scholarly journals An optogenetic method for interrogating YAP1 and TAZ nuclear-cytoplasmic shuttling

2021 ◽  
Author(s):  
Anna M. Dowbaj ◽  
Robert P. Jenkins ◽  
Daniel Williamson ◽  
John M. Heddleston ◽  
Alessandro Ciccarelli ◽  
...  
Keyword(s):  
Nuclear Export ◽  
Transcriptional Regulators ◽  
Light Sheet ◽  
Light Illumination ◽  
Biological Processes ◽  
Entry And Exit ◽  
Nuclear Entry ◽  
Light Sheet Microscopy ◽  
Import And Export ◽  
Intercellular Variability

The shuttling of transcription factors and transcriptional regulators into and out of the nucleus is central to the regulation of many biological processes. Here we describe a new method for studying the rates of nuclear entry and exit of transcriptional regulators. A photo-responsive AsLOV (Avena sativa Light Oxygen Voltage) domain is used to sequester fluorescently-labelled transcriptional regulators YAP1 and TAZ/WWTR1 on the surface of mitochondria and reversibly release them upon blue light illumination. After dissociation, fluorescent signals from mitochondria, cytoplasm and nucleus are extracted with a bespoke app and used to generate rates of nuclear entry and exit. Using this method, we demonstrate that phosphorylation of YAP1 on canonical sites enhances its rate of nuclear export. Moreover, we provide evidence that, despite high intercellular variability, YAP1 import and export rates correlated within the same cell. By simultaneously releasing YAP1 and TAZ from sequestration, we show that their rates of entry and exit are correlated. Furthermore, combining the optogenetic release of YAP1 with lattice light-sheet microscopy revealed high heterogeneity of YAP1 dynamics within different cytoplasmic regions, demonstrating the utility and versatility of our tool to study protein dynamics.

scholarly journals An optogenetic method for interrogating YAP1 and TAZ nuclear-cytoplasmic shuttling

2020 ◽  
Author(s):  
Anna M. Dowbaj ◽  
Robert P. Jenkins ◽  
John M. Heddleston ◽  
Alessandro Ciccarelli ◽  
Todd Fallesen ◽  
...  
Keyword(s):  
Nuclear Export ◽  
Transcriptional Regulators ◽  
Light Illumination ◽  
Biological Processes ◽  
Entry And Exit ◽  
Nuclear Entry ◽  
3D Data ◽  
Import And Export ◽  
Shed Light ◽  
Intercellular Variability

AbstractThe shuttling of transcription factors and transcriptional regulators in and out of the nucleus is central to the regulation of many biological processes. Here we describe a new method for studying the rates of nuclear entry and exit of transcriptional regulators. A photo-responsive AsLOV (Avena sativa Light Oxygen Voltage) domain is used to sequester fluorescently-labelled transcriptional regulators YAP1 and TAZ/WWTR1 on the surface of mitochondria and reversibly release them upon blue light illumination. After dissociation, fluorescent signals from mitochondria, cytoplasm and nucleus are extracted with a bespoke app and used to generate rates of nuclear entry and exit. Using this method, we demonstrate that phosphorylation of YAP1 on canonical sites enhances its rate of nuclear export. Moreover, we provide evidences that, despite high intercellular variability, YAP1 import and export rates correlated within the same cell. By simultaneously releasing YAP1 and TAZ from sequestration, we show that their rates of entry and exit are correlated. Furthermore, tracking of light-sensitive YAP1 with lattice lightsheet microscopy revealed high heterogeneity of YAP1 dynamics within different subcellular regions, suggesting that implementing high resolution volumetric 3D data could shed light on new mechanisms of nuclear-cytoplasmic shuttling of proteins.

scholarly journals Single-molecule light-sheet microscopy with local nanopipette delivery

2020 ◽  
Author(s):  
B. Li ◽  
A. Ponjavic ◽  
W. H. Chen ◽  
L. Hopkins ◽  
C. Hughes ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Single Molecule ◽  
Single Molecules ◽  
Light Sheet ◽  
Local Delivery ◽  
Live Cells ◽  
Biological Processes ◽  
Light Sheet Microscopy ◽  
Wide Range

AbstractDetection of single molecules in biological systems has rapidly increased in resolution over the past decade. However, delivery of single molecules has remained a challenge. Currently there is no effective method that can both introduce a precise amount of molecules onto or into a single cell at a defined position, and then image the cellular response. Here we have combined light sheet microscopy with local delivery, using a nanopipette, to accurately deliver individual proteins to a defined position. We call this method local delivery selective plane illumination microscopy (ldSPIM). ldSPIM uses a nanopipette and the ionic feedback current at the nanopipette tip to control the position from which molecules are delivered. The number of proteins delivered can be controlled by varying the voltage applied. For single-molecule detection, we implemented single-objective SPIM using a reflective atomic force microscopy cantilever to create a 2µm thin sheet. Using this setup, we demonstrate that ldSPIM can deliver single fluorescently-labeled proteins onto the plasma membrane of HK293 cells or into the cytoplasm. Next, we deposited aggregates of amyloid-β, which causes proteotoxicity relevant to Alzheimer’s disease, onto a single macrophage stably expressing a MyDD88-eGFP fusion construct. Whole-cell imaging in 3D mode enables live detection of MyDD88 accumulation and formation of MyDDosome signaling complexes, as a result of aggregate-induced triggering of toll-like receptor 4. Overall, we demonstrate a novel multifunctional imaging system capable of precise delivery of single proteins to a specific location on the cell surface or inside the cytoplasm and high-speed 3D detection at single-molecule resolution within live cells.Statement of SignificanceThis paper describes and validates a new method to study biological processes based on the controlled local delivery of molecules onto or into the cell, combined with single molecule imaging using light sheet microscopy. we not only demonstrate the instrument’s capability of delivering controlled numbers of molecules to a defined position, down to the level of single molecules, but also its potential in study of the triggering of the innate immune response by protein aggregates, a key process in the development of neurodegenerative diseases such as Alzheimer’s disease. The same approach could be applied to a wide range of other important biological processes allowing them to be followed in live cells in real-time, hence it will be of great interest to the biophysical community.

scholarly journals Coupling optogenetics and light-sheet microscopy, a method to study signal transduction in vivo

2017 ◽  
Author(s):  
Prameet Kaur ◽  
Timothy E. Saunders ◽  
Nicholas S. Tolwinski
Keyword(s):  
Wnt Signaling ◽  
Signaling Pathways ◽  
Fluorescent Protein ◽  
Light Sheet ◽  
Light Illumination ◽  
Temporal Regulation ◽  
Light Sheet Microscopy ◽  
Cryptochrome 2

AbstractOptogenetics allows precise, fast and reversible intervention in biological processes. Light-sheet microscopy allows observation of the full course of embryonic development from egg to larva. Bringing the two approaches together allows unparalleled precision into the temporal regulation of signaling pathways and cellular processes in vivo. To develop this method, we investigated the regulation of canonical Wnt signaling during anterior-posterior patterning of the Drosophila embryonic epidermis. Cryptochrome 2 (CRY2) from Arabidopsis Thaliana was fused to mCherry fluorescent protein and Drosophila β–catenin to form an easy to visualize optogenetic switch. Blue light illumination caused oligomerization of the fusion protein and inhibited downstream Wnt signaling in vitro and in vivo. Temporal inactivation of β–catenin confirmed that Wnt signaling is required not only for Drosophila pattern formation, but also for maintenance later in development. We anticipate that this method will be easily extendable to other developmental signaling pathways and many other experimental systems.

Light-Sheet Microscopy and Its Potential for Understanding Developmental Processes

2019 ◽  
Vol 35 (1) ◽  
pp. 655-681 ◽  
Author(s):  
Yinan Wan ◽  
Katie McDole ◽  
Philipp J. Keller
Keyword(s):  
Developmental Biology ◽  
Single Molecule ◽  
Light Sheet ◽  
Experimental Investigations ◽  
Biological Processes ◽  
Spatiotemporal Resolution ◽  
Developmental Processes ◽  
Light Sheet Microscopy ◽  
Good Spatial Resolution

The ability to visualize and quantitatively measure dynamic biological processes in vivo and at high spatiotemporal resolution is of fundamental importance to experimental investigations in developmental biology. Light-sheet microscopy is particularly well suited to providing such data, since it offers exceptionally high imaging speed and good spatial resolution while minimizing light-induced damage to the specimen. We review core principles and recent advances in light-sheet microscopy, with a focus on concepts and implementations relevant for applications in developmental biology. We discuss how light-sheet microcopy has helped advance our understanding of developmental processes from single-molecule to whole-organism studies, assess the potential for synergies with other state-of-the-art technologies, and introduce methods for computational image and data analysis. Finally, we explore the future trajectory of light-sheet microscopy, discuss key efforts to disseminate new light-sheet technology, and identify exciting opportunities for further advances.

scholarly journals Achromatic terahertz Airy beam generation with dielectric metasurfaces

Nanophotonics ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Qingqing Cheng ◽  
Juncheng Wang ◽  
Ling Ma ◽  
Zhixiong Shen ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Biomedical Imaging ◽  
Frequency Dispersion ◽  
Light Sheet ◽  
Photonic Devices ◽  
Self Healing ◽  
Beam Focusing ◽  
Light Sheet Microscopy ◽  
Airy Beam ◽  
Potential Applications ◽  
Airy Beams

AbstractAiry beams exhibit intriguing properties such as nonspreading, self-bending, and self-healing and have attracted considerable recent interest because of their many potential applications in photonics, such as to beam focusing, light-sheet microscopy, and biomedical imaging. However, previous approaches to generate Airy beams using photonic structures have suffered from severe chromatic problems arising from strong frequency dispersion of the scatterers. Here, we design and fabricate a metasurface composed of silicon posts for the frequency range 0.4–0.8 THz in transmission mode, and we experimentally demonstrate achromatic Airy beams exhibiting autofocusing properties. We further show numerically that a generated achromatic Airy-beam-based metalens exhibits self-healing properties that are immune to scattering by particles and that it also possesses a larger depth of focus than a traditional metalens. Our results pave the way to the realization of flat photonic devices for applications to noninvasive biomedical imaging and light-sheet microscopy, and we provide a numerical demonstration of a device protocol.

scholarly journals Single-Molecule Light-Sheet Microscopy with Local Nanopipette Delivery

2021 ◽  
Vol 93 (8) ◽  
pp. 4092-4099
Author(s):  
Bing Li ◽  
Aleks Ponjavic ◽  
Wei-Hsin Chen ◽  
Lee Hopkins ◽  
Craig Hughes ◽  
...  
Keyword(s):  
Single Molecule ◽  
Light Sheet ◽  
Light Sheet Microscopy

scholarly journals Effect of captopril on post-infarction remodelling visualized by light sheet microscopy and echocardiography

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Urmas Roostalu ◽  
Louise Thisted ◽  
Jacob Lercke Skytte ◽  
Casper Gravesen Salinas ◽  
Philip Juhl Pedersen ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Light Sheet ◽  
Automated Image Analysis ◽  
Border Zone ◽  
Vascular Density ◽  
Mouse Heart ◽  
Imaging Method ◽  
Light Sheet Microscopy ◽  
Post Surgery ◽  
Captopril Treatment

AbstractAngiotensin converting enzyme inhibitors, among them captopril, improve survival following myocardial infarction (MI). The mechanisms of captopril action remain inadequately understood due to its diverse effects on multiple signalling pathways at different time periods following MI. Here we aimed to establish the role of captopril in late-stage post-MI remodelling. Left anterior descending artery (LAD) ligation or sham surgery was carried out in male C57BL/6J mice. Seven days post-surgery LAD ligated mice were allocated to daily vehicle or captopril treatment continued over four weeks. To provide comprehensive characterization of the changes in mouse heart following MI a 3D light sheet imaging method was established together with automated image analysis workflow. The combination of echocardiography and light sheet imaging enabled to assess cardiac function and the underlying morphological changes. We show that delayed captopril treatment does not affect infarct size but prevents left ventricle dilation and hypertrophy, resulting in improved ejection fraction. Quantification of lectin perfused blood vessels showed improved vascular density in the infarct border zone in captopril treated mice in comparison to vehicle dosed control mice. These results validate the applicability of combined echocardiographic and light sheet assessment of drug mode of action in preclinical cardiovascular research.

The Light-Sheet Microscopy

2021 ◽  
Author(s):  
Rolf Theodor Borlinghaus
Keyword(s):  
Light Sheet ◽  
Light Sheet Microscopy
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