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https://www.readbyqxmd.com/read/28536263/axodendritic-sorting-and-pathological-missorting-of-tau-is-isoform-specific-and-determined-by-axon-initial-segment-architecture
#1
Hans Zempel, Frank Dennissen, Yatender Kumar, Julia Luedtke, Jacek Biernat, Eva-Maria Mandelkow, Eckhard Mandelkow
Subcellular mislocalization of the microtubule-associated protein Tau is a hallmark of Alzheimer disease (AD) and other tauopathies. Six Tau isoforms, differentiated by the presence or absence of a second repeat or of N-terminal inserts, exist in the human CNS but their physiological and pathological differences have long remained remain elusive. Here, we investigated the properties and distributions of human and rodent Tau isoforms in primary forebrain rodent neurons. We found that the Tau-Diffusion-Barrier (TDB), located within the Axon-Initial-Segment (AIS), controls retrograde (axon-to-soma) and anterograde (soma-to-axon) traffic of Tau...
May 23, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28507079/distance-constraints-on-activation-of-trpv4-channels-by-akap150-bound-pkc%C3%AE-in-arterial-myocytes
#2
Sendoa Tajada, Claudia M Moreno, Samantha O'Dwyer, Sean Woods, Daisuke Sato, Manuel F Navedo, L Fernando Santana
TRPV4 (transient receptor potential vanilloid 4) channels are Ca(2+)-permeable channels that play a key role in regulating vascular tone. In arterial myocytes, opening of TRPV4 channels creates local increases in Ca(2+) influx, detectable optically as "TRPV4 sparklets." TRPV4 sparklet activity can be enhanced by the action of the vasoconstrictor angiotensin II (AngII). This modulation depends on the activation of subcellular signaling domains that comprise protein kinase C α (PKCα) bound to the anchoring protein AKAP150...
May 15, 2017: Journal of General Physiology
https://www.readbyqxmd.com/read/28495024/live-cell-nanoscopy-in-antiadhesion-therapy
#3
Joan A Geoghegan, Timothy J Foster, Pietro Speziale, Yves F Dufrêne
Live-cell nanoscopy has contributed significantly to assessing the inhibition of adhesion of uropathogenic Escherichia coli and Staphylococcus aureus by glycoconjugates and monoclonal antibodies, respectively, and of S. aureus surface attachment and cell-cell association by a synthetic peptide. This new technology shows promise for the development of antiadhesion therapies against bacterial pathogens.
May 8, 2017: Trends in Microbiology
https://www.readbyqxmd.com/read/28466025/review-of-combined-isotopic-and-optical-nanoscopy
#4
REVIEW
Katharina N Richter, Silvio O Rizzoli, Sebastian Jähne, Angela Vogts, Jelena Lovric
Investigating the detailed substructure of the cell is beyond the ability of conventional optical microscopy. Electron microscopy, therefore, has been the only option for such studies for several decades. The recent implementation of several super-resolution optical microscopy techniques has rendered the investigation of cellular substructure easier and more efficient. Nevertheless, optical microscopy only provides an image of the present structure of the cell, without any information on its long-temporal changes...
April 2017: Neurophotonics
https://www.readbyqxmd.com/read/28463260/investigation-of-axial-and-transverse-focal-spot-sizes-of-fresnel-zone-plates
#5
Tao Liu, Qiang Liu, Shuming Yang, Zhuangde Jiang, Tong Wang, Guofeng Zhang
An axial spot size formula is given for a standard binary Fresnel zone plate (FZP) illuminated with a linearly polarized beam. The axial spot size, characterized by the full width at half-maximum (FWHM), can be accurately expressed by the Jiang-Wilson formula, viz., d<sub>z</sub>=0.9λ<sub>0</sub>/[η-(η<sup>2</sup>-NA<sup>2</sup>)<sup>1/2</sup>], when the number of transparent annuli is no less than 3. λ<sub>0</sub> is the illumination light wavelength, η is the refractive index, and NA is the equivalent numerical aperture of a FZP...
May 1, 2017: Applied Optics
https://www.readbyqxmd.com/read/28457706/a-versatile-tool-for-live-cell-imaging-and-super-resolution-nanoscopy-studies-of-hiv-1-env-distribution-and-mobility
#6
Volkan Sakin, Janina Hanne, Jessica Dunder, Maria Anders-Össwein, Vibor Laketa, Ivana Nikić, Hans-Georg Kräusslich, Edward A Lemke, Barbara Müller
The envelope glycoproteins (Env) of HIV-1 mediate cell entry through fusion of the viral envelope with a target cell membrane. Intramembrane mobility and clustering of Env trimers at the viral budding site are essential for its function. Previous live-cell and super-resolution microscopy studies were limited by lack of a functional fluorescent Env derivative, requiring antibody labeling for detection. Introduction of a bio-orthogonal amino acid by genetic code expansion, combined with click chemistry, offers novel possibilities for site-specific, minimally invasive labeling...
May 18, 2017: Cell Chemical Biology
https://www.readbyqxmd.com/read/28451345/protein-based-fluorescent-nanoparticles-for-super-resolution-sted-imaging-of-live-cells
#7
Li Shang, Peng Gao, Haixia Wang, Radian Popescu, Dagmar Gerthsen, Gerd Ulrich Nienhaus
Development of nanoparticles for super-resolution imaging (sriNPs) can greatly enrich the toolbox of robust optical probes for biological studies. Moreover, sriNPs enable us to monitor the behavior of engineered nanomaterials in complex biological environments with high spatial resolution, which is important for advancing our understanding of nano-bio interactions. Up to now, reports on sriNPs have been scarce. In this work, we report a facile strategy to prepare protein-based fluorescent NPs that can be utilized as probes in super-resolution microscopy...
March 1, 2017: Chemical Science
https://www.readbyqxmd.com/read/28445760/determining-the-spatial-relationship-of%C3%A2-membrane-bound-aquaporin-4-autoantibodies-by-sted-nanoscopy
#8
John N Soltys, Stephanie A Meyer, Hannah Schumann, Emily A Gibson, Diego Restrepo, Jeffrey L Bennett
Determining the spatial relationship of individual proteins in dense assemblies remains a challenge for superresolution nanoscopy. The organization of aquaporin-4 (AQP4) into large plasma membrane assemblies provides an opportunity to image membrane-bound AQP4 antibodies (AQP4-IgG) and evaluate changes in their spatial distribution due to alterations in AQP4 isoform expression and AQP4-IgG epitope specificity. Using stimulated emission depletion nanoscopy, we imaged secondary antibody labeling of monoclonal AQP4-IgGs with differing epitope specificity bound to isolated tetramers (M1-AQP4) and large orthogonal arrays of AQP4 (M23-AQP4)...
April 25, 2017: Biophysical Journal
https://www.readbyqxmd.com/read/28437075/fluorescent-photoswitchable-diarylethenes-for-biolabeling-and-single-molecule-localization-microscopies-with-optical-superresolution
#9
Benoît Roubinet, Michael Weber, Heydar Shojaei, Mark Bates, Mariano L Bossi, Vladimir N Belov, Masahiro Irie, Stefan W Hell
A modular assembly of water-soluble diarylethenes (DAEs), applicable as biomarkers for optical nanoscopy, is reported. Reversibly photoswitchable 1,2-bis(2-alkyl-6-phenyl-1-benzothiophene-1,1-dioxide-3-yl)perfluorocyclopentenes possessing a fluorescent "closed" form were decorated with one or two methoxy group(s) attached to the para-position(s) of phenyl ring(s) and two, four, or eight carboxylic acid groups. Antibody conjugates of these DAEs feature low aggregation, efficient photoswitching in aqueous buffers, specific staining of cellular structures, and photophysical properties (high emission efficiencies and low cycloreversion quantum yields) enabling their application in superresolution microscopy...
May 4, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28428254/a-novel-physiological-role-for-arf1-in-the-formation-of-bi-directional-tubules-from-the-golgi
#10
Francesca Bottanelli, Nicole Kilian, Andreas M Ernst, Felix Rivera-Molina, Lena K Schroeder, Emil B Kromann, Mark D Lessard, Roman S Erdmann, Alanna Schepartz, David Baddeley, Joerg Bewersdorf, Derek Toomre, James E Rothman
Capitalizing on CRISPR/Cas9 gene editing techniques and super-resolution nanoscopy, we have explored the role of the small GTPase ARF1 in mediating transport steps at the Golgi. Surprisingly, beside its well-established role in generating COPI vesicles, we find that ARF1 is additionally involved in the formation of long (∼ 3 μm), thin (∼ 110 nm diameter) tubular carriers. The anterograde and retrograde tubular carriers are both largely free of the classical Golgi coat proteins Coatomer (COPI) and Clathrin...
April 20, 2017: Molecular Biology of the Cell
https://www.readbyqxmd.com/read/28417977/multicolour-nanoscopy-of-fixed-and-living-cells-with-a-single-sted-beam-and-hyperspectral-detection
#11
Franziska R Winter, Maria Loidolt, Volker Westphal, Alexey N Butkevich, Carola Gregor, Steffen J Sahl, Stefan W Hell
The extension of fluorescence nanoscopy to larger numbers of molecular species concurrently visualized by distinct markers is of great importance for advanced biological applications. To date, up to four markers had been distinguished in STED experiments featuring comparatively elaborate imaging schemes and optical setups, and exploiting various properties of the fluorophores. Here we present a simple yet versatile STED design for multicolour imaging below the diffraction limit. A hyperspectral detection arrangement (hyperSTED) collects the fluorescence in four spectral channels, allowing the separation of four markers with only one excitation wavelength and a single STED beam...
April 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28379846/sted-microscopy-visualizes-energy-deposition-of-single-ions-in-a-solid-state-detector-beyond-diffraction-limit
#12
M Niklas, M Henrich, O Jäkel, J Engelhardt, A Abdollahi, S Greilich
Fluorescent nuclear track detectors (FNTDs) allow for visualization of single-particle traversal in clinical ion beams. The point spread function of the confocal readout has so far hindered a more detailed characterization of the track spots-the ion's characteristic signature left in the FNTD. Here we report on the readout of the FNTD by optical nanoscopy, namely stimulated emission depletion microscopy. It was firstly possible to visualize the track spots of carbon ions and protons beyond the diffraction limit of conventional light microscopy with a resolving power of approximately 80 nm (confocal: 320 nm)...
April 5, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28355484/podosome-force-generation-machinery-a-local-balance-between-protrusion-at-the-core-and-traction-at-the-ring
#13
Anaïs Bouissou, Amsha Proag, Nicolas Bourg, Karine Pingris, Clément Cabriel, Stéphanie Balor, Thomas Mangeat, Christophe Thibault, Christophe Vieu, Guillaume Dupuis, Emmanuel Fort, Sandrine Lévêque-Fort, Isabelle Maridonneau-Parini, Renaud Poincloux
Determining how cells generate and transduce mechanical forces at the nanoscale is a major technical challenge for the understanding of numerous physiological and pathological processes. Podosomes are submicrometer cell structures with a columnar F-actin core surrounded by a ring of adhesion proteins, which possess the singular ability to protrude into and probe the extracellular matrix. Using protrusion force microscopy, we have previously shown that single podosomes produce local nanoscale protrusions on the extracellular environment...
April 25, 2017: ACS Nano
https://www.readbyqxmd.com/read/28317930/achromatic-light-patterning-and-improved-image-reconstruction-for-parallelized-resolft-nanoscopy
#14
Andriy Chmyrov, Marcel Leutenegger, Tim Grotjohann, Andreas Schönle, Jan Keller-Findeisen, Lars Kastrup, Stefan Jakobs, Gerald Donnert, Steffen J Sahl, Stefan W Hell
Fluorescence microscopy is rapidly turning into nanoscopy. Among the various nanoscopy methods, the STED/RESOLFT super-resolution family has recently been expanded to image even large fields of view within a few seconds. This advance relies on using light patterns featuring substantial arrays of intensity minima for discerning features by switching their fluorophores between 'on' and 'off' states of fluorescence. Here we show that splitting the light with a grating and recombining it in the focal plane of the objective lens renders arrays of minima with wavelength-independent periodicity...
March 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28287222/mapping-of-bernal-and-non-bernal-stacking-domains-in-bilayer-graphene-using-infrared-nanoscopy
#15
Gyouil Jeong, Boogeon Choi, Deok-Soo Kim, Seongjin Ahn, Baekwon Park, Jin Hyoun Kang, Hongki Min, Byung Hee Hong, Zee Hwan Kim
Bilayer graphene (BLG) shows great potential as a new material for opto-electronic devices because its bandgap can be controlled by varying the stacking orders, as well as by applying an external electric field. An imaging technique that can visualize and characterize various stacking domains in BLG may greatly help in fully utilizing such properties of BLG. Here we demonstrate that infrared (IR) scattering-type scanning near-field optical microscopy (sSNOM) can visualize Bernal and non-Bernal stacking domains of BLG, based on the stacking-specific inter- and intra-band optical conductivities...
March 13, 2017: Nanoscale
https://www.readbyqxmd.com/read/28262023/ground-state-depletion-nanoscopy-resolves-semiconductor-nanowire-barcode-segments-at-room-temperature
#16
Joanna Oracz, Karl Adolfsson, Volker Westphal, Czesław Radzewicz, Magnus T Borgström, Steffen J Sahl, Christelle N Prinz, Stefan W Hell
Nanowires hold great promise as tools for probing and interacting with various molecular and biological systems. Their unique geometrical properties (typically <100 nm in diameter and a few micrometers in length) enable minimally invasive interactions with living cells, so that electrical signals or forces can be monitored. All such experiments require in situ high-resolution imaging to provide context. While there is a clear need to extend visualization capabilities to the nanoscale, no suitable super-resolution far-field photoluminescence microscopy of extended semiconductor emitters has been described...
April 12, 2017: Nano Letters
https://www.readbyqxmd.com/read/28262022/stimulated-emission-depletion-microscopy
#17
Hans Blom, Jerker Widengren
Despite its short history, diffraction-unlimited fluorescence microscopy techniques have already made a substantial imprint in the biological sciences. In this review, we describe how stimulated emission depletion (STED) imaging originally evolved, how it compares to other optical super-resolution imaging techniques, and what advantages it provides compared to previous golden-standards for biological microscopy, such as diffraction-limited optical microscopy and electron microscopy. We outline the prerequisites for successful STED imaging experiments, emphasizing the equally critical roles of instrumentation, sample preparation, and photophysics, and describe major evolving strategies for how to push the borders of STED imaging even further in life science...
March 6, 2017: Chemical Reviews
https://www.readbyqxmd.com/read/28257567/hybrid-nanoscopy-of-hybrid-nanomaterials
#18
Patricia Bondia, Rocío Jurado, Santiago Casado, José M Domínguez-Vera, Natividad Gálvez, Cristina Flors
The combination of complementary techniques to characterize materials at the nanoscale is crucial to gain a more complete picture of their structure, a key step to design and fabricate new materials with improved properties and diverse functions. Here it is shown that correlative atomic force microscopy (AFM) and localization-based super-resolution microscopy is a useful tool that provides insight into the structure and emissive properties of fluorescent β-lactoglobulin (βLG) amyloid-like fibrils. These hybrid materials are made by functionalization of βLG with organic fluorophores and quantum dots, the latter being relevant for the production of 1D inorganic nanostructures templated by self-assembling peptides...
May 2017: Small
https://www.readbyqxmd.com/read/28256876/fluorescent-nanowire-ring-illumination-for-wide-field-far-field-subdiffraction-imaging
#19
Xiaowei Liu, Cuifang Kuang, Xiang Hao, Chenlei Pang, Pengfei Xu, Haifeng Li, Ying Liu, Chao Yu, Yingke Xu, Di Nan, Weidong Shen, Yue Fang, Lenian He, Xu Liu, Qing Yang
Here we demonstrate an active method which pioneers in utilizing a combination of a spatial frequency shift and a Stokes frequency shift to enable wide-field far-field subdiffraction imaging. A fluorescent nanowire ring acts as a localized source and is combined with a film waveguide to produce omnidirectional illuminating evanescent waves. Benefitting from the high wave vector of illumination, the high spatial frequencies of an object can be shifted to the passband of a conventional imaging system, contributing subwavelength spatial information to the far-field image...
February 17, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28225761/amplified-stimulated-emission-in-upconversion-nanoparticles-for-super-resolution-nanoscopy
#20
Yujia Liu, Yiqing Lu, Xusan Yang, Xianlin Zheng, Shihui Wen, Fan Wang, Xavier Vidal, Jiangbo Zhao, Deming Liu, Zhiguang Zhou, Chenshuo Ma, Jiajia Zhou, James A Piper, Peng Xi, Dayong Jin
Lanthanide-doped glasses and crystals are attractive for laser applications because the metastable energy levels of the trivalent lanthanide ions facilitate the establishment of population inversion and amplified stimulated emission at relatively low pump power. At the nanometre scale, lanthanide-doped upconversion nanoparticles (UCNPs) can now be made with precisely controlled phase, dimension and doping level. When excited in the near-infrared, these UCNPs emit stable, bright visible luminescence at a variety of selectable wavelengths, with single-nanoparticle sensitivity, which makes them suitable for advanced luminescence microscopy applications...
March 9, 2017: Nature
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