed matter arose out of the study of inhomogeneously broadened optical absorption profiles of molecular impurities in solids at low temperatures. Spectral signatures relating to the fluctuations of the number of molecules in resonance led to the attainment of the single-molecule limit in 1989 using frequency-modulation laser spectroscopy. In the early 90s, many fascinating physical effects were observed for individual molecules, and the imaging of single molecules as well as observations of spectral diffusion, optical switching and the ability to select different single molecules in the same focal volume simply by tuning the pumping laser frequency provided important forerunners of the later super-resolution microscopy with single molecules. In the room temperature regime, imaging of single copies of the green fluorescent protein also uncovered surprises, especially the blinking and photoinduced recovery of emitters, which stimulated further development of photoswitchable fluorescent protein labels. Because each single fluorophore acts a light source roughly 1 nm in size, microscopic observation and localization of individual fluorophores is a key ingredient to imaging beyond the optical diffraction limit. Combining this with active control of the number of emitting molecules in the pumped volume led to the super-resolution imaging of Eric Betzig and others, a new frontier for optical microscopy beyond the diffraction limit. The background leading up to these observations is described and current developments are summarized.
Collapse
Affiliation(s)
- W E William E Moerner
- Departments of Chemistry and (by Courtesy) of Applied Physics, Stanford University, Stanford, California 94305 (USA)
| |
Collapse
|
27
|
Duim WC, Jiang Y, Shen K, Frydman J, Moerner WE. Super-resolution fluorescence of huntingtin reveals growth of globular species into short fibers and coexistence of distinct aggregates. ACS Chem Biol 2014; 9:2767-78. [PMID: 25330023 PMCID: PMC4273975 DOI: 10.1021/cb500335w] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
![]()
Polyglutamine-expanded
huntingtin, the protein encoded by HTT mutations
associated with Huntington’s disease,
forms aggregate species in vitro and in vivo. Elucidation of the mechanism of growth of fibrillar aggregates
from soluble monomeric protein is critical to understanding the progression
of Huntington’s disease and to designing therapeutics for the
disease, as well as for aggregates implicated in Alzheimer’s
and Parkinson’s diseases. We used the technique of multicolor
single-molecule, super-resolution fluorescence imaging to characterize
the growth of huntingtin exon 1 aggregates. The huntingtin exon 1
aggregation followed a pathway from exclusively spherical or globular
species of ∼80 nm to fibers ∼1 μm in length that
increased in width, but not length, over time with the addition of
more huntingtin monomers. The fibers further aggregated with one another
into aggregate assemblies of increasing size. Seeds created by sonication,
which were comparable in shape and size to the globular species in
the pathway, were observed to grow through multidirectional elongation
into fibers, suggesting a mechanism for growth of globular species
into fibers. The single-molecule sensitivity of our approach made
it possible to characterize the aggregation pathway across a large
range of size scales, from monomers to fiber assemblies, and revealed
the coexistence of different aggregate species (globular species,
fibers, fiber assemblies) even at late time points.
Collapse
Affiliation(s)
- Whitney C. Duim
- Department of Chemistry, ‡Department of Applied Physics, and §Department of Biology, Stanford University, Stanford, California 94305, United States
| | - Yan Jiang
- Department of Chemistry, ‡Department of Applied Physics, and §Department of Biology, Stanford University, Stanford, California 94305, United States
| | - Koning Shen
- Department of Chemistry, ‡Department of Applied Physics, and §Department of Biology, Stanford University, Stanford, California 94305, United States
| | - Judith Frydman
- Department of Chemistry, ‡Department of Applied Physics, and §Department of Biology, Stanford University, Stanford, California 94305, United States
| | - W. E. Moerner
- Department of Chemistry, ‡Department of Applied Physics, and §Department of Biology, Stanford University, Stanford, California 94305, United States
| |
Collapse
|
28
|
Pinotsi D, Buell A, Galvagnion C, Dobson C, Kaminski Schierle GS, Kaminski CF. Direct observation of heterogeneous amyloid fibril growth kinetics via two-color super-resolution microscopy. NANO LETTERS 2014; 14:339-45. [PMID: 24303845 PMCID: PMC3901574 DOI: 10.1021/nl4041093] [Citation(s) in RCA: 135] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 11/26/2013] [Indexed: 05/18/2023]
Abstract
The self-assembly of normally soluble proteins into fibrillar amyloid structures is associated with a range of neurodegenerative disorders, such as Parkinson's and Alzheimer's diseases. In the present study, we show that specific events in the kinetics of the complex, multistep aggregation process of one such protein, α-synuclein, whose aggregation is a characteristic hallmark of Parkinson's disease, can be followed at the molecular level using optical super-resolution microscopy. We have explored in particular the elongation of preformed α-synuclein fibrils; using two-color single-molecule localization microscopy we are able to provide conclusive evidence that the elongation proceeds from both ends of the fibril seeds. Furthermore, the technique reveals a large heterogeneity in the growth rates of individual fibrils; some fibrils exhibit no detectable growth, whereas others extend to more than ten times their original length within hours. These large variations in the growth kinetics can be attributed to fibril structural polymorphism. Our technique offers new capabilities in the study of amyloid growth dynamics at the molecular level and is readily translated to the study of the self-assembly of other nanostructures.
Collapse
Affiliation(s)
- Dorothea Pinotsi
- Department of Chemical Engineering and Biotechnology and Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
- E-mail:
(D.P.)
| | - Alexander
K. Buell
- Department of Chemical Engineering and Biotechnology and Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - Celine Galvagnion
- Department of Chemical Engineering and Biotechnology and Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - Christopher
M. Dobson
- Department of Chemical Engineering and Biotechnology and Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - Gabriele S. Kaminski Schierle
- Department of Chemical Engineering and Biotechnology and Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
- E-mail:
(D.P.)
| | - Clemens F. Kaminski
- Department of Chemical Engineering and Biotechnology and Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
- E-mail:
(D.P.)
| |
Collapse
|
29
|
Monserrate A, Casado S, Flors C. Correlative Atomic Force Microscopy and Localization-Based Super-Resolution Microscopy: Revealing Labelling and Image Reconstruction Artefacts. Chemphyschem 2013; 15:647-50. [DOI: 10.1002/cphc.201300853] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Indexed: 11/10/2022]
|
30
|
Sahl SJ, Moerner WE. Super-resolution fluorescence imaging with single molecules. Curr Opin Struct Biol 2013; 23:778-87. [PMID: 23932284 PMCID: PMC3805708 DOI: 10.1016/j.sbi.2013.07.010] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 07/05/2013] [Indexed: 11/16/2022]
Abstract
The ability to detect, image and localize single molecules optically with high spatial precision by their fluorescence enables an emergent class of super-resolution microscopy methods which have overcome the longstanding diffraction barrier for far-field light-focusing optics. Achieving spatial resolutions of 20-40nm or better in both fixed and living cells, these methods are currently being established as powerful tools for minimally-invasive spatiotemporal analysis of structural details in cellular processes which benefit from enhanced resolution. Briefly covering the basic principles, this short review then summarizes key recent developments and application examples of two-dimensional and three-dimensional (3D) multi-color techniques and faster time-lapse schemes. The prospects for quantitative imaging - in terms of improved ability to correct for dipole-emission-induced systematic localization errors and to provide accurate counts of molecular copy numbers within nanoscale cellular domains - are discussed.
Collapse
Affiliation(s)
- Steffen J Sahl
- Department of Chemistry, Stanford University, Stanford, CA, USA
| | | |
Collapse
|
31
|
Ries J, Udayar V, Soragni A, Hornemann S, Nilsson KPR, Riek R, Hock C, Ewers H, Aguzzi AA, Rajendran L. Superresolution imaging of amyloid fibrils with binding-activated probes. ACS Chem Neurosci 2013; 4:1057-61. [PMID: 23594172 DOI: 10.1021/cn400091m] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Protein misfolding into amyloid-like aggregates underlies many neurodegenerative diseases. Thus, insights into the structure and function of these amyloids will provide valuable information on the pathological mechanisms involved and aid in the design of improved drugs for treating amyloid-based disorders. However, determining the structure of endogenous amyloids at high resolution has been difficult. Here we employ binding-activated localization microscopy (BALM) to acquire superresolution images of α-synuclein amyloid fibrils with unprecedented optical resolution. We propose that BALM imaging can be extended to study the structure of other amyloids, for differential diagnosis of amyloid-related diseases and for discovery of drugs that perturb amyloid structure for therapy.
Collapse
Affiliation(s)
- Jonas Ries
- EMBL Heidelberg, Cell Biology and Biophysics, Meyerhofstr.
1, 69117 Heidelberg, Germany
- ETH Zurich, Wolfgang-Pauli-Str. 10, 8093
Zurich, Switzerland
| | - Vinod Udayar
- Systems
and Cell Biology of Neurodegeneration, University of Zurich, August-Forel Str. 1, 8008, Zurich, Switzerland
- Division of Psychiatry Research, University of Zurich, August-Forel Str. 1, 8008, Zurich,
Switzerland
- Graduate program of the Zurich Neuroscience Center, University of Zurich & Graduate Program in Systems Physiology and Metabolic Diseases, ETH Zurich, Switzerland
| | - Alice Soragni
- ETH Zurich, Wolfgang-Pauli-Str. 10, 8093
Zurich, Switzerland
- UCLA-DOE, Institute for Genomics and Proteomics, 611 Charles
E. Young Dr. S., Los Angeles, California 90095-1570, United States
| | - Simone Hornemann
- Neuropathology, University of Zurich, Schmelzbergstrasse 12, 8091 Zurich,
Switzerland
| | | | - Roland Riek
- ETH Zurich, Wolfgang-Pauli-Str. 10, 8093
Zurich, Switzerland
| | - Christoph Hock
- Division of Psychiatry Research, University of Zurich, August-Forel Str. 1, 8008, Zurich,
Switzerland
| | - Helge Ewers
- ETH Zurich, Wolfgang-Pauli-Str. 10, 8093
Zurich, Switzerland
| | - Adriano A. Aguzzi
- Neuropathology, University of Zurich, Schmelzbergstrasse 12, 8091 Zurich,
Switzerland
| | - Lawrence Rajendran
- Systems
and Cell Biology of Neurodegeneration, University of Zurich, August-Forel Str. 1, 8008, Zurich, Switzerland
- Division of Psychiatry Research, University of Zurich, August-Forel Str. 1, 8008, Zurich,
Switzerland
- Graduate program of the Zurich Neuroscience Center, University of Zurich & Graduate Program in Systems Physiology and Metabolic Diseases, ETH Zurich, Switzerland
| |
Collapse
|
32
|
Lee SF, Vérolet Q, Fürstenberg A. Improved super-resolution microscopy with oxazine fluorophores in heavy water. Angew Chem Int Ed Engl 2013; 52:8948-51. [PMID: 23828815 DOI: 10.1002/anie.201302341] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Indexed: 11/12/2022]
Affiliation(s)
- Steven F Lee
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK.
| | | | | |
Collapse
|
33
|
Lee SF, Vérolet Q, Fürstenberg A. Verbesserte hochauflösende Mikroskopie mit Oxazinfarbstoffen in schwerem Wasser. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201302341] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
34
|
Cheng MC, Leske AT, Matsuoka T, Kim BC, Lee J, Burns MA, Takayama S, Biteen JS. Super-resolution imaging of PDMS nanochannels by single-molecule micelle-assisted blink microscopy. J Phys Chem B 2013; 117:4406-11. [PMID: 23256598 DOI: 10.1021/jp307635v] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Single-molecule super-resolution microscopy is an emerging technique for nanometer-scale fluorescence imaging, but in vitro single-molecule imaging protocols typically require a constant supply of reagents, and such transport is restricted in constrained geometries. In this article, we develop single-molecule micelle-assisted blink (MAB) microcopy to enable subdiffraction-limit imaging of nanochannels with better than 40 nm accuracy. The method, based on micelles and thiol-related photoswitching, is used to measure nanochannels formed in polydimethylsiloxane through tensile cracking. These conduits are reversibly size-adjustable from a few nanometers up to a micrometer and enable filtering of small particles and linearization of DNA. Unfortunately, conventional techniques cannot be used to measure widths, characterize heterogeneities, or discover porosity in situ. We overcome the access barriers by using sodium dodecyl sulfate (SDS), an ionic surfactant, to facilitate delivery of Cy5 dye and β-mercaptoethanol reducing agent in the confined geometry. These SDS micelles and admicelles have the further benefit of slowing diffusion of Cy5 to improve localization accuracy. We use MAB microscopy to measure nanochannel widths, to reveal heterogeneity along channel lengths and between different channels in the same device, and to probe biologically relevant information about the nanoenvironment, such as solvent accessibility.
Collapse
Affiliation(s)
- Mou-Chi Cheng
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
| | | | | | | | | | | | | | | |
Collapse
|
35
|
Yip CM. Correlative optical and scanning probe microscopies for mapping interactions at membranes. Methods Mol Biol 2013; 950:439-56. [PMID: 23086889 DOI: 10.1007/978-1-62703-137-0_24] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Innovative approaches for real-time imaging on molecular-length scales are providing researchers with powerful strategies for characterizing molecular and cellular structures and dynamics. Combinatorial techniques that integrate two or more distinct imaging modalities are particularly compelling as they provide a means for overcoming the limitations of the individual modalities and, when applied simultaneously, enable the collection of rich multi-modal datasets. Almost since its inception, scanning probe microscopy has closely associated with optical microscopy. This is particularly evident in the fields of cellular and molecular biophysics where researchers are taking full advantage of these real-time, in situ, tools to acquire three-dimensional molecular-scale topographical images with nanometer resolution, while simultaneously characterizing their structure and interactions though conventional optical microscopy. The ability to apply mechanical or optical stimuli provides an additional experimental dimension that has shown tremendous promise for examining dynamic events on sub-cellular length scales. In this chapter, we describe recent efforts in developing these integrated platforms, the methodology for, and inherent challenges in, performing coupled imaging experiments, and the potential and future opportunities of these research tools for the fields of molecular and cellular biophysics with a specific emphasis on the application of these coupled approaches for the characterization of interactions occurring at membrane interfaces.
Collapse
Affiliation(s)
- Christopher M Yip
- Department of Chemical Engineering and Applied Chemistry, Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada.
| |
Collapse
|
36
|
Super-resolution fluorescence imaging of intracellular mutant huntingtin protein reveals a population of fibrillar aggregates co-existing with compact perinuclear inclusion bodies. Mol Neurodegener 2013. [PMCID: PMC3847101 DOI: 10.1186/1750-1326-8-s1-o18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
|
37
|
Abstract
The identities of toxic aggregate species in Huntington's disease pathogenesis remain ambiguous. While polyQ-expanded huntingtin (Htt) is known to accumulate in compact inclusion bodies inside neurons, this is widely thought to be a protective coping response that sequesters misfolded conformations or aggregated states of the mutated protein. To define the spatial distributions of fluorescently-labeled Htt-exon1 species in the cell model PC12m, we employed highly sensitive single-molecule super-resolution fluorescence imaging. In addition to inclusion bodies and the diffuse pool of monomers and oligomers, fibrillar aggregates -100 nm in diameter and up to -1-2 µm in length were observed for pathogenic polyQ tracts (46 and 97 repeats) after targeted photo-bleaching of the inclusion bodies. These short structures bear a striking resemblance to fibers described in vitro. Definition of the diverse Htt structures in cells will provide an avenue to link the impact of therapeutic agents to aggregate populations and morphologies.
Collapse
|
38
|
Super-resolution fluorescence imaging with blink microscopy. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2012. [PMID: 23086873 DOI: 10.1007/978-1-62703-137-0_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
Recently, a new approach for super-resolution microscopy has emerged which is based on the successive localization of single molecules. The majority of molecules are prepared to reside in a nonfluorescent dark state, leaving only a few single molecules fluorescing. The single molecules can subsequently be localized on the camera image. Successive localization of all molecules allows reconstruction of a super-resolved image of the labeled structure. A variety of ways for limiting the number of locatable molecules have been developed recently which expand this current field of imaging. Here we describe a super-resolution microscopy method that employs the use of reversible, generic dark states, for example radical ion states. This method requires only a single laser source and can be carried out with many fluorescent dyes, in some cases, even in living cells. We provide a step-by-step procedure for this method, which we have called Blink Microscopy.
Collapse
|
39
|
Roberti MJ, Fölling J, Celej MS, Bossi M, Jovin TM, Jares-Erijman EA. Imaging nanometer-sized α-synuclein aggregates by superresolution fluorescence localization microscopy. Biophys J 2012; 102:1598-607. [PMID: 22500760 DOI: 10.1016/j.bpj.2012.03.010] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Revised: 02/27/2012] [Accepted: 03/02/2012] [Indexed: 02/04/2023] Open
Abstract
The morphological features of α-synuclein (AS) amyloid aggregation in vitro and in cells were elucidated at the nanoscale by far-field subdiffraction fluorescence localization microscopy. Labeling AS with rhodamine spiroamide probes allowed us to image AS fibrillar structures by fluorescence stochastic nanoscopy with an enhanced resolution at least 10-fold higher than that achieved with conventional, diffraction-limited techniques. The implementation of dual-color detection, combined with atomic force microscopy, revealed the propagation of individual fibrils in vitro. In cells, labeled protein appeared as amyloid aggregates of spheroidal morphology and subdiffraction sizes compatible with in vitro supramolecular intermediates perceived independently by atomic force microscopy and cryo-electron tomography. We estimated the number of monomeric protein units present in these minute structures. This approach is ideally suited for the investigation of the molecular mechanisms of amyloid formation both in vitro and in the cellular milieu.
Collapse
Affiliation(s)
- M Julia Roberti
- Departamento de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina
| | | | | | | | | | | |
Collapse
|
40
|
Cordes T, Vogelsang J, Steinhauer C, Stein IH, Forthmann C, Gietl A, Schmied JJ, Acuna GP, Laurien S, Lalkens B, Tinnefeld P. Far-Field Nanoscopy with Conventional Fluorophores: Photostability, Photophysics, and Transient Binding. SPRINGER SERIES ON FLUORESCENCE 2012. [DOI: 10.1007/4243_2012_40] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
|