1
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Liu M, Jin S, Agabiti SS, Jensen TB, Yang T, Radda JSD, Ruiz CF, Baldissera G, Rajaei M, Townsend JP, Muzumdar MD, Wang S. Tracing the evolution of single-cell cancer 3D genomes: an atlas for cancer gene discovery. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.07.23.550157. [PMID: 37546882 PMCID: PMC10401964 DOI: 10.1101/2023.07.23.550157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Although three-dimensional (3D) genome structures are altered in cancer cells, little is known about how these changes evolve and diversify during cancer progression. Leveraging genome-wide chromatin tracing to visualize 3D genome folding directly in tissues, we generated 3D genome cancer atlases of murine lung and pancreatic adenocarcinoma. Our data reveal stereotypical, non-monotonic, and stage-specific alterations in 3D genome folding heterogeneity, compaction, and compartmentalization as cancers progress from normal to preinvasive and ultimately to invasive tumors, discovering a potential structural bottleneck in early tumor progression. Remarkably, 3D genome architectures distinguish histologic cancer states in single cells, despite considerable cell-to-cell heterogeneity. Gene-level analyses of evolutionary changes in 3D genome compartmentalization not only showed compartment-associated genes are more homogeneously regulated, but also elucidated prognostic and dependency genes in lung adenocarcinoma and a previously unappreciated role for polycomb-group protein Rnf2 in 3D genome regulation. Our results demonstrate the utility of mapping the single-cell cancer 3D genome in tissues and illuminate its potential to identify new diagnostic, prognostic, and therapeutic biomarkers in cancer.
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2
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Engl W, Kunstar-Thomas A, Chen S, Ng WS, Sielaff H, Zhao ZW. Single-molecule imaging of SWI/SNF chromatin remodelers reveals bromodomain-mediated and cancer-mutants-specific landscape of multi-modal DNA-binding dynamics. Nat Commun 2024; 15:7646. [PMID: 39223123 PMCID: PMC11369179 DOI: 10.1038/s41467-024-52040-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Accepted: 08/22/2024] [Indexed: 09/04/2024] Open
Abstract
Despite their prevalent cancer implications, the in vivo dynamics of SWI/SNF chromatin remodelers and how misregulation of such dynamics underpins cancer remain poorly understood. Using live-cell single-molecule tracking, we quantify the intranuclear diffusion and chromatin-binding of three key subunits common to all major human SWI/SNF remodeler complexes (BAF57, BAF155 and BRG1), and resolve two temporally distinct stable binding modes for the fully assembled complex. Super-resolved density mapping reveals heterogeneous, nanoscale remodeler binding "hotspots" across the nucleoplasm where multiple binding events (especially longer-lived ones) preferentially cluster. Importantly, we uncover distinct roles of the bromodomain in modulating chromatin binding/targeting in a DNA-accessibility-dependent manner, pointing to a model where successive longer-lived binding within "hotspots" leads to sustained productive remodeling. Finally, systematic comparison of six common BRG1 mutants implicated in various cancers unveils alterations in chromatin-binding dynamics unique to each mutant, shedding insight into a multi-modal landscape regulating the spatio-temporal organizational dynamics of SWI/SNF remodelers.
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Affiliation(s)
- Wilfried Engl
- Department of Chemistry, Faculty of Science, National University of Singapore, Singapore, 119543, Singapore
- Centre for BioImaging Sciences, Faculty of Science, National University of Singapore, Singapore, 117557, Singapore
| | - Aliz Kunstar-Thomas
- Department of Chemistry, Faculty of Science, National University of Singapore, Singapore, 119543, Singapore
- Centre for BioImaging Sciences, Faculty of Science, National University of Singapore, Singapore, 117557, Singapore
| | - Siyi Chen
- Department of Chemistry, Faculty of Science, National University of Singapore, Singapore, 119543, Singapore
- Centre for BioImaging Sciences, Faculty of Science, National University of Singapore, Singapore, 117557, Singapore
| | - Woei Shyuan Ng
- Department of Chemistry, Faculty of Science, National University of Singapore, Singapore, 119543, Singapore
- Centre for BioImaging Sciences, Faculty of Science, National University of Singapore, Singapore, 117557, Singapore
| | - Hendrik Sielaff
- Department of Chemistry, Faculty of Science, National University of Singapore, Singapore, 119543, Singapore
- Centre for BioImaging Sciences, Faculty of Science, National University of Singapore, Singapore, 117557, Singapore
| | - Ziqing Winston Zhao
- Department of Chemistry, Faculty of Science, National University of Singapore, Singapore, 119543, Singapore.
- Centre for BioImaging Sciences, Faculty of Science, National University of Singapore, Singapore, 117557, Singapore.
- Mechanobiology Institute, National University of Singapore, Singapore, 117411, Singapore.
- Integrative Sciences and Engineering Programme, National University of Singapore, Singapore, 119077, Singapore.
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3
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Chen J. Structured Stochastic Curve Fitting without Gradient Calculation. JOURNAL OF COMPUTATIONAL MATHEMATICS AND DATA SCIENCE 2024; 12:100097. [PMID: 39323491 PMCID: PMC11423772 DOI: 10.1016/j.jcmds.2024.100097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/27/2024]
Abstract
Optimization of parameters and hyperparameters is a general process for any data analysis. Because not all models are mathematically well-behaved, stochastic optimization can be useful in many analyses by randomly choosing parameters in each optimization iteration. Many such algorithms have been reported and applied in chemistry data analysis, but the one reported here is interesting to check out, where a naïve algorithm searches each parameter sequentially and randomly in its bounds. Then it picks the best for the next iteration. Thus, one can ignore irrational solution of the model itself or its gradient in parameter space.
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Affiliation(s)
- Jixin Chen
- Department of Chemistry and Biochemistry, Nanoscale & Quantum Phenomena Institute, Ohio University, Athens, Ohio 45701, United States
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4
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Aliakbarinodehi N, Niederkofler S, Emilsson G, Parkkila P, Olsén E, Jing Y, Sjöberg M, Agnarsson B, Lindfors L, Höök F. Time-Resolved Inspection of Ionizable Lipid-Facilitated Lipid Nanoparticle Disintegration and Cargo Release at an Early Endosomal Membrane Mimic. ACS NANO 2024; 18:22989-23000. [PMID: 39133894 PMCID: PMC11363135 DOI: 10.1021/acsnano.4c04519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Revised: 07/26/2024] [Accepted: 07/30/2024] [Indexed: 08/28/2024]
Abstract
Advances in lipid nanoparticle (LNP) design have contributed notably to the emergence of the current clinically approved mRNA-based vaccines and are of high relevance for delivering mRNA to combat diseases where therapeutic alternatives are sparse. LNP-assisted mRNA delivery utilizes ionizable lipid-mediated cargo translocation across the endosomal membrane driven by the acidification of the endosomal environment. However, this process occurs at a low efficiency, a few percent at the best. Utilizing surface-sensitive fluorescence microscopy with a single LNP and mRNA resolution, we have investigated pH-controlled interactions between individual LNPs and a planar anionic supported lipid bilayer (SLB) formed on nanoporous silica, mimicking the electrostatic conditions of the early endosomal membrane. For LNPs with an average diameter of 140 nm, fusion with the anionic SLB preferentially occurred when the pH was reduced from 6.6 to 6.0. Furthermore, there was a delay in the onset of LNP fusion after the pH drop, and upon fusion, a significant fraction (>70%) of mRNA was released into the acidic solution representing the endosomal lumen, while a fraction of mRNA remained bound to the SLB even after reversing the pH to neutral cytosolic conditions. Finally, a comparison of the fusion efficiency of two LNP formulations with different surface concentrations of gel-forming lipids correlated with differences in the protein translation efficiency previously observed in human primary cell transfection studies. Together, these findings emphasize the relevance of biophysical investigations of ionizable lipid-containing LNP-assisted mRNA delivery mechanisms while potentially also offering means to optimize the design of LNPs with enhanced endosomal escape capabilities.
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Affiliation(s)
- Nima Aliakbarinodehi
- Department
of Physics, Division of Nano and Biophysics, Chalmers University of Technology, Göteborg 41296, Sweden
| | - Simon Niederkofler
- Department
of Physics, Division of Nano and Biophysics, Chalmers University of Technology, Göteborg 41296, Sweden
| | - Gustav Emilsson
- Advanced
Drug Delivery, Pharmaceutical Sciences, AstraZeneca R&D, Mölndal 43181, Sweden
| | - Petteri Parkkila
- Department
of Physics, Division of Nano and Biophysics, Chalmers University of Technology, Göteborg 41296, Sweden
| | - Erik Olsén
- Department
of Physics, Division of Nano and Biophysics, Chalmers University of Technology, Göteborg 41296, Sweden
| | - Yujia Jing
- Advanced
Drug Delivery, Pharmaceutical Sciences, AstraZeneca R&D, Mölndal 43181, Sweden
| | - Mattias Sjöberg
- Department
of Physics, Division of Nano and Biophysics, Chalmers University of Technology, Göteborg 41296, Sweden
| | - Björn Agnarsson
- Department
of Physics, Division of Nano and Biophysics, Chalmers University of Technology, Göteborg 41296, Sweden
| | - Lennart Lindfors
- Advanced
Drug Delivery, Pharmaceutical Sciences, AstraZeneca R&D, Mölndal 43181, Sweden
| | - Fredrik Höök
- Department
of Physics, Division of Nano and Biophysics, Chalmers University of Technology, Göteborg 41296, Sweden
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5
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Go GH, Lee DG, Oh J, Song G, Lee D, Jang M. Meta Shack-Hartmann wavefront sensor with large sampling density and large angular field of view: phase imaging of complex objects. LIGHT, SCIENCE & APPLICATIONS 2024; 13:187. [PMID: 39134518 PMCID: PMC11319597 DOI: 10.1038/s41377-024-01528-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 07/05/2024] [Accepted: 07/11/2024] [Indexed: 08/15/2024]
Abstract
Shack-Hartmann wavefront sensors measure the local slopes of an incoming wavefront based on the displacement of focal spots created by a lenslet array, serving as key components for adaptive optics for astronomical and biomedical imaging. Traditionally, the challenges in increasing the density and the curvature of the lenslet have limited the use of such wavefront sensors in characterizing slowly varying wavefront structures. Here, we develop a metasurface-enhanced Shack-Hartmann wavefront sensor (meta SHWFS) to break this limit, considering the interplay between the lenslet parameters and the performance of SHWFS. We experimentally validate the meta SHWFS with a sampling density of 5963 per mm2 and a maximum acceptance angle of 8° which outperforms the traditional SFWFS by an order of magnitude. Furthermore, to the best of our knowledge, we demonstrate the first use of a wavefront sensing scheme in single-shot phase imaging of highly complex patterns, including biological tissue patterns. The proposed approach opens up new opportunities in incorporating exceptional light manipulation capabilities of the metasurface platform in complex wavefront characterization.
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Affiliation(s)
- Gi-Hyun Go
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Dong-Gu Lee
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Jaeyeon Oh
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Gookho Song
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Doeon Lee
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Mooseok Jang
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.
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6
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Jiao M, Danthi P, Yu Y. Cholesterol-Dependent Membrane Deformation by Metastable Viral Capsids Facilitates Entry. ACS Infect Dis 2024; 10:2728-2740. [PMID: 38873897 DOI: 10.1021/acsinfecdis.4c00085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2024]
Abstract
Nonenveloped viruses employ unique entry mechanisms to breach and infect host cells. Understanding these mechanisms is crucial for developing antiviral strategies. Prevailing perspective suggests that nonenveloped viruses release membrane pore-forming peptides to breach host membranes. However, the precise involvement of the viral capsid in this entry remains elusive. Our study presents direct observations elucidating the dynamically distinctive steps through which metastable reovirus capsids disrupt host lipid membranes as they uncoat into partially hydrophobic intermediate particles. Using both live cells and model membrane systems, our key finding is that reovirus capsids actively deform and permeabilize lipid membranes in a cholesterol-dependent process. Unlike membrane pore-forming peptides, these metastable viral capsids induce more extensive membrane perturbations, including budding, bridging between adjacent membranes, and complete rupture. Notably, cholesterol enhances subviral particle adsorption, resulting in the formation of pores equivalent to the capsid size. This cholesterol dependence is attributed to the lipid condensing effect, particularly prominent at an intermediate cholesterol level. Furthermore, our results reveal a positive correlation between membrane disruption extent and efficiency of viral variants in establishing infection. This study unveils the crucial role of capsid-lipid interaction in nonenveloped virus entry, providing new insights into how cholesterol homeostasis influences virus infection dynamics.
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Affiliation(s)
- Mengchi Jiao
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405-7102, United States
| | - Pranav Danthi
- Department of Biology, Indiana University, Bloomington, Indiana 47405-7102, United States
| | - Yan Yu
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405-7102, United States
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7
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Dunn CM, Foust D, Gao Y, Biteen JS, Shaw SL, Kearns DB. Nascent flagellar basal bodies are immobilized by rod assembly in Bacillus subtilis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.02.606393. [PMID: 39211283 PMCID: PMC11360914 DOI: 10.1101/2024.08.02.606393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
Flagella are complex, trans-envelope nanomachines that localize to species- specific cellular addresses. Here we study the localization dynamics of the earliest stage of basal body formation in Bacillus subtilis using a fluorescent fusion to the C-ring protein FliM. We find that B. subtilis basal bodies do not exhibit dynamic subunit exchange and are largely stationary at steady state, consistent with flagellar assembly through the peptidoglycan. Rare basal bodies were observed to be mobile however, and the frequency of basal body mobility is elevated both early in basal body assembly and when the rod is mutated. Thus, basal body mobility is a precursor to patterning and we propose that rod polymerization probes the peptidoglycan superstructure for pores of sufficient diameter that permit rod completion. Furthermore, mutation of the rod also disrupts basal body patterning in a way that phenocopies mutation of the cytoplasmic flagellar patterning protein FlhF. We infer that conformational changes in the basal body exchange information between rod synthesis and the cytoplasmic patterning proteins to restrict assembly at certain pores established by a grid-like pattern pre-existent in the peptidoglycan itself. IMPORTANCE Bacteria insert flagella in a species-specific pattern on the cell body, but how patterns are achieved is poorly understood. In bacteria with a single polar flagellum, a marker protein localizes to the cell pole and nucleates the assembly of the flagellum at that site. Bacillus subtilis assembles ∼15 flagella over the length of the cell body in a grid-like pattern and lacks all proteins associated with targeted assembly in polarly flagellated bacteria. Here we show that B. subtilis basal bodies are mobile soon after assembly and become immobilized when the flagellar rod transits the peptidoglycan wall. Moreover, defects in the flagellar rod lead to an asymmetric distribution of flagella with respect to the midcell. We conclude that the patterning of flagella is different in B. subtilis , and we infer that the B. subtilis rod probes the peptidoglycan for holes that can accommodate the machine.
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8
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Rodríguez Pérez F, Natwick D, Schiff L, McSwiggen D, Heckert A, Huey M, Morrison H, Loo M, Miranda RG, Filbin J, Ortega J, Van Buren K, Murnock D, Tao A, Butler R, Cheng K, Tarvestad W, Zhang Z, Gonzalez E, Miller RM, Kelly M, Tang Y, Ho J, Anderson D, Bashore C, Basham S. WRN inhibition leads to its chromatin-associated degradation via the PIAS4-RNF4-p97/VCP axis. Nat Commun 2024; 15:6059. [PMID: 39025847 PMCID: PMC11258360 DOI: 10.1038/s41467-024-50178-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 07/01/2024] [Indexed: 07/20/2024] Open
Abstract
Synthetic lethality provides an attractive strategy for developing targeted cancer therapies. For example, cancer cells with high levels of microsatellite instability (MSI-H) are dependent on the Werner (WRN) helicase for survival. However, the mechanisms that regulate WRN spatiotemporal dynamics remain poorly understood. Here, we used single-molecule tracking (SMT) in combination with a WRN inhibitor to examine WRN dynamics within the nuclei of living cancer cells. WRN inhibition traps the helicase on chromatin, requiring p97/VCP for extraction and proteasomal degradation in a MSI-H dependent manner. Using a phenotypic screen, we identify the PIAS4-RNF4 axis as the pathway responsible for WRN degradation. Finally, we show that co-inhibition of WRN and SUMOylation has an additive toxic effect in MSI-H cells and confirm the in vivo activity of WRN inhibition using an MSI-H mouse xenograft model. This work elucidates a regulatory mechanism for WRN that may facilitate identification of new therapeutic modalities, and highlights the use of SMT as a tool for drug discovery and mechanism-of-action studies.
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Affiliation(s)
| | | | | | | | | | | | | | - Mandy Loo
- Eikon Therapeutics, Hayward, CA, 94545, USA
| | | | | | | | | | | | - Arnold Tao
- Eikon Therapeutics, Hayward, CA, 94545, USA
| | | | | | | | | | | | | | | | | | - Jaclyn Ho
- Eikon Therapeutics, Hayward, CA, 94545, USA
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9
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Liu J, Li Y, Chen T, Zhang F, Xu F. Machine Learning for Single-Molecule Localization Microscopy: From Data Analysis to Quantification. Anal Chem 2024; 96:11103-11114. [PMID: 38946062 DOI: 10.1021/acs.analchem.3c05857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Single-molecule localization microscopy (SMLM) is a versatile tool for realizing nanoscale imaging with visible light and providing unprecedented opportunities to observe bioprocesses. The integration of machine learning with SMLM enhances data analysis by improving efficiency and accuracy. This tutorial aims to provide a comprehensive overview of the data analysis process and theoretical aspects of SMLM, while also highlighting the typical applications of machine learning in this field. By leveraging advanced analytical techniques, SMLM is becoming a powerful quantitative analysis tool for biological research.
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Affiliation(s)
- Jianli Liu
- School of Medical Technology, Beijing Institute of Technology, Beijing 100081, China
| | - Yumian Li
- Advanced Research Institute of Multidisciplinary Science, Beijing Institute of Technology, Beijing 100081, China
- School of Optics and Photonics, Beijing Institute of Technology, Beijing 100081, China
| | - Tailong Chen
- Advanced Research Institute of Multidisciplinary Science, Beijing Institute of Technology, Beijing 100081, China
- School of Optics and Photonics, Beijing Institute of Technology, Beijing 100081, China
| | - Fa Zhang
- School of Medical Technology, Beijing Institute of Technology, Beijing 100081, China
| | - Fan Xu
- Advanced Research Institute of Multidisciplinary Science, Beijing Institute of Technology, Beijing 100081, China
- School of Optics and Photonics, Beijing Institute of Technology, Beijing 100081, China
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10
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Werneck LR, Jessup C, Brandenberger A, Knowles T, Lewandowski CW, Nolan M, Sible K, Etienne ZB, D'Urso B. Cross-correlation image analysis for real-time single particle tracking. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2024; 95:073708. [PMID: 39012180 DOI: 10.1063/5.0206405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Accepted: 06/25/2024] [Indexed: 07/17/2024]
Abstract
Accurately measuring the translations of objects between images is essential in many fields, including biology, medicine, chemistry, and physics. One important application is tracking one or more particles by measuring their apparent displacements in a series of images. Popular methods, such as the center of mass, often require idealized scenarios to reach the shot noise limit of particle tracking and, therefore, are not generally applicable to multiple image types. More general methods, such as maximum likelihood estimation, reliably approach the shot noise limit, but are too computationally intense for use in real-time applications. These limitations are significant, as real-time, shot-noise-limited particle tracking is of paramount importance for feedback control systems. To fill this gap, we introduce a new cross-correlation-based algorithm that approaches shot-noise-limited displacement detection and a graphics processing unit-based implementation for real-time image analysis of a single particle.
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Affiliation(s)
- L R Werneck
- Department of Physics, University of Idaho, Moscow, Idaho 83843, USA
| | - C Jessup
- Department of Physics, Montana State University, Bozeman, Montana 59717, USA
| | - A Brandenberger
- Department of Physics, Montana State University, Bozeman, Montana 59717, USA
| | - T Knowles
- Department of Mathematics, West Virginia University, Morgantown, West Virginia 26506, USA
| | - C W Lewandowski
- Department of Physics, Montana State University, Bozeman, Montana 59717, USA
- Space Dynamics Laboratory, Albuquerque, New Mexico 87106, USA
| | - M Nolan
- Department of Physics, Montana State University, Bozeman, Montana 59717, USA
| | - K Sible
- Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia 26506, USA
- Center for Gravitational Waves and Cosmology, Chestnut Ridge Research Building, Morgantown, West Virginia 26506, USA
- Department of Computer Science and Engineering, University of Notre Dame, South Bend, Indiana 46556, USA
| | - Z B Etienne
- Department of Physics, University of Idaho, Moscow, Idaho 83843, USA
- Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia 26506, USA
- Center for Gravitational Waves and Cosmology, Chestnut Ridge Research Building, Morgantown, West Virginia 26506, USA
| | - B D'Urso
- Department of Physics, Montana State University, Bozeman, Montana 59717, USA
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11
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Stollmann A, Garcia-Guirado J, Hong JS, Rüedi P, Im H, Lee H, Ortega Arroyo J, Quidant R. Molecular fingerprinting of biological nanoparticles with a label-free optofluidic platform. Nat Commun 2024; 15:4109. [PMID: 38750038 PMCID: PMC11096335 DOI: 10.1038/s41467-024-48132-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 04/22/2024] [Indexed: 05/18/2024] Open
Abstract
Label-free detection of multiple analytes in a high-throughput fashion has been one of the long-sought goals in biosensing applications. Yet, for all-optical approaches, interfacing state-of-the-art label-free techniques with microfluidics tools that can process small volumes of sample with high throughput, and with surface chemistry that grants analyte specificity, poses a critical challenge to date. Here, we introduce an optofluidic platform that brings together state-of-the-art digital holography with PDMS microfluidics by using supported lipid bilayers as a surface chemistry building block to integrate both technologies. Specifically, this platform fingerprints heterogeneous biological nanoparticle populations via a multiplexed label-free immunoaffinity assay with single particle sensitivity. First, we characterise the robustness and performance of the platform, and then apply it to profile four distinct ovarian cell-derived extracellular vesicle populations over a panel of surface protein biomarkers, thus developing a unique biomarker fingerprint for each cell line. We foresee that our approach will find many applications where routine and multiplexed characterisation of biological nanoparticles are required.
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Affiliation(s)
- Alexia Stollmann
- Nanophotonic Systems Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, 8092, Zurich, Switzerland
| | - Jose Garcia-Guirado
- Nanophotonic Systems Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, 8092, Zurich, Switzerland
| | - Jae-Sang Hong
- Center for Systems Biology, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Pascal Rüedi
- Nanophotonic Systems Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, 8092, Zurich, Switzerland
| | - Hyungsoon Im
- Center for Systems Biology, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
| | - Hakho Lee
- Center for Systems Biology, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
| | - Jaime Ortega Arroyo
- Nanophotonic Systems Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, 8092, Zurich, Switzerland.
| | - Romain Quidant
- Nanophotonic Systems Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, 8092, Zurich, Switzerland.
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12
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Woolley L, Burbidge A, Vermant J, Christakopoulos F. A microrheological examination of insulin-secreting β-cells in healthy and diabetic-like conditions. SOFT MATTER 2024; 20:3464-3472. [PMID: 38573072 DOI: 10.1039/d3sm01141k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/05/2024]
Abstract
Pancreatic β-cells regulate glucose homeostasis through glucose-stimulated insulin secretion, which is hindered in type-2 diabetes. Transport of the insulin vesicles is expected to be affected by changes in the viscoelastic and transport properties of the cytoplasm. These are evaluated in situ through particle-tracking measurements using a rat insulinoma β-cell line. The use of inert probes assists in decoupling the material properties of the cytoplasm from the active transport through cellular processes. The effect of glucose-stimulated insulin secretion is examined, and the subsequent remodeling of the cytoskeleton, at constant effects of cell activity, is shown to result in reduced mobility of the tracer particles. Induction of diabetic-like conditions is identified to alter the mean-squared displacement of the passive particles in the cytoplasm and diminish its reaction to glucose stimulation.
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Affiliation(s)
- Lukas Woolley
- Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, 8093 Zurich, Switzerland.
| | - Adam Burbidge
- Nestlé Research, Route de Jorat 57, vers-chez-les Blanc, 1000 Lausanne, Switzerland
| | - Jan Vermant
- Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, 8093 Zurich, Switzerland.
| | - Fotis Christakopoulos
- Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, 8093 Zurich, Switzerland.
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13
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Fu B, Brock EE, Andrews R, Breiter JC, Tian R, Toomey CE, Lachica J, Lashley T, Ryten M, Wood NW, Vendruscolo M, Gandhi S, Weiss LE, Beckwith JS, Lee SF. RASP: Optimal Single Puncta Detection in Complex Cellular Backgrounds. J Phys Chem B 2024; 128:3585-3597. [PMID: 38593280 PMCID: PMC11033865 DOI: 10.1021/acs.jpcb.4c00174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 03/01/2024] [Accepted: 03/25/2024] [Indexed: 04/11/2024]
Abstract
Super-resolution and single-molecule microscopies have been increasingly applied to complex biological systems. A major challenge of these approaches is that fluorescent puncta must be detected in the low signal, high noise, heterogeneous background environments of cells and tissue. We present RASP, Radiality Analysis of Single Puncta, a bioimaging-segmentation method that solves this problem. RASP removes false-positive puncta that other analysis methods detect and detects features over a broad range of spatial scales: from single proteins to complex cell phenotypes. RASP outperforms the state-of-the-art methods in precision and speed using image gradients to separate Gaussian-shaped objects from the background. We demonstrate RASP's power by showing that it can extract spatial correlations between microglia, neurons, and α-synuclein oligomers in the human brain. This sensitive, computationally efficient approach enables fluorescent puncta and cellular features to be distinguished in cellular and tissue environments, with sensitivity down to the level of the single protein. Python and MATLAB codes, enabling users to perform this RASP analysis on their own data, are provided as Supporting Information and links to third-party repositories.
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Affiliation(s)
- Bin Fu
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Lensfield
Road, Cambridge CB2 1EW, U.K.
- Aligning
Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, Maryland 20815, United States
| | - Emma E. Brock
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Lensfield
Road, Cambridge CB2 1EW, U.K.
- Aligning
Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, Maryland 20815, United States
| | - Rebecca Andrews
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Lensfield
Road, Cambridge CB2 1EW, U.K.
- Aligning
Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, Maryland 20815, United States
| | - Jonathan C. Breiter
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Lensfield
Road, Cambridge CB2 1EW, U.K.
- Aligning
Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, Maryland 20815, United States
- Centre
for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, U.K.
| | - Ru Tian
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Lensfield
Road, Cambridge CB2 1EW, U.K.
- Aligning
Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, Maryland 20815, United States
- Centre
for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, U.K.
| | - Christina E. Toomey
- Aligning
Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, Maryland 20815, United States
- The
Queen Square Brain Bank for Neurological Disorders, Department of
Clinical and Movement Neuroscience, UCL
Queen Square Institute of Neurology, London WC1N 3BG, U.K.
- Department
of Neurodegenerative Diseases, UCL Queen
Square Institute of Neurology, London WC1N 3BG, U.K.
| | - Joanne Lachica
- Aligning
Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, Maryland 20815, United States
- The
Queen Square Brain Bank for Neurological Disorders, Department of
Clinical and Movement Neuroscience, UCL
Queen Square Institute of Neurology, London WC1N 3BG, U.K.
- The
Francis Crick Institute, King’s Cross, London NW1 1AT, U.K.
| | - Tammaryn Lashley
- Aligning
Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, Maryland 20815, United States
- The
Queen Square Brain Bank for Neurological Disorders, Department of
Clinical and Movement Neuroscience, UCL
Queen Square Institute of Neurology, London WC1N 3BG, U.K.
- Department
of Neurodegenerative Diseases, UCL Queen
Square Institute of Neurology, London WC1N 3BG, U.K.
| | - Mina Ryten
- Aligning
Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, Maryland 20815, United States
- Great
Ormond Street Institute of Child Health, University College London, London WC1E 6BT, U.K.
- UK
Dementia Research Institute at the University of Cambridge, Cambridge CB2 0AH, U.K.
- Department
of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge CB2 0SP, U.K.
| | - Nicholas W. Wood
- Aligning
Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, Maryland 20815, United States
- Department
of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London WC1N 3BG, U.K.
| | - Michele Vendruscolo
- Aligning
Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, Maryland 20815, United States
- Centre
for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, U.K.
| | - Sonia Gandhi
- Aligning
Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, Maryland 20815, United States
- Department
of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London WC1N 3BG, U.K.
- The
Francis Crick Institute, King’s Cross, London NW1 1AT, U.K.
| | - Lucien E. Weiss
- Department of Engineering Physics, Polytechnique
Montréal, Montréal, Québec H3T 1J4, Canada
| | - Joseph S. Beckwith
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Lensfield
Road, Cambridge CB2 1EW, U.K.
- Aligning
Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, Maryland 20815, United States
| | - Steven F. Lee
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Lensfield
Road, Cambridge CB2 1EW, U.K.
- Aligning
Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, Maryland 20815, United States
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14
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Luo X, Zhang J, Tan H, Jiang J, Li J, Wen W. Real-Time 3D Tracking of Multi-Particle in the Wide-Field Illumination Based on Deep Learning. SENSORS (BASEL, SWITZERLAND) 2024; 24:2583. [PMID: 38676200 PMCID: PMC11054292 DOI: 10.3390/s24082583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 04/09/2024] [Accepted: 04/16/2024] [Indexed: 04/28/2024]
Abstract
In diverse realms of research, such as holographic optical tweezer mechanical measurements, colloidal particle motion state examinations, cell tracking, and drug delivery, the localization and analysis of particle motion command paramount significance. Algorithms ranging from conventional numerical methods to advanced deep-learning networks mark substantial strides in the sphere of particle orientation analysis. However, the need for datasets has hindered the application of deep learning in particle tracking. In this work, we elucidated an efficacious methodology pivoted toward generating synthetic datasets conducive to this domain that resonates with robustness and precision when applied to real-world data of tracking 3D particles. We developed a 3D real-time particle positioning network based on the CenterNet network. After conducting experiments, our network has achieved a horizontal positioning error of 0.0478 μm and a z-axis positioning error of 0.1990 μm. It shows the capability to handle real-time tracking of particles, diverse in dimensions, near the focal plane with high precision. In addition, we have rendered all datasets cultivated during this investigation accessible.
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Affiliation(s)
- Xiao Luo
- Department of Physics, The Hong Kong University of Science and Technology, Hong Kong 999077, China;
| | - Jie Zhang
- Advanced Materials Thrust, The Hong Kong University of Science and Technology, Guangzhou 511400, China; (J.Z.); (J.J.); (J.L.)
| | - Handong Tan
- Department of Individualized Interdisciplinary Program (Advanced Materials), The Hong Kong University of Science and Technology, Hong Kong 999077, China;
| | - Jiahao Jiang
- Advanced Materials Thrust, The Hong Kong University of Science and Technology, Guangzhou 511400, China; (J.Z.); (J.J.); (J.L.)
| | - Junda Li
- Advanced Materials Thrust, The Hong Kong University of Science and Technology, Guangzhou 511400, China; (J.Z.); (J.J.); (J.L.)
| | - Weijia Wen
- Department of Physics, The Hong Kong University of Science and Technology, Hong Kong 999077, China;
- Advanced Materials Thrust, The Hong Kong University of Science and Technology, Guangzhou 511400, China; (J.Z.); (J.J.); (J.L.)
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15
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Wang S, Walker-Gibbons R, Watkins B, Flynn M, Krishnan M. A charge-dependent long-ranged force drives tailored assembly of matter in solution. NATURE NANOTECHNOLOGY 2024; 19:485-493. [PMID: 38429493 PMCID: PMC11026162 DOI: 10.1038/s41565-024-01621-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 01/25/2024] [Indexed: 03/03/2024]
Abstract
The interaction between charged objects in solution is generally expected to recapitulate two central principles of electromagnetics: (1) like-charged objects repel, and (2) they do so regardless of the sign of their electrical charge. Here we demonstrate experimentally that the solvent plays a hitherto unforeseen but crucial role in interparticle interactions, and importantly, that interactions in the fluid phase can break charge-reversal symmetry. We show that in aqueous solution, negatively charged particles can attract at long range while positively charged particles repel. In solvents that exhibit an inversion of the net molecular dipole at an interface, such as alcohols, we find that the converse can be true: positively charged particles may attract whereas negatives repel. The observations hold across a wide variety of surface chemistries: from inorganic silica and polymeric particles to polyelectrolyte- and polypeptide-coated surfaces in aqueous solution. A theory of interparticle interactions that invokes solvent structuring at an interface captures the observations. Our study establishes a nanoscopic interfacial mechanism by which solvent molecules may give rise to a strong and long-ranged force in solution, with immediate ramifications for a range of particulate and molecular processes across length scales such as self-assembly, gelation and crystallization, biomolecular condensation, coacervation, and phase segregation.
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Affiliation(s)
- Sida Wang
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - Rowan Walker-Gibbons
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - Bethany Watkins
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - Melissa Flynn
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - Madhavi Krishnan
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, UK.
- The Kavli Institute for Nanoscience Discovery, Oxford, UK.
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16
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Byrne SA, Nyström M, Maquiling V, Kasneci E, Niehorster DC. Precise localization of corneal reflections in eye images using deep learning trained on synthetic data. Behav Res Methods 2024; 56:3226-3241. [PMID: 38114880 PMCID: PMC11133043 DOI: 10.3758/s13428-023-02297-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/15/2023] [Indexed: 12/21/2023]
Abstract
We present a deep learning method for accurately localizing the center of a single corneal reflection (CR) in an eye image. Unlike previous approaches, we use a convolutional neural network (CNN) that was trained solely using synthetic data. Using only synthetic data has the benefit of completely sidestepping the time-consuming process of manual annotation that is required for supervised training on real eye images. To systematically evaluate the accuracy of our method, we first tested it on images with synthetic CRs placed on different backgrounds and embedded in varying levels of noise. Second, we tested the method on two datasets consisting of high-quality videos captured from real eyes. Our method outperformed state-of-the-art algorithmic methods on real eye images with a 3-41.5% reduction in terms of spatial precision across data sets, and performed on par with state-of-the-art on synthetic images in terms of spatial accuracy. We conclude that our method provides a precise method for CR center localization and provides a solution to the data availability problem, which is one of the important common roadblocks in the development of deep learning models for gaze estimation. Due to the superior CR center localization and ease of application, our method has the potential to improve the accuracy and precision of CR-based eye trackers.
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Affiliation(s)
| | - Marcus Nyström
- Lund University Humanities Lab, Lund University, Lund, Sweden
| | - Virmarie Maquiling
- Human-Centered Technologies for Learning, Technical University of Munich, Munich, Germany
| | - Enkelejda Kasneci
- Human-Centered Technologies for Learning, Technical University of Munich, Munich, Germany
| | - Diederick C Niehorster
- MoMiLab, IMT School for Advanced Studies Lucca, Lucca, Italy.
- Department of Psychology, Lund University, Lund, Sweden.
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17
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Jung HJ, Park BH, Kim SH, Hong SC. Integrating magnetic tweezers and single-molecule FRET: A comprehensive approach to studying local and global conformational changes simultaneously. Methods Enzymol 2024; 694:167-189. [PMID: 38492950 DOI: 10.1016/bs.mie.2024.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2024]
Abstract
This chapter presents the integration of magnetic tweezers with single-molecule FRET technology, a significant advancement in the study of nucleic acids and other biological systems. We detail the technical aspects, challenges, and current status of this hybrid technique, which combines the global manipulation and observation capabilities of magnetic tweezers with the local conformational detection of smFRET. This innovative approach enhances our ability to analyze and understand the molecular mechanics of biological systems. The chapter serves as our first formal documentation of this method, offering insights and methodologies developed in our laboratory over the past decade.
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Affiliation(s)
- Hae Jun Jung
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Department of Physics, Korea University, Seoul, Korea
| | - Beom-Hyeon Park
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Department of Physics, Korea University, Seoul, Korea
| | - Sook Ho Kim
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Department of Physics, Korea University, Seoul, Korea; College of Veterinary Medicine, Chungbuk National University, Cheongju, Korea
| | - Seok-Cheol Hong
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Department of Physics, Korea University, Seoul, Korea.
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18
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Zhang C, Muñetón Díaz J, Muster A, Abujetas DR, Froufe-Pérez LS, Scheffold F. Determining intrinsic potentials and validating optical binding forces between colloidal particles using optical tweezers. Nat Commun 2024; 15:1020. [PMID: 38310097 PMCID: PMC11258337 DOI: 10.1038/s41467-024-45162-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 01/17/2024] [Indexed: 02/05/2024] Open
Abstract
Understanding the interactions between small, submicrometer-sized colloidal particles is crucial for numerous scientific disciplines and technological applications. In this study, we employ optical tweezers as a powerful tool to investigate these interactions. We utilize a full image reconstruction technique to achieve high precision in characterizing particle pairs that enable nanometer-scale measurement of their positions. This approach captures intricate details and provides a comprehensive understanding of the spatial arrangement between particles, overcoming previous limitations in resolution. Moreover, our research demonstrates that properly accounting for optical binding forces to determine the intrinsic interaction potential is vital. We employ a discrete dipole approximation approach to calculate optical binding potentials and achieve a good agreement between the calculated and observed binding forces. We incorporate the findings from these simulations into the assessment of the intrinsic interaction potentials and validate our methodology by using short-range depletion attraction induced by micelles as an example.
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Affiliation(s)
- Chi Zhang
- Department of Physics, University of Fribourg, 1700, Fribourg, Switzerland.
| | - José Muñetón Díaz
- Department of Physics, University of Fribourg, 1700, Fribourg, Switzerland
| | - Augustin Muster
- Department of Physics, University of Fribourg, 1700, Fribourg, Switzerland
| | - Diego R Abujetas
- Department of Physics, University of Fribourg, 1700, Fribourg, Switzerland
| | | | - Frank Scheffold
- Department of Physics, University of Fribourg, 1700, Fribourg, Switzerland.
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19
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Jiao M, Danthi P, Yu Y. Cholesterol-Dependent Membrane Deformation by Metastable Viral Capsids Facilitates Entry. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.10.575085. [PMID: 38260524 PMCID: PMC10802578 DOI: 10.1101/2024.01.10.575085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Non-enveloped viruses employ unique entry mechanisms to breach and infect host cells. Understanding these mechanisms is crucial for developing antiviral strategies. Prevailing perspective suggests that non-enveloped viruses release membrane lytic peptides to breach host membranes. However, the precise involvement of the viral capsid in this entry remains elusive. Our study presents direct observations elucidating the dynamically distinctive steps through which metastable reovirus capsids disrupt host lipid membranes as they uncoat into partially hydrophobic intermediate particles. Using both live cells and model membrane systems, our key finding is that reovirus capsids actively deform and permeabilize lipid membranes in a cholesterol-dependent process. Unlike membrane lytic peptides, these metastable viral capsids induce more extensive membrane perturbations, including budding, bridging between adjacent membranes, and complete rupture. Notably, cholesterol enhances subviral particle adsorption, resulting in the formation of pores equivalent to the capsid size. This cholesterol dependence is attributed to the lipid condensing effect, particularly prominent at intermediate cholesterol level. Furthermore, our results reveal a positive correlation between membrane disruption extent and efficiency of viral variants in establishing infection. This study unveils the crucial role of capsid-lipid interaction in non-enveloped virus entry, providing new insights into how cholesterol homeostasis influences virus infection dynamics.
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Affiliation(s)
- Mengchi Jiao
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102
| | - Pranav Danthi
- Department of Biology, Indiana University, Bloomington, IN 47405-7102
| | - Yan Yu
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102
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20
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Greiss F, Lardon N, Schütz L, Barak Y, Daube SS, Weinhold E, Noireaux V, Bar-Ziv R. A genetic circuit on a single DNA molecule as an autonomous dissipative nanodevice. Nat Commun 2024; 15:883. [PMID: 38287055 PMCID: PMC10825189 DOI: 10.1038/s41467-024-45186-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 01/16/2024] [Indexed: 01/31/2024] Open
Abstract
Realizing genetic circuits on single DNA molecules as self-encoded dissipative nanodevices is a major step toward miniaturization of autonomous biological systems. A circuit operating on a single DNA implies that genetically encoded proteins localize during coupled transcription-translation to DNA, but a single-molecule measurement demonstrating this has remained a challenge. Here, we use a genetically encoded fluorescent reporter system with improved temporal resolution and observe the synthesis of individual proteins tethered to a DNA molecule by transient complexes of RNA polymerase, messenger RNA, and ribosome. Against expectations in dilute cell-free conditions where equilibrium considerations favor dispersion, these nascent proteins linger long enough to regulate cascaded reactions on the same DNA. We rationally design a pulsatile genetic circuit by encoding an activator and repressor in feedback on the same DNA molecule. Driven by the local synthesis of only several proteins per hour and gene, the circuit dynamics exhibit enhanced variability between individual DNA molecules, and fluctuations with a broad power spectrum. Our results demonstrate that co-expressional localization, as a nonequilibrium process, facilitates single-DNA genetic circuits as dissipative nanodevices, with implications for nanobiotechnology applications and artificial cell design.
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Affiliation(s)
- Ferdinand Greiss
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel.
| | - Nicolas Lardon
- Department of Chemical Biology, Max Planck Institute for Medical Research, 69120, Heidelberg, Germany
| | - Leonie Schütz
- Institute of Organic Chemistry, RWTH Aachen University, 52056, Aachen, Germany
| | - Yoav Barak
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Shirley S Daube
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Elmar Weinhold
- Institute of Organic Chemistry, RWTH Aachen University, 52056, Aachen, Germany
| | - Vincent Noireaux
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Roy Bar-Ziv
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel.
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21
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Eck E, Moretti B, Schlomann BH, Bragantini J, Lange M, Zhao X, VijayKumar S, Valentin G, Loureiro C, Soroldoni D, Royer LA, Oates AC, Garcia HG. Single-cell transcriptional dynamics in a living vertebrate. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.03.574108. [PMID: 38260569 PMCID: PMC10802376 DOI: 10.1101/2024.01.03.574108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
The ability to quantify transcriptional dynamics in individual cells via live imaging has revolutionized our understanding of gene regulation. However, such measurements are lacking in the context of vertebrate embryos. We addressed this deficit by applying MS2-MCP mRNA labeling to the quantification of transcription in zebrafish, a model vertebrate. We developed a platform of transgenic organisms, light sheet fluorescence microscopy, and optimized image analysis that enables visualization and quantification of MS2 reporters. We used these tools to obtain the first single-cell, real-time measurements of transcriptional dynamics of the segmentation clock. Our measurements challenge the traditional view of smooth clock oscillations and instead suggest a model of discrete transcriptional bursts that are organized in space and time. Together, these results highlight how measuring single-cell transcriptional activity can reveal unexpected features of gene regulation and how this data can fuel the dialogue between theory and experiment.
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Affiliation(s)
- Elizabeth Eck
- Biophysics Graduate Group, University of California at Berkeley, Berkeley, USA
| | - Bruno Moretti
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
- Chan Zuckerberg Biohub – San Francisco, San Francisco, CA, USA
| | - Brandon H. Schlomann
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | | | - Merlin Lange
- Chan Zuckerberg Biohub – San Francisco, San Francisco, CA, USA
| | - Xiang Zhao
- Chan Zuckerberg Biohub – San Francisco, San Francisco, CA, USA
| | | | | | | | | | - Loïc A. Royer
- Chan Zuckerberg Biohub – San Francisco, San Francisco, CA, USA
| | - Andrew C. Oates
- Institute of Bioengineering, EPFL; Lausanne, CH
- Department of Cell and Developmental Biology, UCL; London, UK
- The Francis Crick Institute; London, UK
| | - Hernan G. Garcia
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
- Department of Physics, University of California, Berkeley, CA, USA
- Institute for Quantitative Biosciences-QB3, University of California, Berkeley, CA, USA
- Chan Zuckerberg Biohub – San Francisco, San Francisco, CA, USA
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22
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Qian J, Collette D, Finzi L, Dunlap D. Detecting DNA Loops Using Tethered Particle Motion. Methods Mol Biol 2024; 2694:451-466. [PMID: 37824017 PMCID: PMC10906717 DOI: 10.1007/978-1-0716-3377-9_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
The range of motion of a micron-sized bead tethered by a single polymer provides a dynamic readout of the effective length of the polymer. The excursions of the bead may reflect the intrinsic flexibility and/or topology of the polymer as well as changes due to the action activity of ligands that bind the polymer. This is a simple yet powerful experimental approach to investigate such interactions between DNA and proteins as demonstrated by experiments with the lac repressor. This protein forms a stable, tetrameric oligomer with two binding sites and can produce a loop of DNA between recognition sites separated along the length of a DNA molecule.
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Affiliation(s)
- Jin Qian
- Department of Physics, Emory University, Atlanta, GA, USA
| | - Dylan Collette
- Department of Physics, Emory University, Atlanta, GA, USA
| | - Laura Finzi
- Department of Physics, Emory University, Atlanta, GA, USA
| | - David Dunlap
- Department of Physics, Emory University, Atlanta, GA, USA.
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23
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Roy N, Sood AK, Ganapathy R. Harnessing Viscoelasticity to Suppress Irreversibility Buildup in a Colloidal Stirling Engine. PHYSICAL REVIEW LETTERS 2023; 131:238201. [PMID: 38134791 DOI: 10.1103/physrevlett.131.238201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 07/18/2023] [Accepted: 11/08/2023] [Indexed: 12/24/2023]
Abstract
Typically, the rate at which a heat engine can produce useful work is constrained by the buildup of irreversibility with increasing operating speed. Here, using a recently developed reservoir engineering technique, we designed and quantified the performance of a colloidal Stirling engine operating in a viscoelastic bath. While the bath acts like a viscous fluid in the quasistatic limit, and the engine's performance agrees with equilibrium predictions, on reducing the cycle time to the bath's structural relaxation time, the increasingly elastic response of the bath aids suppress the buildup of irreversibility. We show that the elastic energy stored during the isothermal compression step of the Stirling cycle facilitates quick equilibration in the isothermal expansion step. This results in equilibriumlike efficiencies even for cycle times shorter than the equilibration time of the colloidal particle.
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Affiliation(s)
- Niloyendu Roy
- Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore-560064, India
| | - A K Sood
- Department of Physics, Indian Institute of Science, Bangalore-560012, India
- International Centre for Materials Science, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore-560064, India
| | - Rajesh Ganapathy
- International Centre for Materials Science, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore-560064, India
- School of Advanced Materials (SAMat), Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore-560064, India
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24
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Partridge JD, Dufour Y, Hwang Y, Harshey RM. Flagellar motor remodeling during swarming requires FliL. Mol Microbiol 2023; 120:670-683. [PMID: 37675594 PMCID: PMC10942728 DOI: 10.1111/mmi.15148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 08/18/2023] [Accepted: 08/20/2023] [Indexed: 09/08/2023]
Abstract
FliL is an essential component of the flagellar machinery in some bacteria, but a conditional one in others. The conditional role is for optimal swarming in some bacteria. During swarming, physical forces associated with movement on a surface are expected to exert a higher load on the flagellum, requiring more motor torque to move. FliL was reported to enhance motor output in several bacteria and observed to assemble as a ring around ion-conducting stators that power the motor. In this study we identify a common new function for FliL in diverse bacteria-Escherichia coli, Bacillus subtilis, and Proteus mirabilis. During swarming, all these bacteria show increased cell speed and a skewed motor bias that suppresses cell tumbling. We demonstrate that these altered motor parameters, or "motor remodeling," require FliL. Both swarming and motor remodeling can be restored in an E. coli fliL mutant by complementation with fliL genes from P. mirabilis and B. subtilis, showing conservation of a swarming-associated FliL function across phyla. In addition, we demonstrate that the strong interaction we reported earlier between FliL and the flagellar MS-ring protein FliF is confined to the RBM-3 domain of FliF that links the periplasmic rod to the cytoplasmic C-ring. This interaction may explain several phenotypes associated with the absence of FliL.
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Affiliation(s)
- Jonathan D. Partridge
- Department of Molecular Biosciences and the LaMontagne Center for Infectious Diseases, The University of Texas at Austin, Austin, Texas, USA
| | - Yann Dufour
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - YuneSahng Hwang
- Department of Molecular Biosciences and the LaMontagne Center for Infectious Diseases, The University of Texas at Austin, Austin, Texas, USA
| | - Rasika M. Harshey
- Department of Molecular Biosciences and the LaMontagne Center for Infectious Diseases, The University of Texas at Austin, Austin, Texas, USA
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25
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Zhang P, Ma D, Cheng X, Tsai AP, Tang Y, Gao HC, Fang L, Bi C, Landreth GE, Chubykin AA, Huang F. Deep learning-driven adaptive optics for single-molecule localization microscopy. Nat Methods 2023; 20:1748-1758. [PMID: 37770712 PMCID: PMC10630144 DOI: 10.1038/s41592-023-02029-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 08/23/2023] [Indexed: 09/30/2023]
Abstract
The inhomogeneous refractive indices of biological tissues blur and distort single-molecule emission patterns generating image artifacts and decreasing the achievable resolution of single-molecule localization microscopy (SMLM). Conventional sensorless adaptive optics methods rely on iterative mirror changes and image-quality metrics. However, these metrics result in inconsistent metric responses and thus fundamentally limit their efficacy for aberration correction in tissues. To bypass iterative trial-then-evaluate processes, we developed deep learning-driven adaptive optics for SMLM to allow direct inference of wavefront distortion and near real-time compensation. Our trained deep neural network monitors the individual emission patterns from single-molecule experiments, infers their shared wavefront distortion, feeds the estimates through a dynamic filter and drives a deformable mirror to compensate sample-induced aberrations. We demonstrated that our method simultaneously estimates and compensates 28 wavefront deformation shapes and improves the resolution and fidelity of three-dimensional SMLM through >130-µm-thick brain tissue specimens.
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Affiliation(s)
- Peiyi Zhang
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
| | - Donghan Ma
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN, USA
| | - Xi Cheng
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, USA
| | - Andy P Tsai
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Yu Tang
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, USA
| | - Hao-Cheng Gao
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
| | - Li Fang
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
| | - Cheng Bi
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
| | - Gary E Landreth
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA.
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN, USA.
| | - Alexander A Chubykin
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA.
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, USA.
| | - Fang Huang
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA.
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, USA.
- Purdue Institute of Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN, USA.
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26
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Zheng H, Niu L, Qiu W, Liang D, Long X, Li G, Liu Z, Meng L. The Emergence of Functional Ultrasound for Noninvasive Brain-Computer Interface. RESEARCH (WASHINGTON, D.C.) 2023; 6:0200. [PMID: 37588619 PMCID: PMC10427153 DOI: 10.34133/research.0200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 07/04/2023] [Indexed: 08/18/2023]
Abstract
A noninvasive brain-computer interface is a central task in the comprehensive analysis and understanding of the brain and is an important challenge in international brain-science research. Current implanted brain-computer interfaces are cranial and invasive, which considerably limits their applications. The development of new noninvasive reading and writing technologies will advance substantial innovations and breakthroughs in the field of brain-computer interfaces. Here, we review the theory and development of the ultrasound brain functional imaging and its applications. Furthermore, we introduce latest advancements in ultrasound brain modulation and its applications in rodents, primates, and human; its mechanism and closed-loop ultrasound neuromodulation based on electroencephalograph are also presented. Finally, high-frequency acoustic noninvasive brain-computer interface is prospected based on ultrasound super-resolution imaging and acoustic tweezers.
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Affiliation(s)
- Hairong Zheng
- Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology,
Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Lili Niu
- Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology,
Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Weibao Qiu
- Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology,
Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Dong Liang
- Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology,
Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Xiaojing Long
- Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology,
Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Guanglin Li
- Shenzhen Institute of Advanced Integration Technology, Chinese Academy of Sciences and The Chinese University of Hong Kong, Shenzhen, 518055, China
| | - Zhiyuan Liu
- Shenzhen Institute of Advanced Integration Technology, Chinese Academy of Sciences and The Chinese University of Hong Kong, Shenzhen, 518055, China
| | - Long Meng
- Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology,
Chinese Academy of Sciences, Shenzhen, 518055, China
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27
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Cheng T. Single-molecule localization microscopy based on denoising, interpolation and local maxima. Microscopy (Oxf) 2023; 72:336-342. [PMID: 36412750 DOI: 10.1093/jmicro/dfac065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 11/05/2022] [Accepted: 11/21/2022] [Indexed: 08/05/2023] Open
Abstract
A single fluorescent molecule is highly likely to be located at the center pixel position of a raw image diffused spot in an ideal situation. Even if the molecule and the center pixel position do not completely overlap, they are very close. A single-molecule localization method based on denoising, interpolation and local maxima (DIL) is proposed. The low-resolution raw image is denoised and interpolated, and a new image with a pixel size equal to that of the super-resolution image is attained. The local maxima of the new image are extracted. With this method, it is found that the local maxima positions can be regarded as the fluorescent molecule positions. Simulation results demonstrate that the DIL single-molecule localization accuracy reaches ∼18 nm when the Gaussian noise variance is equal to 0.01. Experimental results demonstrate that the DIL localization methodology is comparable to the Gaussian fitting algorithm and is faster.
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Affiliation(s)
- Tao Cheng
- School of Mechanical and Automotive Engineering, Guangxi University of Science and Technology, No. 268 Avenue Donghuan, Chengzhong District, Liuzhou, Guangxi 545006, P. R. China
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28
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Dong Z, Li S, Duan X, Lowerison MR, Huang C, You Q, Chen S, Zou J, Song P. High-Volume-Rate 3-D Ultrasound Imaging Using Fast-Tilting and Redirecting Reflectors. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2023; 70:799-809. [PMID: 37276113 PMCID: PMC10440128 DOI: 10.1109/tuffc.2023.3282949] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Three-dimensional ultrasound imaging has many advantages over 2-D imaging such as more comprehensive tissue evaluation and less operator dependence. However, developing a low-cost and accessible 3-D ultrasound solution with high volume rate and imaging quality remains a challenging task. Recently, we proposed a 3-D ultrasound imaging technique: fast acoustic steering via tilting electromechanical reflectors (FASTER), which uses a fast-tilting acoustic reflector to steer ultrafast plane waves elevationally to achieve high-volume-rate 3-D imaging with conventional 1-D transducers. However, the initial FASTER implementation requires a water tank for acoustic wave conduction and cannot be conveniently used for regular handheld scanning. To address these limitations, here, we developed a novel ultrasound probe clip-on device that encloses a fast-tilting reflector, a redirecting reflector, and an acoustic wave conduction medium. The new FASTER 3-D imaging device can be easily attached to or removed from clinical ultrasound transducers, allowing rapid transformation from 2-D to 3-D imaging. In vitro B-mode studies demonstrated that the proposed method provided comparable imaging quality to conventional, mechanical-translation-based 3-D imaging while offering a much faster volume rate (e.g., 300 versus ∼ 10 Hz). We also demonstrated 3-D power Doppler (PD) and 3-D super-resolution ultrasound localization microscopy (ULM) with the FASTER device. An in vivo imaging study showed that the FASTER device could clearly visualize the 3-D anatomy of the basilic vein. These results suggest that the newly developed redirecting reflector and the clip-on device could overcome key hurdles for future clinical translation of the FASTER 3-D imaging technology.
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29
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Demeulenaere O, Mateo P, Ferrera R, Chiaroni PM, Bizé A, Dai J, Sambin L, Gallet R, Tanter M, Papadacci C, Ghaleh B, Pernot M. Assessment of coronary microcirculation alterations in a porcine model of no-reflow using ultrasound localization microscopy: a proof of concept study. EBioMedicine 2023; 94:104727. [PMID: 37487415 PMCID: PMC10382870 DOI: 10.1016/j.ebiom.2023.104727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 07/11/2023] [Accepted: 07/11/2023] [Indexed: 07/26/2023] Open
Abstract
BACKGROUND Coronary microvascular obstruction also known as no-reflow phenomenon is a major issue during myocardial infarction that bears important prognostic implications. Alterations of the microvascular network remains however challenging to assess as there is no imaging modality in the clinics that can image directly the coronary microvascular vessels. Ultrasound Localization Microscopy (ULM) imaging was recently introduced to map microvascular flows at high spatial resolution (∼10 μm). In this study, we developed an approach to image alterations of the microvascular coronary flow in ex vivo perfused swine hearts. METHODS A porcine model of myocardial ischemia-reperfusion was used to obtain microvascular coronary alterations and no-reflow. Four female hearts with myocardial infarction in addition to 6 controls were explanted and placed immediately in a dedicated preservation and perfusion box manufactured for ultrasound imaging. Microbubbles (MB) were injected into the vasculature to perform Ultrasound Localization Microscopy (ULM) imaging and a linear ultrasound probe mounted on a motorized device was used to scan the heart on multiple slices. The coronary microvascular anatomy and flow velocity was reconstructed using dedicated ULM algorithms and analyzed quantitatively. FINDINGS We were able to image the coronary microcirculation of ex vivo swine hearts at a resolution of tens of microns and measure flow velocities ranging from 10 mm/s in arterioles up to more than 200 mm/s in epicardial arteries. Under different aortic perfusion pressures, we measured in large arteries of a subset of control hearts an increase of flow velocity from 31 ± 11 mm/s at 87 mmHg to 47 ± 17 mm/s at 132 mmHg (N = 3 hearts, P < 0.05). This increase was compared with a control measurement with a flowmeter in the aorta. We also compared 6 control hearts to 4 hearts in which no-reflow was induced by the occlusion and reperfusion of a coronary artery. Using average MB velocity and average density of MB per unit of surface as two ULM quantitative markers of perfusion, we were able to detect areas of coronary no-reflow in good agreement with a control anatomical pathology analysis of the cardiac tissue. In the no-reflow zone, we measured an average perfusion of 204 ± 305 MB/mm2 compared to 3182 ± 1302 MB/mm2 in the surrounding re-perfused area. INTERPRETATION We demonstrated this approach can directly image and quantify coronary microvascular obstruction and no-reflow on large mammal perfused hearts. This is a first step for noninvasive, quantitative and affordable assessment of the coronary microcirculation function and particularly coronary microvascular anatomy in the infarcted heart. This approach has the potential to be extended to other clinical situations characterized by microvascular dysfunction. FUNDING This study was supported by the French National Research Agency (ANR) under ANR-21-CE19-0002 grant agreement.
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Affiliation(s)
- Oscar Demeulenaere
- Physics for Medicine, ESPCI, INSERM U1273, CNRS UMR 8063, PSL University, Paris, France
| | - Philippe Mateo
- Physics for Medicine, ESPCI, INSERM U1273, CNRS UMR 8063, PSL University, Paris, France
| | - René Ferrera
- CarMeN, 27102 INSERM U1060, INRA U1397, INSA de Lyon, Université Claude Bernard Lyon 1, Université de Lyon, Villeurbanne, France
| | - Paul-Mathieu Chiaroni
- Inserm U955-IMRB, UPEC, Ecole Nationale Vétérinaire d'Alfort, F-94700, Créteil, France; APHP, Hôpitaux Universitaires Henri Mondor, Service de Cardiologie, F-94000, Créteil, France
| | - Alain Bizé
- Inserm U955-IMRB, UPEC, Ecole Nationale Vétérinaire d'Alfort, F-94700, Créteil, France
| | - Jianping Dai
- Inserm U955-IMRB, UPEC, Ecole Nationale Vétérinaire d'Alfort, F-94700, Créteil, France
| | - Lucien Sambin
- Inserm U955-IMRB, UPEC, Ecole Nationale Vétérinaire d'Alfort, F-94700, Créteil, France
| | - Romain Gallet
- Inserm U955-IMRB, UPEC, Ecole Nationale Vétérinaire d'Alfort, F-94700, Créteil, France; APHP, Hôpitaux Universitaires Henri Mondor, Service de Cardiologie, F-94000, Créteil, France
| | - Mickaël Tanter
- Physics for Medicine, ESPCI, INSERM U1273, CNRS UMR 8063, PSL University, Paris, France
| | - Clément Papadacci
- Physics for Medicine, ESPCI, INSERM U1273, CNRS UMR 8063, PSL University, Paris, France.
| | - Bijan Ghaleh
- Inserm U955-IMRB, UPEC, Ecole Nationale Vétérinaire d'Alfort, F-94700, Créteil, France
| | - Mathieu Pernot
- Physics for Medicine, ESPCI, INSERM U1273, CNRS UMR 8063, PSL University, Paris, France
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30
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Partridge JD, Dufour Y, Hwang Y, Harshey RM. Flagellar motor remodeling during swarming requires FliL. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.14.549092. [PMID: 37503052 PMCID: PMC10370021 DOI: 10.1101/2023.07.14.549092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
FliL is an essential component of the flagellar machinery in some bacteria, but a conditional one in others. The conditional role is for optimal swarming in some bacteria. During swarming, physical forces associated with movement on a surface are expected to exert a higher load on the flagellum, requiring more motor torque to move. Bacterial physiology and morphology are also altered during swarming to cope with the challenges of surface navigation. FliL was reported to enhance motor output in several bacteria and observed to assemble as a ring around ion-conducting stators that power the motor. In this study we identify a common new function for FliL in diverse bacteria - Escherichia coli, Bacillus subtilis and Proteus mirabilis . During swarming, all these bacteria show increased cell speed and a skewed motor bias that suppresses cell tumbling. We demonstrate that these altered motor parameters, or 'motor remodeling', require FliL. Both swarming and motor remodeling can be restored in an E. coli fliL mutant by complementation with fliL genes from P. mirabilis and B. subtilis , showing conservation of swarming-associated FliL function across phyla. In addition, we demonstrate that the strong interaction we reported earlier between FliL and the flagellar MS-ring protein FliF is confined to the RBM-3 domain of FliF that links the periplasmic rod to the cytoplasmic C-ring. This interaction may explain several phenotypes associated with the absence of FliL.
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Affiliation(s)
- Jonathan D Partridge
- Department of Molecular Biosciences and the LaMontagne Center for Infectious Diseases The University of Texas at Austin, Austin, Texas, 78712, USA
| | - Yann Dufour
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - YuneSahng Hwang
- Department of Molecular Biosciences and the LaMontagne Center for Infectious Diseases The University of Texas at Austin, Austin, Texas, 78712, USA
| | - Rasika M Harshey
- Department of Molecular Biosciences and the LaMontagne Center for Infectious Diseases The University of Texas at Austin, Austin, Texas, 78712, USA
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31
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Bergkamp MH, Cajigas S, van IJzendoorn LJ, Prins MW. High-Throughput Single-Molecule Sensors: How Can the Signals Be Analyzed in Real Time for Achieving Real-Time Continuous Biosensing? ACS Sens 2023; 8:2271-2281. [PMID: 37216442 PMCID: PMC10294250 DOI: 10.1021/acssensors.3c00245] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 05/05/2023] [Indexed: 05/24/2023]
Abstract
Single-molecule sensors collect statistics of single-molecule interactions, and the resulting data can be used to determine concentrations of analyte molecules. The assays are generally end-point assays and are not designed for continuous biosensing. For continuous biosensing, a single-molecule sensor needs to be reversible, and the signals should be analyzed in real time in order to continuously report output signals, with a well-controlled time delay and measurement precision. Here, we describe a signal processing architecture for real-time continuous biosensing based on high-throughput single-molecule sensors. The key aspect of the architecture is the parallel computation of multiple measurement blocks that enables continuous measurements over an endless time span. Continuous biosensing is demonstrated for a single-molecule sensor with 10,000 individual particles that are tracked as a function of time. The continuous analysis includes particle identification, particle tracking, drift correction, and detection of the discrete timepoints where individual particles switch between bound and unbound states, yielding state transition statistics that relate to the analyte concentration in solution. The continuous real-time sensing and computation were studied for a reversible cortisol competitive immunosensor, showing how the precision and time delay of cortisol monitoring are controlled by the number of analyzed particles and the size of the measurement blocks. Finally, we discuss how the presented signal processing architecture can be applied to various single-molecule measurement methods, allowing these to be developed into continuous biosensors.
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Affiliation(s)
- Max H. Bergkamp
- Department
of Biomedical Engineering, Eindhoven University
of Technology, Eindhoven 5612 AE, The Netherlands
- Institute
for Complex Molecular Systems (ICMS), Eindhoven
University of Technology, Eindhoven 5612 AE, The Netherlands
| | | | - Leo J. van IJzendoorn
- Department
of Applied Physics and Science Education, Eindhoven University of Technology, Eindhoven 5612 AE, The Netherlands
- Institute
for Complex Molecular Systems (ICMS), Eindhoven
University of Technology, Eindhoven 5612 AE, The Netherlands
| | - Menno W.J. Prins
- Department
of Biomedical Engineering, Eindhoven University
of Technology, Eindhoven 5612 AE, The Netherlands
- Department
of Applied Physics and Science Education, Eindhoven University of Technology, Eindhoven 5612 AE, The Netherlands
- Institute
for Complex Molecular Systems (ICMS), Eindhoven
University of Technology, Eindhoven 5612 AE, The Netherlands
- Helia
Biomonitoring, Eindhoven 5612 AR, The Netherlands
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32
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Chen R, Tang X, Zhao Y, Shen Z, Zhang M, Shen Y, Li T, Chung CHY, Zhang L, Wang J, Cui B, Fei P, Guo Y, Du S, Yao S. Single-frame deep-learning super-resolution microscopy for intracellular dynamics imaging. Nat Commun 2023; 14:2854. [PMID: 37202407 DOI: 10.1038/s41467-023-38452-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 04/28/2023] [Indexed: 05/20/2023] Open
Abstract
Single-molecule localization microscopy (SMLM) can be used to resolve subcellular structures and achieve a tenfold improvement in spatial resolution compared to that obtained by conventional fluorescence microscopy. However, the separation of single-molecule fluorescence events that requires thousands of frames dramatically increases the image acquisition time and phototoxicity, impeding the observation of instantaneous intracellular dynamics. Here we develop a deep-learning based single-frame super-resolution microscopy (SFSRM) method which utilizes a subpixel edge map and a multicomponent optimization strategy to guide the neural network to reconstruct a super-resolution image from a single frame of a diffraction-limited image. Under a tolerable signal density and an affordable signal-to-noise ratio, SFSRM enables high-fidelity live-cell imaging with spatiotemporal resolutions of 30 nm and 10 ms, allowing for prolonged monitoring of subcellular dynamics such as interplays between mitochondria and endoplasmic reticulum, the vesicle transport along microtubules, and the endosome fusion and fission. Moreover, its adaptability to different microscopes and spectra makes it a useful tool for various imaging systems.
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Affiliation(s)
- Rong Chen
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Xiao Tang
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Yuxuan Zhao
- School of Optical and Electronic Information, Huazhong University of Science and Technology, 430074, Wuhan, China
| | - Zeyu Shen
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Meng Zhang
- School of Optical and Electronic Information, Huazhong University of Science and Technology, 430074, Wuhan, China
| | - Yusheng Shen
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Tiantian Li
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Casper Ho Yin Chung
- Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Lijuan Zhang
- School of Pharmaceutical Sciences, Guizhou University, 550025, Guizhou, China
| | - Ji Wang
- Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Binbin Cui
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Peng Fei
- School of Optical and Electronic Information, Huazhong University of Science and Technology, 430074, Wuhan, China
| | - Yusong Guo
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong, China.
| | - Shengwang Du
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Hong Kong, China.
- Department of Physics, The Hong Kong University of Science and Technology, Hong Kong, China.
- Department of Physics, The University of Texas at Dallas, Richardson, TX, 75080, USA.
| | - Shuhuai Yao
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Hong Kong, China.
- Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Hong Kong, China.
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33
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Takei Y, Yang Y, White J, Yun J, Prasad M, Ombelets LJ, Schindler S, Cai L. High-resolution spatial multi-omics reveals cell-type specific nuclear compartments. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.07.539762. [PMID: 37214923 PMCID: PMC10197539 DOI: 10.1101/2023.05.07.539762] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The mammalian nucleus is compartmentalized by diverse subnuclear structures. These subnuclear structures, marked by nuclear bodies and histone modifications, are often cell-type specific and affect gene regulation and 3D genome organization1-3. Understanding nuclear organization requires identifying the molecular constituents of subnuclear structures and mapping their associations with specific genomic loci in individual cells, within complex tissues. Here, we introduce two-layer DNA seqFISH+, which allows simultaneous mapping of 100,049 genomic loci, together with nascent transcriptome for 17,856 genes and a diverse set of immunofluorescently labeled subnuclear structures all in single cells in cell lines and adult mouse cerebellum. Using these multi-omics datasets, we showed that repressive chromatin compartments are more variable by cell type than active compartments. We also discovered a single exception to this rule: an RNA polymerase II (RNAPII)-enriched compartment was associated with long, cell-type specific genes (> 200kb), in a manner distinct from nuclear speckles. Further, our analysis revealed that cell-type specific facultative and constitutive heterochromatin compartments marked by H3K27me3 and H4K20me3 are enriched at specific genes and gene clusters, respectively, and shape radial chromosomal positioning and inter-chromosomal interactions in neurons and glial cells. Together, our results provide a single-cell high-resolution multi-omics view of subnuclear compartments, associated genomic loci, and their impacts on gene regulation, directly within complex tissues.
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Affiliation(s)
- Yodai Takei
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Yujing Yang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Jonathan White
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Jina Yun
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Meera Prasad
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | | | | | - Long Cai
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
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34
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Wu RJ, Clark AM, Cox MA, Intoy J, Jolly PC, Zhao Z, Rucci M. High-resolution eye-tracking via digital imaging of Purkinje reflections. J Vis 2023; 23:4. [PMID: 37140912 PMCID: PMC10166114 DOI: 10.1167/jov.23.5.4] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023] Open
Abstract
Reliably measuring eye movements and determining where the observer looks are fundamental needs in vision science. A classical approach to achieve high-resolution oculomotor measurements is the so-called dual Purkinje image (DPI) method, a technique that relies on the relative motion of the reflections generated by two distinct surfaces in the eye, the cornea and the back of the lens. This technique has been traditionally implemented in fragile and difficult to operate analog devices, which have remained exclusive use of specialized oculomotor laboratories. Here we describe progress on the development of a digital DPI, a system that builds on recent advances in digital imaging to enable fast, highly precise eye-tracking without the complications of previous analog devices. This system integrates an optical setup with no moving components with a digital imaging module and dedicated software on a fast processing unit. Data from both artificial and human eyes demonstrate subarcminute resolution at 1 kHz. Furthermore, when coupled with previously developed gaze-contingent calibration methods, this system enables localization of the line of sight within a few arcminutes.
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Affiliation(s)
- Ruei-Jr Wu
- Department of Brain & Cognitive Sciences and Center for Visual Science, University of Rochester, 310 Meliora Hall, Rochester, NY, USA
| | - Ashley M Clark
- Department of Brain & Cognitive Sciences and Center for Visual Science, University of Rochester, 310 Meliora Hall, Rochester, NY, USA
| | - Michele A Cox
- Department of Brain & Cognitive Sciences and Center for Visual Science, University of Rochester, 310 Meliora Hall, Rochester, NY, USA
| | - Janis Intoy
- Department of Brain & Cognitive Sciences and Center for Visual Science, University of Rochester, 310 Meliora Hall, Rochester, NY, USA
| | - Paul C Jolly
- Department of Brain & Cognitive Sciences and Center for Visual Science, University of Rochester, 310 Meliora Hall, Rochester, NY, USA
| | - Zhetuo Zhao
- Department of Brain & Cognitive Sciences and Center for Visual Science, University of Rochester, 310 Meliora Hall, Rochester, NY, USA
| | - Michele Rucci
- Department of Brain & Cognitive Sciences and Center for Visual Science, University of Rochester, 310 Meliora Hall, Rochester, NY, USA
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35
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Wang Z, Chen G, Wang S, Su X. Three-dimensional deep regression-based light scattering imaging system for nanoscale exosome analysis. BIOMEDICAL OPTICS EXPRESS 2023; 14:2055-2067. [PMID: 37206116 PMCID: PMC10191644 DOI: 10.1364/boe.483791] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/27/2023] [Accepted: 02/11/2023] [Indexed: 05/21/2023]
Abstract
Exosomes are extracellular vesicles that serve as promising intrinsic nanoscale biomarkers for disease diagnosis and treatment. Nanoparticle analysis technology is widely used in the field of exosome study. However, the common particle analysis methods are usually complex, subjective, and not robust. Here, we develop a three-dimensional (3D) deep regression-based light scattering imaging system for nanoscale particle analysis. Our system solves the problem of object focusing in common methods and acquires light scattering images of label-free nanoparticles as small as 41 nm in diameter. We develop a new method for nanoparticle sizing with 3D deep regression, where the 3D time series Brownian motion data of single nanoparticles are input as a whole, and sizes are output automatically for both entangled and untangled nanoparticles. Exosomes from the normal and cancer liver cell lineage cells are observed and automatically differentiated by our system. The 3D deep regression-based light scattering imaging system is expected to be widely used in the field of nanoparticle analysis and nanomedicine.
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Affiliation(s)
- Zhuo Wang
- School of Microelectronics, Shandong University, Jinan, 250101, China
- Institute of Biomedical Engineering, School of Control Science and Engineering, Shandong University, Jinan, 250061, China
| | - Gao Chen
- School of Microelectronics, Shandong University, Jinan, 250101, China
| | - Shuanglian Wang
- Department of Physiology, School of Medicine, Shandong University, Jinan, 250012, China
| | - Xuantao Su
- School of Microelectronics, Shandong University, Jinan, 250101, China
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36
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Altman LE, Grier DG. Machine learning enables precise holographic characterization of colloidal materials in real time. SOFT MATTER 2023; 19:3002-3014. [PMID: 37017639 DOI: 10.1039/d2sm01283a] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Holographic particle characterization uses in-line holographic video microscopy to track and characterize individual colloidal particles dispersed in their native fluid media. Applications range from fundamental research in statistical physics to product development in biopharmaceuticals and medical diagnostic testing. The information encoded in a hologram can be extracted by fitting to a generative model based on the Lorenz-Mie theory of light scattering. Treating hologram analysis as a high-dimensional inverse problem has been exceptionally successful, with conventional optimization algorithms yielding nanometer precision for a typical particle's position and part-per-thousand precision for its size and index of refraction. Machine learning previously has been used to automate holographic particle characterization by detecting features of interest in multi-particle holograms and estimating the particles' positions and properties for subsequent refinement. This study presents an updated end-to-end neural-network solution called CATCH (Characterizing and Tracking Colloids Holographically) whose predictions are fast, precise, and accurate enough for many real-world high-throughput applications and can reliably bootstrap conventional optimization algorithms for the most demanding applications. The ability of CATCH to learn a representation of Lorenz-Mie theory that fits within a diminutive 200 kB hints at the possibility of developing a greatly simplified formulation of light scattering by small objects.
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Affiliation(s)
- Lauren E Altman
- Department of Physics and Center for Soft Matter Research, New York University, New York, NY 10003, USA.
| | - David G Grier
- Department of Physics and Center for Soft Matter Research, New York University, New York, NY 10003, USA.
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37
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Wolf A, Volz-Rakebrand P, Balke J, Alexiev U. Diffusion Analysis of NAnoscopic Ensembles: A Tracking-Free Diffusivity Analysis for NAnoscopic Ensembles in Biological Samples and Nanotechnology. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2206722. [PMID: 36670094 DOI: 10.1002/smll.202206722] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/16/2022] [Indexed: 06/17/2023]
Abstract
The rapid development of microscopic techniques over the past decades enables the establishment of single molecule fluorescence imaging as a powerful tool in biological and biomedical sciences. Single molecule fluorescence imaging allows to study the chemical, physicochemical, and biological properties of target molecules or particles by tracking their molecular position in the biological environment and determining their dynamic behavior. However, the precise determination of particle distribution and diffusivities is often challenging due to high molecule/particle densities, fast diffusion, and photobleaching/blinking of the fluorophore. A novel, accurate, and fast statistical analysis tool, Diffusion Analysis of NAnoscopic Ensembles (DANAE), that solves all these obstacles is introduced. DANAE requires no approximations or any a priori input regarding unknown system-inherent parameters, such as background distributions; a requirement that is vitally important when studying the behavior of molecules/particles in living cells. The superiority of DANAE with various data from simulations is demonstrated. As experimental applications of DANAE, membrane receptor diffusion in its natural membrane environment, and cargo mobility/distribution within nanostructured lipid nanoparticles are presented. Finally, the method is extended to two-color channel fluorescence microscopy.
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Affiliation(s)
- Alexander Wolf
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany
| | - Pierre Volz-Rakebrand
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany
| | - Jens Balke
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany
| | - Ulrike Alexiev
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany
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38
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Dong Z, Li S, Duan X, Lowerison MR, Huang C, You Q, Chen S, Zou J, Song P. High Volume Rate 3-D Ultrasound Imaging Using Fast-Tilting and Redirecting Reflectors. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.07.531439. [PMID: 36945643 PMCID: PMC10028918 DOI: 10.1101/2023.03.07.531439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Abstract
3-D ultrasound imaging has many advantages over 2-D imaging such as more comprehensive tissue evaluation and less operator dependence. Although many 3-D ultrasound imaging techniques have been developed in the last several decades, a low-cost and accessible solution with high imaging volume rate and imaging quality remains elusive. Recently we proposed a new, high volume rate 3-D ultrasound imaging technique: Fast Acoustic Steering via Tilting Electromechanical Reflectors (FASTER), which uses a water-immersible and fast-tilting acoustic reflector to steer ultrafast plane waves in the elevational direction to achieve high volume rate 3-D ultrasound imaging with conventional 1-D array transducers. However, the initial implementation of FASTER imaging only involves a single fast-tilting acoustic reflector, which is inconvenient to use because the probe cannot be held in the regular upright position. Also, conventional FASTER imaging can only be performed inside a water tank because of the necessity of using water for acoustic conduction. To address these limitations of conventional FASTER, here we developed a novel ultrasound probe clip-on device that encloses a fast-tilting reflector, a redirecting reflector, and an acoustic wave conduction medium. The new FASTER 3-D imaging device can be easily attached to or removed from clinical ultrasound transducers, allowing rapid transformation from 2-D to 3-D ultrasound imaging. In vitro B-mode imaging studies demonstrated that the proposed method provided comparable imaging quality (e.g., spatial resolution and contrast-to-noise ratio) to conventional, mechanical-translation-based 3-D imaging while providing a much faster 3-D volume rate (e.g., 300 Hz vs ∼10 Hz). In addition to B-mode imaging, we also demonstrated 3-D power Doppler imaging and 3-D super-resolution ultrasound localization microscopy with the newly developed FASTER device. An in vivo imaging study showed that the FASTER device could clearly visualize the 3-D anatomy of the basilic vein of a healthy volunteer, and customized beamforming was implemented to accommodate the speed of sound difference between the acoustic medium and the imaging object (e.g., soft tissue). These results suggest that the newly developed redirecting reflector and the clip-on device could overcome key hurdles for future clinical translation of the FASTER 3-D imaging technology.
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39
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Eisentraut M, Sabri A, Kress H. The spatial resolution limit of phagocytosis. Biophys J 2023; 122:868-879. [PMID: 36703557 PMCID: PMC10027436 DOI: 10.1016/j.bpj.2023.01.030] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 01/05/2023] [Accepted: 01/23/2023] [Indexed: 01/27/2023] Open
Abstract
Antibody-opsonized bacteria interact with Fc receptors in macrophages and trigger signaling cascades, which induce phagocytosis. The signaling pathways ultimately lead to actin polymerization that induces the protrusion of the membrane around the bacterium until it is completely engulfed. Although many proteins involved in the phagocytic cup formation have already been identified, it is still unclear how far the initial stimulus created by the bacterium-cell contact propagates in the cell. We hypothesize that this spreading distance is closely related to the spatial resolution limit of phagocytosis, the smallest distance in which two stimuli can be differentiated. Here, we probe this resolution limit by using holographic optical tweezers to attach pairs of immunoglobulin G-coated polystyrene microparticles (as models for opsonized bacteria) to murine macrophages in distances ranging from zero to several micrometers. By using 2-μm-sized particles, we found that the particles can be internalized jointly into one phagosome if they are attached to the cell very close together, but that they are taken up separately if they are attached far from each other. To explain this, we developed a model of the signaling process, which predicts the probabilities for separate uptake for different particle sizes and distances using cellular parameters including the average receptor distance. We tested the model by measuring the separate uptake probabilities for particles with a diameter of 1 to 3 μm and for cells with reduced numbers of Fcγ receptors and found very good agreement. Our model shows that the phagocytic uptake behavior can be explained by assuming an effective phagocytic signaling range of about 500 nm. Interestingly, this value corresponds to the lower size limit of phagocytosis. Our work provides quantitative access to spatial parameters of cellular signaling during phagocytosis and thereby contributes to a more quantitative understanding of cellular information processing.
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Affiliation(s)
| | - Adal Sabri
- Biological Physics, University of Bayreuth, Bayreuth, Germany
| | - Holger Kress
- Biological Physics, University of Bayreuth, Bayreuth, Germany.
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40
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Simulation-based inference for non-parametric statistical comparison of biomolecule dynamics. PLoS Comput Biol 2023; 19:e1010088. [PMID: 36730436 PMCID: PMC9928078 DOI: 10.1371/journal.pcbi.1010088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 02/14/2023] [Accepted: 01/16/2023] [Indexed: 02/04/2023] Open
Abstract
Numerous models have been developed to account for the complex properties of the random walks of biomolecules. However, when analysing experimental data, conditions are rarely met to ensure model identification. The dynamics may simultaneously be influenced by spatial and temporal heterogeneities of the environment, out-of-equilibrium fluxes and conformal changes of the tracked molecules. Recorded trajectories are often too short to reliably discern such multi-scale dynamics, which precludes unambiguous assessment of the type of random walk and its parameters. Furthermore, the motion of biomolecules may not be well described by a single, canonical random walk model. Here, we develop a two-step statistical testing scheme for comparing biomolecule dynamics observed in different experimental conditions without having to identify or make strong prior assumptions about the model generating the recorded random walks. We first train a graph neural network to perform simulation-based inference and thus learn a rich summary statistics vector describing individual trajectories. We then compare trajectories obtained in different biological conditions using a non-parametric maximum mean discrepancy (MMD) statistical test on their so-obtained summary statistics. This procedure allows us to characterise sets of random walks regardless of their generating models, without resorting to model-specific physical quantities or estimators. We first validate the relevance of our approach on numerically simulated trajectories. This demonstrates both the statistical power of the MMD test and the descriptive power of the learnt summary statistics compared to estimates of physical quantities. We then illustrate the ability of our framework to detect changes in α-synuclein dynamics at synapses in cultured cortical neurons, in response to membrane depolarisation, and show that detected differences are largely driven by increased protein mobility in the depolarised state, in agreement with previous findings. The method provides a means of interpreting the differences it detects in terms of single trajectory characteristics. Finally, we emphasise the interest of performing various comparisons to probe the heterogeneity of experimentally acquired datasets at different levels of granularity (e.g., biological replicates, fields of view, and organelles).
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41
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Ortiz-Orruño U, Quidant R, van Hulst NF, Liebel M, Ortega Arroyo J. Simultaneous Sizing and Refractive Index Analysis of Heterogeneous Nanoparticle Suspensions. ACS NANO 2023; 17:221-229. [PMID: 36525614 PMCID: PMC9835976 DOI: 10.1021/acsnano.2c06883] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 12/13/2022] [Indexed: 05/25/2023]
Abstract
Rapid and reliable characterization of heterogeneous nanoparticle suspensions is a key technology across the nanosciences. Although approaches exist for homogeneous samples, they are often unsuitable for polydisperse suspensions, as particles of different sizes and compositions can lead to indistinguishable signals at the detector. Here, we introduce holographic nanoparticle tracking analysis, holoNTA, as a straightforward methodology that decouples size and material refractive index contributions. HoloNTA is applicable to any heterogeneous nanoparticle sample and has the sensitivity to measure the intrinsic heterogeneity of the sample. Specifically, we combined high dynamic range k-space imaging with holographic 3D single-particle tracking. This strategy enables long-term tracking by extending the imaging volume and delivers precise and accurate estimates of both scattering amplitude and diffusion coefficient of individual nanoparticles, from which particle refractive index and hydrodynamic size are determined. We specifically demonstrate, by simulations and experiments, that irrespective of localization uncertainty and size, the sizing sensitivity is improved as our extended detection volume yields considerably longer particle trajectories than previously reported by comparable technologies. As validation, we measured both homogeneous and heterogeneous suspensions of nanoparticles in the 40-250 nm size range and further monitored protein corona formation, where we identified subtle differences between the nanoparticle-protein complexes derived from avidin, bovine serum albumin, and streptavidin. We foresee that our approach will find many applications of both fundamental and applied nature where routine quantification and sizing of nanoparticles are required.
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Affiliation(s)
- Unai Ortiz-Orruño
- ICFO,
Institut de Ciencies Fotoniques, The Barcelona Institute of Science
and Technology, Castelldefels08860, Spain
| | - Romain Quidant
- Nanophotonic
Systems Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, Zurich8092, Switzerland
| | - Niek F. van Hulst
- ICFO,
Institut de Ciencies Fotoniques, The Barcelona Institute of Science
and Technology, Castelldefels08860, Spain
- ICREA,
Institució Catalana de Recerca i Estudis Avançats, Barcelona08010, Spain
| | - Matz Liebel
- ICFO,
Institut de Ciencies Fotoniques, The Barcelona Institute of Science
and Technology, Castelldefels08860, Spain
| | - Jaime Ortega Arroyo
- Nanophotonic
Systems Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, Zurich8092, Switzerland
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42
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Naylor A, Zheng Y, Jiao Y, Sun B. Micromechanical remodeling of the extracellular matrix by invading tumors: anisotropy and heterogeneity. SOFT MATTER 2022; 19:9-16. [PMID: 36503977 PMCID: PMC9867555 DOI: 10.1039/d2sm01100j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Altered tissue mechanics is an important signature of invasive solid tumors. While the phenomena have been extensively studied by measuring the bulk rheology of the extracellular matrix (ECM) surrounding tumors, micromechanical remodeling at the cellular scale remains poorly understood. By combining holographic optical tweezers and confocal microscopy on in vitro tumor models, we show that the micromechanics of collagen ECM surrounding an invading tumor demonstrate directional anisotropy, spatial heterogeneity and significant variations in time as tumors invade. To test the cellular mechanisms of ECM micromechanical remodeling, we construct a simple computational model and verify its predictions with experiments. We find that collective force generation of a tumor stiffens the ECM and leads to anisotropic local mechanics such that the extension direction is more rigid than the compression direction. ECM degradation by cell-secreted matrix metalloproteinase softens the ECM, and active traction forces from individual disseminated cells re-stiffen the matrix. Together, these results identify plausible biophysical mechanisms responsible for the remodeled ECM micromechanics surrounding an invading tumor.
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Affiliation(s)
- Austin Naylor
- Department of Physics, Oregon State University, Corvallis, OR, USA.
| | - Yu Zheng
- Department of Physics, Arizona State University, Tempe, AZ, USA.
| | - Yang Jiao
- Department of Physics, Arizona State University, Tempe, AZ, USA.
- Materials Science and Engineering, Arizona State University, Tempe, AZ, USA
| | - Bo Sun
- Department of Physics, Oregon State University, Corvallis, OR, USA.
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43
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Midtvedt B, Pineda J, Skärberg F, Olsén E, Bachimanchi H, Wesén E, Esbjörner EK, Selander E, Höök F, Midtvedt D, Volpe G. Single-shot self-supervised object detection in microscopy. Nat Commun 2022; 13:7492. [PMID: 36470883 PMCID: PMC9722899 DOI: 10.1038/s41467-022-35004-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 11/15/2022] [Indexed: 12/12/2022] Open
Abstract
Object detection is a fundamental task in digital microscopy, where machine learning has made great strides in overcoming the limitations of classical approaches. The training of state-of-the-art machine-learning methods almost universally relies on vast amounts of labeled experimental data or the ability to numerically simulate realistic datasets. However, experimental data are often challenging to label and cannot be easily reproduced numerically. Here, we propose a deep-learning method, named LodeSTAR (Localization and detection from Symmetries, Translations And Rotations), that learns to detect microscopic objects with sub-pixel accuracy from a single unlabeled experimental image by exploiting the inherent roto-translational symmetries of this task. We demonstrate that LodeSTAR outperforms traditional methods in terms of accuracy, also when analyzing challenging experimental data containing densely packed cells or noisy backgrounds. Furthermore, by exploiting additional symmetries we show that LodeSTAR can measure other properties, e.g., vertical position and polarizability in holographic microscopy.
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Affiliation(s)
- Benjamin Midtvedt
- grid.8761.80000 0000 9919 9582Department of Physics, University of Gothenburg, Gothenburg, Sweden
| | - Jesús Pineda
- grid.8761.80000 0000 9919 9582Department of Physics, University of Gothenburg, Gothenburg, Sweden
| | - Fredrik Skärberg
- grid.8761.80000 0000 9919 9582Department of Physics, University of Gothenburg, Gothenburg, Sweden
| | - Erik Olsén
- grid.5371.00000 0001 0775 6028Department of Physics, Chalmers University of Technology, Gothenburg, Sweden
| | - Harshith Bachimanchi
- grid.8761.80000 0000 9919 9582Department of Physics, University of Gothenburg, Gothenburg, Sweden
| | - Emelie Wesén
- grid.5371.00000 0001 0775 6028Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Elin K. Esbjörner
- grid.5371.00000 0001 0775 6028Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Erik Selander
- grid.8761.80000 0000 9919 9582Department of Marine Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Fredrik Höök
- grid.5371.00000 0001 0775 6028Department of Physics, Chalmers University of Technology, Gothenburg, Sweden
| | - Daniel Midtvedt
- grid.8761.80000 0000 9919 9582Department of Physics, University of Gothenburg, Gothenburg, Sweden
| | - Giovanni Volpe
- grid.8761.80000 0000 9919 9582Department of Physics, University of Gothenburg, Gothenburg, Sweden
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44
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Bahry E, Breimann L, Zouinkhi M, Epstein L, Kolyvanov K, Mamrak N, King B, Long X, Harrington KIS, Lionnet T, Preibisch S. RS-FISH: precise, interactive, fast, and scalable FISH spot detection. Nat Methods 2022; 19:1563-1567. [PMID: 36396787 PMCID: PMC9718671 DOI: 10.1038/s41592-022-01669-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 09/28/2022] [Indexed: 11/18/2022]
Abstract
Fluorescent in-situ hybridization (FISH)-based methods extract spatially resolved genetic and epigenetic information from biological samples by detecting fluorescent spots in microscopy images, an often challenging task. We present Radial Symmetry-FISH (RS-FISH), an accurate, fast, and user-friendly software for spot detection in two- and three-dimensional images. RS-FISH offers interactive parameter tuning and readily scales to large datasets and image volumes of cleared or expanded samples using distributed processing on workstations, clusters, or the cloud. RS-FISH maintains high detection accuracy and low localization error across a wide range of signal-to-noise ratios, a key feature for single-molecule FISH, spatial transcriptomics, or spatial genomics applications.
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Affiliation(s)
- Ella Bahry
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin Institute for Medical Systems Biology (BIMSB), Berlin, Germany
| | - Laura Breimann
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin Institute for Medical Systems Biology (BIMSB), Berlin, Germany
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY, USA
| | - Marwan Zouinkhi
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin Institute for Medical Systems Biology (BIMSB), Berlin, Germany
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Leo Epstein
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin Institute for Medical Systems Biology (BIMSB), Berlin, Germany
- Helmholtz Imaging Platform, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Klim Kolyvanov
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin Institute for Medical Systems Biology (BIMSB), Berlin, Germany
| | - Nicholas Mamrak
- Institute for Systems Genetics and Department of Cell Biology, NYU School of Medicine, New York, NY, USA
| | - Benjamin King
- Institute for Systems Genetics and Department of Cell Biology, NYU School of Medicine, New York, NY, USA
| | - Xi Long
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Kyle I S Harrington
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin Institute for Medical Systems Biology (BIMSB), Berlin, Germany.
- Helmholtz Imaging Platform, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
| | - Timothée Lionnet
- Institute for Systems Genetics and Department of Cell Biology, NYU School of Medicine, New York, NY, USA.
- Department of Bioengineering, NYU Tandon School of Engineering, Brooklyn, NY, USA.
| | - Stephan Preibisch
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA.
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45
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Bellingham-Johnstun K, Commer B, Levesque B, Tyree ZL, Laplante C. Imp2p forms actin-dependent clusters and imparts stiffness to the contractile ring. Mol Biol Cell 2022; 33:ar145. [PMID: 36287824 PMCID: PMC9727792 DOI: 10.1091/mbc.e22-06-0221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The contractile ring must anchor to the plasma membrane and cell wall to transmit its tension. F-BAR domain containing proteins including Imp2p and Cdc15p in fission yeast are likely candidate anchoring proteins based on their mutant phenotypes. Cdc15p is a node component, links the actin bundle to the plasma membrane, recruits Bgs1p to the division plane, prevents contractile ring sliding, and contributes to the stiffness of the contractile ring. Less is known about Imp2p. We found that similarly to Cdc15p, Imp2p contributes to the stiffness of the contractile ring and assembles into protein clusters. Imp2p clusters contain approximately eight Imp2p dimers and depend on the actin network for their stability at the division plane. Importantly, Imp2p and Cdc15p reciprocally affect the amount of each other in the contractile ring, indicating that the two proteins influence each other during cytokinesis, which may partially explain their similar phenotypes.
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Affiliation(s)
| | - Blake Commer
- Department of Molecular Biomedical Sciences, North Carolina State University, Raleigh, NC 27607
| | - Brié Levesque
- Department of Molecular Biomedical Sciences, North Carolina State University, Raleigh, NC 27607
| | - Zoe L Tyree
- Department of Molecular Biomedical Sciences, North Carolina State University, Raleigh, NC 27607
| | - Caroline Laplante
- Department of Molecular Biomedical Sciences, North Carolina State University, Raleigh, NC 27607
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46
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Kashchuk AV, Perederiy O, Caldini C, Gardini L, Pavone FS, Negriyko AM, Capitanio M. Particle Localization Using Local Gradients and Its Application to Nanometer Stabilization of a Microscope. ACS NANO 2022; 17:1344-1354. [PMID: 36383436 PMCID: PMC9878972 DOI: 10.1021/acsnano.2c09787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Accepted: 11/10/2022] [Indexed: 06/16/2023]
Abstract
Particle localization plays a fundamental role in advanced biological techniques such as single-molecule tracking, superresolution microscopy, and manipulation by optical and magnetic tweezers. Such techniques require fast and accurate particle localization algorithms as well as nanometer-scale stability of the microscope. Here, we present a universal method for three-dimensional localization of single labeled and unlabeled particles based on local gradient calculation of particle images. The method outperforms state-of-the-art localization techniques in high-noise conditions, and it is capable of 3D nanometer accuracy localization of nano- and microparticles with sub-millisecond calculation time. By localizing a fixed particle as fiducial mark and running a feedback loop, we demonstrate its applicability for active drift correction in sensitive nanomechanical measurements such as optical trapping and superresolution imaging. A multiplatform open software package comprising a set of tools for local gradient calculation in brightfield, darkfield, and fluorescence microscopy is shared for ready use by the scientific community.
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Affiliation(s)
- Anatolii V. Kashchuk
- Department
of Physics and Astronomy, University of
Florence, Via Sansone 1, Sesto Fiorentino, 50019, Italy
- LENS, European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, Sesto Fiorentino, 50019, Italy
| | | | - Chiara Caldini
- LENS, European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, Sesto Fiorentino, 50019, Italy
| | - Lucia Gardini
- LENS, European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, Sesto Fiorentino, 50019, Italy
- National
Institute of Optics, National Research Council, Largo Fermi 6, 50125, Florence, Italy
| | - Francesco Saverio Pavone
- Department
of Physics and Astronomy, University of
Florence, Via Sansone 1, Sesto Fiorentino, 50019, Italy
- LENS, European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, Sesto Fiorentino, 50019, Italy
- National
Institute of Optics, National Research Council, Largo Fermi 6, 50125, Florence, Italy
| | | | - Marco Capitanio
- Department
of Physics and Astronomy, University of
Florence, Via Sansone 1, Sesto Fiorentino, 50019, Italy
- LENS, European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, Sesto Fiorentino, 50019, Italy
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47
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Han K, Hua X, Vasani V, Kim GAR, Liu W, Takayama S, Jia S. 3D super-resolution live-cell imaging with radial symmetry and Fourier light-field microscopy. BIOMEDICAL OPTICS EXPRESS 2022; 13:5574-5584. [PMID: 36733732 PMCID: PMC9872894 DOI: 10.1364/boe.471967] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 09/23/2022] [Accepted: 09/26/2022] [Indexed: 06/18/2023]
Abstract
Live-cell imaging reveals the phenotypes and mechanisms of cellular function and their dysfunction that underscore cell physiology, development, and pathology. Here, we report a 3D super-resolution live-cell microscopy method by integrating radiality analysis and Fourier light-field microscopy (rad-FLFM). We demonstrated the method using various live-cell specimens, including actins in Hela cells, microtubules in mammary organoid cells, and peroxisomes in COS-7 cells. Compared with conventional wide-field microscopy, rad-FLFM realizes scanning-free, volumetric 3D live-cell imaging with sub-diffraction-limited resolution of ∼150 nm (x-y) and 300 nm (z), milliseconds volume acquisition time, six-fold extended depth of focus of ∼6 µm, and low photodamage. The method provides a promising avenue to explore spatiotemporal-challenging subcellular processes in a wide range of cell biological research.
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Affiliation(s)
- Keyi Han
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA
| | - Xuanwen Hua
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA
| | - Vishwa Vasani
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Ge-Ah R. Kim
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Wenhao Liu
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA
| | - Shuichi Takayama
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Shu Jia
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, 30332, USA
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48
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Tian D, Qu Z, Lai T, Zhu G. A prediction model for nanoparticle diffusion behavior in fibrous materials considering steric and hydrodynamic resistances. Phys Chem Chem Phys 2022; 24:24394-24403. [PMID: 36189674 DOI: 10.1039/d2cp03397f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Precise prediction of the hindered diffusion behavior of electroneutral particles in fibrous media plays a critical role in the development of drugs, polymer membranes, and porous electrodes. However, the random microstructure and unknown coupling relationship of multiple resistance mechanisms lead to the lack of a universal prediction model. In this work, a dual-resistance model is proposed by reconstructed pore-scale simulations, which presents the coexistence of steric and hydrodynamic resistances in the multiplication form. The simulation results show that the relationship between steric resistance and structural parameters (porosity, fiber radius, and particle radius) is exponential, while that for hydrodynamic resistance is polynomial. The dominant diffusion resistance is found to change from hydrodynamic to steric resistance with a decrease in porosity. The fluorescent polystyrene microsphere diffusivity in a series of SiO2 fibrous media is determined by single-particle tracking experiments, quantitatively confirming the dual-resistance model. The present model can be used for rapid diffusivity prediction and fibrous membrane and drug design.
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Affiliation(s)
- Di Tian
- MOE Key Laboratory of Thermal-Fluid Science and Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, 710049, China.
| | - Zhiguo Qu
- MOE Key Laboratory of Thermal-Fluid Science and Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, 710049, China.
| | - Tao Lai
- MOE Key Laboratory of Thermal-Fluid Science and Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, 710049, China.
| | - Guodong Zhu
- Department of Urology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, P. R. China
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49
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Yu Y, Zhang Z, Walpole GFW, Yu Y. Kinetics of phagosome maturation is coupled to their intracellular motility. Commun Biol 2022; 5:1014. [PMID: 36163370 PMCID: PMC9512794 DOI: 10.1038/s42003-022-03988-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 09/12/2022] [Indexed: 11/09/2022] Open
Abstract
Immune cells degrade internalized pathogens in phagosomes through sequential biochemical changes. The degradation must be fast enough for effective infection control. The presumption is that each phagosome degrades cargos autonomously with a distinct but stochastic kinetic rate. However, here we show that the degradation kinetics of individual phagosomes is not stochastic but coupled to their intracellular motility. By engineering RotSensors that are optically anisotropic, magnetic responsive, and fluorogenic in response to degradation activities in phagosomes, we monitored cargo degradation kinetics in single phagosomes simultaneously with their translational and rotational dynamics. We show that phagosomes that move faster centripetally are more likely to encounter and fuse with lysosomes, thereby acidifying faster and degrading cargos more efficiently. The degradation rates increase nearly linearly with the translational and rotational velocities of phagosomes. Our results indicate that the centripetal motion of phagosomes functions as a clock for controlling the progression of cargo degradation.
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Affiliation(s)
- Yanqi Yu
- Department of Chemistry, Indiana University, Bloomington, IN, 47405-7102, USA
| | - Zihan Zhang
- Department of Chemistry, Indiana University, Bloomington, IN, 47405-7102, USA
| | - Glenn F W Walpole
- Program in Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Yan Yu
- Department of Chemistry, Indiana University, Bloomington, IN, 47405-7102, USA.
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50
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Heckert A, Dahal L, Tjian R, Darzacq X. Recovering mixtures of fast-diffusing states from short single-particle trajectories. eLife 2022; 11:e70169. [PMID: 36066004 PMCID: PMC9451534 DOI: 10.7554/elife.70169] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 08/04/2022] [Indexed: 12/15/2022] Open
Abstract
Single-particle tracking (SPT) directly measures the dynamics of proteins in living cells and is a powerful tool to dissect molecular mechanisms of cellular regulation. Interpretation of SPT with fast-diffusing proteins in mammalian cells, however, is complicated by technical limitations imposed by fast image acquisition. These limitations include short trajectory length due to photobleaching and shallow depth of field, high localization error due to the low photon budget imposed by short integration times, and cell-to-cell variability. To address these issues, we investigated methods inspired by Bayesian nonparametrics to infer distributions of state parameters from SPT data with short trajectories, variable localization precision, and absence of prior knowledge about the number of underlying states. We discuss the advantages and disadvantages of these approaches relative to other frameworks for SPT analysis.
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Affiliation(s)
- Alec Heckert
- Department of Molecular and Cell Biology, Li Ka Shing Center for Biomedical and Health Sciences, University of California, BerkeleyBerkeleyUnited States
| | - Liza Dahal
- Department of Molecular and Cell Biology, Li Ka Shing Center for Biomedical and Health Sciences, University of California, BerkeleyBerkeleyUnited States
- CIRM Center of Excellence, University of California, BerkeleyBerkeleyUnited States
| | - Robert Tjian
- CIRM Center of Excellence, University of California, BerkeleyBerkeleyUnited States
- Howard Hughes Medical InstituteBerkeleyUnited States
| | - Xavier Darzacq
- Department of Molecular and Cell Biology, Li Ka Shing Center for Biomedical and Health Sciences, University of California, BerkeleyBerkeleyUnited States
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