1
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Martinez KN, Gerstner NC, Yang SJ, Miller EW. Extended voltage imaging in cardiomyocytes with a triplet state quencher-stabilized silicon rhodamine. Bioorg Med Chem Lett 2024; 109:129842. [PMID: 38844174 DOI: 10.1016/j.bmcl.2024.129842] [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: 09/29/2023] [Revised: 05/17/2024] [Accepted: 06/02/2024] [Indexed: 06/18/2024]
Abstract
Voltage imaging of cardiac electrophysiology with voltage-sensitive dyes has long been a powerful complement to traditional methods like patch-clamp electrophysiology. Chemically synthesized voltage sensitive fluorophores offer flexibility for imaging in sensitive samples like human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs), since they do not require genetic transformation of the sample. One serious concern for any fluorescent voltage indicator, whether chemically synthesized or genetically encoded, is phototoxicity. We have been exploring self-healing fluorophores that use triplet state quenchers (TSQs) as a means to reduce the already low phototoxicity of VoltageFluor dyes developed in our lab. We previously showed that conjugation of the TSQ cyclooctatetraene (COT) to a fluorescein based VoltageFluor dye substantially reduced phototoxicity. Here, we show that this approach can be applied to far-red Silicon rhodamine dyes. COT-conjugated Si-rhodamines show improved photostability and reduced phototoxicity in hiPSC-CMs compared to the unmodified dye. This enables imaging of hiPSC-CMs for up to 30 min with continuous illumination. We show that this effect is mediated by a combination of reduced singlet oxygen production and lower loading in the cellular membrane. We discuss future applications and avenues of improvement for TSQ-stabilized VoltageFluor dyes.
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Affiliation(s)
- Kayli N Martinez
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720-1460, USA
| | - Nels C Gerstner
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720-1460, USA
| | - Samantha J Yang
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720-1460, USA
| | - Evan W Miller
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720-1460, USA; Department of Molecular & Cell Biology, University of California, Berkeley, Berkeley, CA 94720-1460, USA; Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720-1460, USA.
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2
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Pamungkas KKP, Fureraj I, Assies L, Sakai N, Mercier V, Chen XX, Vauthey E, Matile S. Core-Alkynylated Fluorescent Flippers: Altered Ultrafast Photophysics to Track Thick Membranes. Angew Chem Int Ed Engl 2024; 63:e202406204. [PMID: 38758302 DOI: 10.1002/anie.202406204] [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: 04/01/2024] [Revised: 05/06/2024] [Accepted: 05/16/2024] [Indexed: 05/18/2024]
Abstract
Fluorescent flippers have been introduced as small-molecule probes to image membrane tension in living systems. This study describes the design, synthesis, spectroscopic and imaging properties of flippers that are elongated by one and two alkynes inserted between the push and the pull dithienothiophene domains. The resulting mechanophores combine characteristics of flippers, reporting on physical compression in the ground state, and molecular rotors, reporting on torsional motion in the excited state, to take their photophysics to new level of sophistication. Intensity ratios in broadened excitation bands from differently twisted conformers of core-alkynylated flippers thus report on mechanical compression. Lifetime boosts from ultrafast excited-state planarization and lifetime drops from competitive intersystem crossing into triplet states report on viscosity. In standard lipid bilayer membranes, core-alkynylated flippers are too long for one leaflet and tilt or extend into disordered interleaflet space, which preserves rotor-like torsional disorder and thus weak, blue-shifted fluorescence. Flipper-like planarization occurs only in highly ordered membranes of matching leaflet thickness, where they light up and selectively report on these thick membranes with red-shifted, sharpened excitation maxima, high intensity and long lifetime.
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Affiliation(s)
| | - Ina Fureraj
- Department of Physical Chemistry, University of Geneva, Geneva, Switzerland
| | - Lea Assies
- Department of Organic Chemistry, University of Geneva, Geneva, Switzerland
| | - Naomi Sakai
- Department of Organic Chemistry, University of Geneva, Geneva, Switzerland
| | | | - Xiao-Xiao Chen
- Department of Organic Chemistry, University of Geneva, Geneva, Switzerland
| | - Eric Vauthey
- Department of Physical Chemistry, University of Geneva, Geneva, Switzerland
| | - Stefan Matile
- Department of Organic Chemistry, University of Geneva, Geneva, Switzerland
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3
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Roy D, Michalet X, Miller EW, Weiss S. Towards optical measurements of membrane potential values in Bacillus subtilis using fluorescence lifetime. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.13.598880. [PMID: 38915670 PMCID: PMC11195253 DOI: 10.1101/2024.06.13.598880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Membrane potential (MP) changes can provide a simple readout of bacterial functional and metabolic state or stress levels. While several optical methods exist for measuring fast changes in MP in excitable cells, there is a dearth of such methods for absolute and precise measurements of steady-state membrane potentials (MPs) in bacterial cells. Conventional electrode-based methods for the measurement of MP are not suitable for calibrating optical methods in small bacterial cells. While optical measurement based on Nernstian indicators have been successfully used, they do not provide absolute or precise quantification of MP or its changes. We present a novel, calibrated MP recording approach to address this gap. Our method is based on (i) a unique VoltageFluor (VF) optical transducer, whose fluorescence lifetime varies as a function of MP via photoinduced electron transfer (PeT) and (ii) a quantitative phasor-FLIM analysis for high-throughput readout. This method allows MP changes to be easily recorded, quantified and visualized. Using our preliminary Bacillus subtilis-specific MP versus VF lifetime calibration, we estimated the MP for unperturbed B. subtilis cells to be -65 mV and that for chemically depolarized cells as -14 mV. Our work paves the way for deeper insights into bacterial electrophysiology and bioelectricity research.
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Affiliation(s)
- Debjit Roy
- UCLA-DOE Institute for Genomics and Proteomics, Department of Biological Chemistry, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Xavier Michalet
- Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, CA 90095, USA
- California Nano Systems Institute, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Evan W. Miller
- Departments of Chemistry, Molecular and Cell Biology, Helen Wills Neuroscience Institute, University of California at Berkeley, CA 94720, USA
| | - Shimon Weiss
- UCLA-DOE Institute for Genomics and Proteomics, Department of Biological Chemistry, University of California at Los Angeles, Los Angeles, CA 90095, USA
- Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, CA 90095, USA
- Department of Physiology, University of California at Los Angeles, Los Angeles, CA 90095, USA
- California Nano Systems Institute, University of California at Los Angeles, Los Angeles, CA 90095, USA
- Department of Physics, Institute for Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 52900, Israel
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4
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Gest AMM, Lazzari-Dean JR, Ortiz G, Yaeger-Weiss SK, Boggess SC, Miller EW. A red-emitting carborhodamine for monitoring and measuring membrane potential. Proc Natl Acad Sci U S A 2024; 121:e2315264121. [PMID: 38551837 PMCID: PMC10998576 DOI: 10.1073/pnas.2315264121] [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: 10/06/2023] [Accepted: 01/25/2024] [Indexed: 04/02/2024] Open
Abstract
Biological membrane potentials, or voltages, are a central facet of cellular life. Optical methods to visualize cellular membrane voltages with fluorescent indicators are an attractive complement to traditional electrode-based approaches, since imaging methods can be high throughput, less invasive, and provide more spatial resolution than electrodes. Recently developed fluorescent indicators for voltage largely report changes in membrane voltage by monitoring voltage-dependent fluctuations in fluorescence intensity. However, it would be useful to be able to not only monitor changes but also measure values of membrane potentials. This study discloses a fluorescent indicator which can address both. We describe the synthesis of a sulfonated tetramethyl carborhodamine fluorophore. When this carborhodamine is conjugated with an electron-rich, methoxy (-OMe) containing phenylenevinylene molecular wire, the resulting molecule, CRhOMe, is a voltage-sensitive fluorophore with red/far-red fluorescence. Using CRhOMe, changes in cellular membrane potential can be read out using fluorescence intensity or lifetime. In fluorescence intensity mode, CRhOMe tracks fast-spiking neuronal action potentials (APs) with greater signal-to-noise than state-of-the-art BeRST 1 (another voltage-sensitive fluorophore). CRhOMe can also measure values of membrane potential. The fluorescence lifetime of CRhOMe follows a single exponential decay, substantially improving the quantification of membrane potential values using fluorescence lifetime imaging microscopy (FLIM). The combination of red-shifted excitation and emission, mono-exponential decay, and high voltage sensitivity enable fast FLIM recording of APs in cardiomyocytes. The ability to both monitor and measure membrane potentials with red light using CRhOMe makes it an important approach for studying biological voltages.
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Affiliation(s)
| | | | - Gloria Ortiz
- Department of Chemistry, University of California, Berkeley, CA 94720
| | | | - Steven C Boggess
- Department of Chemistry, University of California, Berkeley, CA 94720
| | - Evan W Miller
- Department of Chemistry, University of California, Berkeley, CA 94720
- Department of Molecular & Cell Biology, University of California, Berkeley, CA 94720
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720
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5
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Turnbull JL, Miller EW. An open and shut case? Chemistry to control xanthene dyes. TRENDS IN CHEMISTRY 2024; 6:164-172. [PMID: 39036609 PMCID: PMC11257214 DOI: 10.1016/j.trechm.2024.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/23/2024]
Abstract
Fluorescent dyes are an indispensable part of the scientific enterprise. Xanthene-based fluorophores, like fluorescein and rhodamine, have been in continual use across numerous fields since their invention in the late 19th century. Modern methods to synthesize and expand the scope of xanthene dye chemistry have enabled new colors, enhanced stability, and improved brightness. Modifications to the 3-position of xanthene dyes have been, until recently, less well-explored. Here, we discuss how small changes to the identity of the substituent at the 3-position of fluoresceins and rhodamines can profoundly alter the properties of xanthene dyes, with the potential to unlock new applications at the interface of chemistry and biology.
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Affiliation(s)
- Joshua L. Turnbull
- Department of Chemistry, University of California, Berkeley, CA 94720, United States of America
| | - Evan W. Miller
- Department of Chemistry, University of California, Berkeley, CA 94720, United States of America
- Department of Molecular & Cell Biology, University of California, Berkeley, CA 94720, United States of America
- Helen Wills Neuroscience Institute University of California, Berkeley, CA 94720, United States of America
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6
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Lam CK, Fung LY, Wang Y. Orientation and Membrane Partition Free Energy of PeT-Based Voltage-Sensitive Dyes from Molecular Simulations. J Phys Chem B 2024; 128:2734-2744. [PMID: 38459942 PMCID: PMC10961725 DOI: 10.1021/acs.jpcb.3c08090] [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: 12/11/2023] [Revised: 02/19/2024] [Accepted: 02/20/2024] [Indexed: 03/11/2024]
Abstract
Voltage measurement via small-molecule fluorescent indicators is a valuable approach in deciphering complex dynamics in electrically excitable cells. However, our understanding of various physicochemical properties governing the performance of fluorescent voltage sensors based on the photoinduced electron transfer (PeT) mechanism remains incomplete. Here, through extensive molecular dynamics and free energy calculations, we systematically examine the orientation and membrane partition of three PeT-based voltage-sensing VoltageFluor (VF) dyes in different lipid environment. We show that the symmetry of the molecular scaffold and the net charge of the hydrophilic headgroup of a given VF dye dominate its orientation and membrane partition, respectively. Our work provides a mechanistic understanding of the physical properties contributing to the voltage sensitivity, signal-to-noise ratio, as well as membrane distribution of VF dyes and sheds light onto rational design principles of PeT-based fluorescent probes in general.
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Affiliation(s)
- Chun Kei Lam
- Department of Physics, The
Chinese University
of Hong Kong, Shatin, Hong Kong SAR, China
| | - Lap Yan Fung
- Department of Physics, The
Chinese University
of Hong Kong, Shatin, Hong Kong SAR, China
| | - Yi Wang
- Department of Physics, The
Chinese University
of Hong Kong, Shatin, Hong Kong SAR, China
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7
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Jiang G, Liu H, Liu H, Ke G, Ren TB, Xiong B, Zhang XB, Yuan L. Chemical Approaches to Optimize the Properties of Organic Fluorophores for Imaging and Sensing. Angew Chem Int Ed Engl 2024; 63:e202315217. [PMID: 38081782 DOI: 10.1002/anie.202315217] [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: 10/09/2023] [Indexed: 12/30/2023]
Abstract
Organic fluorophores are indispensable tools in cells, tissue and in vivo imaging, and have enabled much progress in the wide range of biological and biomedical fields. However, many available dyes suffer from insufficient performances, such as short absorption and emission wavelength, low brightness, poor stability, small Stokes shift, and unsuitable permeability, restricting their application in advanced imaging technology and complex imaging. Over the past two decades, many efforts have been made to improve these performances of fluorophores. Starting with the luminescence principle of fluorophores, this review clarifies the mechanisms of the insufficient performance for traditional fluorophores to a certain extent, systematically summarizes the modified approaches of optimizing properties, highlights the typical applications of the improved fluorophores in imaging and sensing, and indicates existing problems and challenges in this area. This progress not only proves the significance of improving fluorophores properties, but also provide a theoretical guidance for the development of high-performance fluorophores.
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Affiliation(s)
- Gangwei Jiang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, 410082, Changsha, P. R. China
| | - Han Liu
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, 410082, Changsha, P. R. China
| | - Hong Liu
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, 410082, Changsha, P. R. China
| | - Guoliang Ke
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, 410082, Changsha, P. R. China
| | - Tian-Bing Ren
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, 410082, Changsha, P. R. China
| | - Bin Xiong
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, 410082, Changsha, P. R. China
| | - Xiao-Bing Zhang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, 410082, Changsha, P. R. China
| | - Lin Yuan
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, 410082, Changsha, P. R. China
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8
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Ma J, Sun R, Xia K, Xia Q, Liu Y, Zhang X. Design and Application of Fluorescent Probes to Detect Cellular Physical Microenvironments. Chem Rev 2024; 124:1738-1861. [PMID: 38354333 DOI: 10.1021/acs.chemrev.3c00573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2024]
Abstract
The microenvironment is indispensable for functionality of various biomacromolecules, subcellular compartments, living cells, and organisms. In particular, physical properties within the biological microenvironment could exert profound effects on both the cellular physiology and pathology, with parameters including the polarity, viscosity, pH, and other relevant factors. There is a significant demand to directly visualize and quantitatively measure the fluctuation in the cellular microenvironment with spatiotemporal resolution. To satisfy this need, analytical methods based on fluorescence probes offer great opportunities due to the facile, sensitive, and dynamic detection that these molecules could enable in varying biological settings from in vitro samples to live animal models. Herein, we focus on various types of small molecule fluorescent probes for the detection and measurement of physical parameters of the microenvironment, including pH, polarity, viscosity, mechanical force, temperature, and electron potential. For each parameter, we primarily describe the chemical mechanisms underlying how physical properties are correlated with changes of various fluorescent signals. This review provides both an overview and a perspective for the development of small molecule fluorescent probes to visualize the dynamic changes in the cellular environment, to expand the knowledge for biological process, and to enrich diagnostic tools for human diseases.
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Affiliation(s)
- Junbao Ma
- Department of Chemistry and Research Center for Industries of the Future, Westlake University, 600 Dunyu Road, Hangzhou 310030, Zhejiang Province, China
- Westlake Laboratory of Life Sciences and Biomedicine, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou 310030, Zhejiang Province, China
| | - Rui Sun
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
- University of the Chinese Academy of Sciences, 19 A Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Kaifu Xia
- Department of Chemistry and Research Center for Industries of the Future, Westlake University, 600 Dunyu Road, Hangzhou 310030, Zhejiang Province, China
- Westlake Laboratory of Life Sciences and Biomedicine, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou 310030, Zhejiang Province, China
| | - Qiuxuan Xia
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
- University of the Chinese Academy of Sciences, 19 A Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Yu Liu
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
- State Key Laboratory of Medical Proteomics, National Chromatographic R. & A. Center, Chinese Academy of Sciences Dalian Liaoning 116023, China
| | - Xin Zhang
- Department of Chemistry and Research Center for Industries of the Future, Westlake University, 600 Dunyu Road, Hangzhou 310030, Zhejiang Province, China
- Westlake Laboratory of Life Sciences and Biomedicine, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
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9
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Giammanco G, Veneziano R, Dunn B, Such N, Cressman JR, Chitnis PV. DNA-Based Near-Infrared Voltage Sensors. ACS Sens 2023; 8:3680-3686. [PMID: 37725687 PMCID: PMC10616843 DOI: 10.1021/acssensors.3c01429] [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: 07/13/2023] [Accepted: 09/14/2023] [Indexed: 09/21/2023]
Abstract
Indocyanine green (ICG) is an FDA approved dye widely used for fluorescence imaging in research, surgical navigation, and medical diagnostics. However, ICG has a few drawbacks, such as concentration-dependent aggregation and absorbance, nonspecific cellular targeting, and rapid photobleaching. Here, we report a novel DNA-based nanosensor platform that utilizes monomers of ICG and cholesterol. Using DNA origami, we can attach ICG to a DNA structure, maintaining its concentration, preserving its near-infrared (NIR) absorbance, and allowing attachment of targeting moieties. We characterized the nanosensors' absorbance, stability in blood, and voltage sensing in vitro. This study presents a novel DNA-based ICG nanosensor platform for cellular voltage sensing for future in vivo applications.
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Affiliation(s)
- Giovanni Giammanco
- Department
of Bioengineering, George Mason University, Fairfax, Virginia 22030, United States
| | - Remi Veneziano
- Department
of Bioengineering, George Mason University, Fairfax, Virginia 22030, United States
- Institute
for Advanced Biomedical Research, George
Mason University, Manassas, Virginia 20110, United States
| | - Bryce Dunn
- Department
of Bioengineering, George Mason University, Fairfax, Virginia 22030, United States
| | - Nicholas Such
- Department
of Bioengineering, George Mason University, Fairfax, Virginia 22030, United States
| | - John R. Cressman
- Department
of Physics, George Mason University, Fairfax, Virginia 22030, United States
| | - Parag V. Chitnis
- Department
of Bioengineering, George Mason University, Fairfax, Virginia 22030, United States
- Center
for Adaptive Systems for Brain-body Interactions, George Mason University, Fairfax, Virginia 22030, United States
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10
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Fontana S, Caramazza L, Marracino P, Cuenca Ortolá I, Colella M, Dolciotti N, Paffi A, Gisbert Roca F, Ivashchenko S, Más Estellés J, Consales C, Balucani M, Apollonio F, Liberti M. Electric field bridging-effect in electrified microfibrils' scaffolds. Front Bioeng Biotechnol 2023; 11:1264406. [PMID: 37954020 PMCID: PMC10634785 DOI: 10.3389/fbioe.2023.1264406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 10/03/2023] [Indexed: 11/14/2023] Open
Abstract
Introduction: The use of biocompatible scaffolds combined with the implantation of neural stem cells, is increasingly being investigated to promote the regeneration of damaged neural tissue, for instance, after a Spinal Cord Injury (SCI). In particular, aligned Polylactic Acid (PLA) microfibrils' scaffolds are capable of supporting cells, promoting their survival and guiding their differentiation in neural lineage to repair the lesion. Despite its biocompatible nature, PLA is an electrically insulating material and thus it could be detrimental for increasingly common scaffolds' electric functionalization, aimed at accelerating the cellular processes. In this context, the European RISEUP project aims to combine high intense microseconds pulses and DC stimulation with neurogenesis, supported by a PLA microfibrils' scaffold. Methods: In this paper a numerical study on the effect of microfibrils' scaffolds on the E-field distribution, in planar interdigitated electrodes, is presented. Realistic microfibrils' 3D CAD models have been built to carry out a numerical dosimetry study, through Comsol Multiphysics software. Results: Under a voltage of 10 V, microfibrils redistribute the E-field values focalizing the field streamlines in the spaces between the fibers, allowing the field to pass and reach maximum values up to 100 kV/m and values comparable with the bare electrodes' device (without fibers). Discussion: Globally the median E-field inside the scaffolded electrodes is the 90% of the nominal field, allowing an adequate cells' exposure.
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Affiliation(s)
- Sara Fontana
- BioEM Lab, Department of Information Engineering, Electronics and Telecommunications (DIET), Sapienza University of Rome, Rome, Italy
- Center for Life Nano- & Neuro-Science, Fondazione Istituto Italiano di Tecnologia (IIT), Rome, Italy
| | - Laura Caramazza
- BioEM Lab, Department of Information Engineering, Electronics and Telecommunications (DIET), Sapienza University of Rome, Rome, Italy
- Center for Life Nano- & Neuro-Science, Fondazione Istituto Italiano di Tecnologia (IIT), Rome, Italy
| | | | - Irene Cuenca Ortolá
- Center for Biomaterials and Tissue Engineering, Universitat Politècnica de València, Valencia, Spain
| | - Micol Colella
- BioEM Lab, Department of Information Engineering, Electronics and Telecommunications (DIET), Sapienza University of Rome, Rome, Italy
| | - Noemi Dolciotti
- BioEM Lab, Department of Information Engineering, Electronics and Telecommunications (DIET), Sapienza University of Rome, Rome, Italy
| | - Alessandra Paffi
- BioEM Lab, Department of Information Engineering, Electronics and Telecommunications (DIET), Sapienza University of Rome, Rome, Italy
| | - Fernando Gisbert Roca
- Center for Biomaterials and Tissue Engineering, Universitat Politècnica de València, Valencia, Spain
| | - Sergiy Ivashchenko
- Center for Biomaterials and Tissue Engineering, Universitat Politècnica de València, Valencia, Spain
| | - Jorge Más Estellés
- Center for Biomaterials and Tissue Engineering, Universitat Politècnica de València, Valencia, Spain
| | - Claudia Consales
- Division of Health Protection Technologies, ENEA-Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Rome, Italy
| | | | - Francesca Apollonio
- BioEM Lab, Department of Information Engineering, Electronics and Telecommunications (DIET), Sapienza University of Rome, Rome, Italy
- Center for Life Nano- & Neuro-Science, Fondazione Istituto Italiano di Tecnologia (IIT), Rome, Italy
| | - Micaela Liberti
- BioEM Lab, Department of Information Engineering, Electronics and Telecommunications (DIET), Sapienza University of Rome, Rome, Italy
- Center for Life Nano- & Neuro-Science, Fondazione Istituto Italiano di Tecnologia (IIT), Rome, Italy
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11
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Gest AMM, Lazzari-Dean JR, Ortiz G, Yaeger-Weiss SK, Boggess SC, Miller EW. A red-emitting carborhodamine for monitoring and measuring membrane potential. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.06.561080. [PMID: 37873283 PMCID: PMC10592620 DOI: 10.1101/2023.10.06.561080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Biological membrane potentials, or voltages, are a central facet of cellular life. Optical methods to visualize cellular membrane voltages with fluorescent indicators are an attractive complement to traditional electrode-based approaches, since imaging methods can be high throughput, less invasive, and provide more spatial resolution than electrodes. Recently developed fluorescent indicators for voltage largely report changes in membrane voltage by monitoring voltage-dependent fluctuations in fluorescence intensity. However, it would be useful to be able to not only monitor changes, but also measure values of membrane potentials. This study discloses a new fluorescent indicator which can address both. We describe the synthesis of a new sulfonated tetramethyl carborhodamine fluorophore. When this carborhodamine is conjugated with an electron-rich, methoxy (-OMe) containing phenylenevinylene molecular wire, the resulting molecule, CRhOMe, is a voltage-sensitive fluorophore with red/far-red fluorescence. Using CRhOMe, changes in cellular membrane potential can be read out using fluorescence intensity or lifetime. In fluorescence intensity mode, CRhOMe tracks fast-spiking neuronal action potentials with greater signal-to-noise than state-of-the-art BeRST (another voltage-sensitive fluorophore). CRhOMe can also measure values of membrane potential. The fluorescence lifetime of CRhOMe follows a single exponential decay, substantially improving the quantification of membrane potential values using fluorescence lifetime imaging microscopy (FLIM). The combination of red-shifted excitation and emission, mono-exponential decay, and high voltage sensitivity enable fast FLIM recording of action potentials in cardiomyocytes. The ability to both monitor and measure membrane potentials with red light using CRhOMe makes it an important approach for studying biological voltages.
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Affiliation(s)
| | | | - Gloria Ortiz
- Department of Chemistry, University of California, Berkeley
| | | | | | - Evan W Miller
- Department of Chemistry, University of California, Berkeley
- Department of Molecular & Cell Biology, University of California, Berkeley
- Helen Wills Neuroscience Institute, University of California, Berkeley
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12
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Chen XX, Gomila RM, García-Arcos JM, Vonesch M, Gonzalez-Sanchis N, Roux A, Frontera A, Sakai N, Matile S. Fluorogenic In Situ Thioacetalization: Expanding the Chemical Space of Fluorescent Probes, Including Unorthodox, Bifurcated, and Mechanosensitive Chalcogen Bonds. JACS AU 2023; 3:2557-2565. [PMID: 37772186 PMCID: PMC10523495 DOI: 10.1021/jacsau.3c00364] [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: 07/07/2023] [Revised: 08/09/2023] [Accepted: 08/09/2023] [Indexed: 09/30/2023]
Abstract
Progress with fluorescent flippers, small-molecule probes to image membrane tension in living systems, has been limited by the effort needed to synthesize the twisted push-pull mechanophore. Here, we move to a higher oxidation level to introduce a new design paradigm that allows the screening of flipper probes rapidly, at best in situ. Late-stage clicking of thioacetals and acetals allows simultaneous attachment of targeting units and interfacers and exploration of the critical chalcogen-bonding donor at the same time. Initial studies focus on plasma membrane targeting and develop the chemical space of acetals and thioacetals, from acyclic amino acids to cyclic 1,3-heterocycles covering dioxanes as well as dithiolanes, dithianes, and dithiepanes, derived also from classics in biology like cysteine, lipoic acid, asparagusic acid, DTT, and epidithiodiketopiperazines. From the functional point of view, the sensitivity of membrane tension imaging in living cells could be doubled, with lifetime differences in FLIM images increasing from 0.55 to 1.11 ns. From a theoretical point of view, the complexity of mechanically coupled chalcogen bonding is explored, revealing, among others, intriguing bifurcated chalcogen bonds.
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Affiliation(s)
- Xiao-Xiao Chen
- Department
of Organic Chemistry, University of Geneva, 1211 Geneva, Switzerland
| | - Rosa M. Gomila
- Departament
de Química, Universitat de les Illes
Balears, SP-07122 Palma de Mallorca, Spain
| | | | - Maxime Vonesch
- Department
of Organic Chemistry, University of Geneva, 1211 Geneva, Switzerland
| | | | - Aurelien Roux
- Department
of Biochemistry, University of Geneva, 1211 Geneva, Switzerland
| | - Antonio Frontera
- Departament
de Química, Universitat de les Illes
Balears, SP-07122 Palma de Mallorca, Spain
| | - Naomi Sakai
- Department
of Organic Chemistry, University of Geneva, 1211 Geneva, Switzerland
| | - Stefan Matile
- Department
of Organic Chemistry, University of Geneva, 1211 Geneva, Switzerland
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13
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Almasri RM, Ladouceur F, Mawad D, Esrafilzadeh D, Firth J, Lehmann T, Poole-Warren LA, Lovell NH, Al Abed A. Emerging trends in the development of flexible optrode arrays for electrophysiology. APL Bioeng 2023; 7:031503. [PMID: 37692375 PMCID: PMC10491464 DOI: 10.1063/5.0153753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 08/08/2023] [Indexed: 09/12/2023] Open
Abstract
Optical-electrode (optrode) arrays use light to modulate excitable biological tissues and/or transduce bioelectrical signals into the optical domain. Light offers several advantages over electrical wiring, including the ability to encode multiple data channels within a single beam. This approach is at the forefront of innovation aimed at increasing spatial resolution and channel count in multichannel electrophysiology systems. This review presents an overview of devices and material systems that utilize light for electrophysiology recording and stimulation. The work focuses on the current and emerging methods and their applications, and provides a detailed discussion of the design and fabrication of flexible arrayed devices. Optrode arrays feature components non-existent in conventional multi-electrode arrays, such as waveguides, optical circuitry, light-emitting diodes, and optoelectronic and light-sensitive functional materials, packaged in planar, penetrating, or endoscopic forms. Often these are combined with dielectric and conductive structures and, less frequently, with multi-functional sensors. While creating flexible optrode arrays is feasible and necessary to minimize tissue-device mechanical mismatch, key factors must be considered for regulatory approval and clinical use. These include the biocompatibility of optical and photonic components. Additionally, material selection should match the operating wavelength of the specific electrophysiology application, minimizing light scattering and optical losses under physiologically induced stresses and strains. Flexible and soft variants of traditionally rigid photonic circuitry for passive optical multiplexing should be developed to advance the field. We evaluate fabrication techniques against these requirements. We foresee a future whereby established telecommunications techniques are engineered into flexible optrode arrays to enable unprecedented large-scale high-resolution electrophysiology systems.
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Affiliation(s)
- Reem M. Almasri
- Graduate School of Biomedical Engineering, UNSW, Sydney, NSW 2052, Australia
| | | | - Damia Mawad
- School of Materials Science and Engineering, UNSW, Sydney, NSW 2052, Australia
| | - Dorna Esrafilzadeh
- Graduate School of Biomedical Engineering, UNSW, Sydney, NSW 2052, Australia
| | - Josiah Firth
- Australian National Fabrication Facility, UNSW, Sydney, NSW 2052, Australia
| | - Torsten Lehmann
- School of Electrical Engineering and Telecommunications, UNSW, Sydney, NSW 2052, Australia
| | | | | | - Amr Al Abed
- Graduate School of Biomedical Engineering, UNSW, Sydney, NSW 2052, Australia
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14
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Kervadec A, Kezos J, Ni H, Yu M, Marchant J, Spiering S, Kannan S, Kwon C, Andersen P, Bodmer R, Grandi E, Ocorr K, Colas AR. Multiplatform modeling of atrial fibrillation identifies phospholamban as a central regulator of cardiac rhythm. Dis Model Mech 2023; 16:dmm049962. [PMID: 37293707 PMCID: PMC10387351 DOI: 10.1242/dmm.049962] [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: 10/25/2022] [Accepted: 05/26/2023] [Indexed: 06/10/2023] Open
Abstract
Atrial fibrillation (AF) is a common and genetically inheritable form of cardiac arrhythmia; however, it is currently not known how these genetic predispositions contribute to the initiation and/or maintenance of AF-associated phenotypes. One major barrier to progress is the lack of experimental systems to investigate the effects of gene function on rhythm parameters in models with human atrial and whole-organ relevance. Here, we assembled a multi-model platform enabling high-throughput characterization of the effects of gene function on action potential duration and rhythm parameters using human induced pluripotent stem cell-derived atrial-like cardiomyocytes and a Drosophila heart model, and validation of the findings using computational models of human adult atrial myocytes and tissue. As proof of concept, we screened 20 AF-associated genes and identified phospholamban loss of function as a top conserved hit that shortens action potential duration and increases the incidence of arrhythmia phenotypes upon stress. Mechanistically, our study reveals that phospholamban regulates rhythm homeostasis by functionally interacting with L-type Ca2+ channels and NCX. In summary, our study illustrates how a multi-model system approach paves the way for the discovery and molecular delineation of gene regulatory networks controlling atrial rhythm with application to AF.
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Affiliation(s)
- Anaïs Kervadec
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - James Kezos
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Haibo Ni
- Department of Pharmacology, UC Davis, Davis, CA 95616, USA
| | - Michael Yu
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - James Marchant
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Sean Spiering
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Suraj Kannan
- Johns Hopkins University, Baltimore, MD 21205, USA
| | - Chulan Kwon
- Johns Hopkins University, Baltimore, MD 21205, USA
| | | | - Rolf Bodmer
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | | | - Karen Ocorr
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Alexandre R. Colas
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
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15
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Bowman AJ, Huang C, Schnitzer MJ, Kasevich MA. Wide-field fluorescence lifetime imaging of neuron spiking and subthreshold activity in vivo. Science 2023; 380:1270-1275. [PMID: 37347862 PMCID: PMC10361454 DOI: 10.1126/science.adf9725] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 05/16/2023] [Indexed: 06/24/2023]
Abstract
The development of voltage-sensitive fluorescent probes suggests fluorescence lifetime as a promising readout for electrical activity in biological systems. Existing approaches fail to achieve the speed and sensitivity required for voltage imaging in neuroscience applications. We demonstrated that wide-field electro-optic fluorescence lifetime imaging microscopy (EO-FLIM) allows lifetime imaging at kilohertz frame-acquisition rates, spatially resolving action potential propagation and subthreshold neural activity in live adult Drosophila. Lifetime resolutions of <5 picoseconds at 1 kilohertz were achieved for single-cell voltage recordings. Lifetime readout is limited by photon shot noise, and the method provides strong rejection of motion artifacts and technical noise sources. Recordings revealed local transmembrane depolarizations, two types of spikes with distinct fluorescence lifetimes, and phase locking of spikes to an external mechanical stimulus.
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Affiliation(s)
- Adam J. Bowman
- Physics Department, Stanford University; 382 Via Pueblo Mall, Stanford, California 94305, USA
| | - Cheng Huang
- James H. Clark Center, Stanford University; 318 Campus Dr., Stanford, CA 94305, USA
- Present Address: Department of Neuroscience, Washington University School of Medicine St. Louis, MO 63110, USA
| | - Mark J. Schnitzer
- James H. Clark Center, Stanford University; 318 Campus Dr., Stanford, CA 94305, USA
- CNC Program, Stanford University; Stanford, CA, USA
- Howard Hughes Medical Institute, Stanford University; Stanford, CA, USA
| | - Mark A. Kasevich
- Physics Department, Stanford University; 382 Via Pueblo Mall, Stanford, California 94305, USA
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16
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Nikolaev DM, Mironov VN, Shtyrov AA, Kvashnin ID, Mereshchenko AS, Vasin AV, Panov MS, Ryazantsev MN. Fluorescence Imaging of Cell Membrane Potential: From Relative Changes to Absolute Values. Int J Mol Sci 2023; 24:ijms24032435. [PMID: 36768759 PMCID: PMC9916766 DOI: 10.3390/ijms24032435] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 01/20/2023] [Accepted: 01/23/2023] [Indexed: 01/28/2023] Open
Abstract
Membrane potential is a fundamental property of biological cells. Changes in membrane potential characterize a vast number of vital biological processes, such as the activity of neurons and cardiomyocytes, tumorogenesis, cell-cycle progression, etc. A common strategy to record membrane potential changes that occur in the process of interest is to utilize organic dyes or genetically-encoded voltage indicators with voltage-dependent fluorescence. Sensors are introduced into target cells, and alterations of fluorescence intensity are recorded with optical methods. Techniques that allow recording relative changes of membrane potential and do not take into account fluorescence alterations due to factors other than membrane voltage are already widely used in modern biological and biomedical studies. Such techniques have been reviewed previously in many works. However, in order to investigate a number of processes, especially long-term processes, the measured signal must be corrected to exclude the contribution from voltage-independent factors or even absolute values of cell membrane potential have to be evaluated. Techniques that enable such measurements are the subject of this review.
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Affiliation(s)
- Dmitrii M. Nikolaev
- Institute of Biomedical Systems and Biotechnologies, Peter the Great Saint Petersburg Polytechnic University, 29 Polytechnicheskaya str., 195251 Saint Petersburg, Russia
- Nanotechnology Research and Education Centre RAS, Saint Petersburg Academic University, 8/3 Khlopina str., 194021 Saint Petersburg, Russia
| | - Vladimir N. Mironov
- Nanotechnology Research and Education Centre RAS, Saint Petersburg Academic University, 8/3 Khlopina str., 194021 Saint Petersburg, Russia
| | - Andrey A. Shtyrov
- Institute of Biomedical Systems and Biotechnologies, Peter the Great Saint Petersburg Polytechnic University, 29 Polytechnicheskaya str., 195251 Saint Petersburg, Russia
- Nanotechnology Research and Education Centre RAS, Saint Petersburg Academic University, 8/3 Khlopina str., 194021 Saint Petersburg, Russia
| | - Iaroslav D. Kvashnin
- Nanotechnology Research and Education Centre RAS, Saint Petersburg Academic University, 8/3 Khlopina str., 194021 Saint Petersburg, Russia
| | - Andrey S. Mereshchenko
- Institute of Chemistry, Saint Petersburg State University, 26 Universitetskii pr, 198504 Saint Petersburg, Russia
| | - Andrey V. Vasin
- Institute of Biomedical Systems and Biotechnologies, Peter the Great Saint Petersburg Polytechnic University, 29 Polytechnicheskaya str., 195251 Saint Petersburg, Russia
| | - Maxim S. Panov
- Institute of Chemistry, Saint Petersburg State University, 26 Universitetskii pr, 198504 Saint Petersburg, Russia
- Center for Biophysical Studies, Saint Petersburg State Chemical Pharmaceutical University, 14 Professor Popov str., lit. A, 197022 Saint Petersburg, Russia
| | - Mikhail N. Ryazantsev
- Nanotechnology Research and Education Centre RAS, Saint Petersburg Academic University, 8/3 Khlopina str., 194021 Saint Petersburg, Russia
- Institute of Chemistry, Saint Petersburg State University, 26 Universitetskii pr, 198504 Saint Petersburg, Russia
- Correspondence:
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17
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Abstract
Biomembranes are ubiquitous lipid structures that delimit the cell surface and organelles and operate as platforms for a multitude of biomolecular processes. The development of chemical tools─fluorescent probes─for the sensing and imaging of biomembranes is a rapidly growing research direction, stimulated by a high demand from cell biologists and biophysicists. This Account focuses on advances in these smart molecules, providing a voyage from the cell frontier─plasma membranes (PM)─toward intracellular membrane compartments─organelles. General classification of the membrane probes can be based on targeting principles, sensing profile, and optical response. Probes for PM and organelle membranes are designed based on multiple targeting principles: conjugation with natural lipids or synthetic targeting ligands and in situ cell labeling by bio-orthogonal chemistry, conjugation to protein tags, and receptor-ligand interactions. Thus, to obtain membrane probes targeting PM with selectivity to one leaflet, we designed membrane anchor ligands based on a charged group and an alkyl chain. According to the sensing profile, we define basic membrane markers with constant emission and probes for biophysical and chemical sensing. The markers are built from classical fluorophores, exemplified by a series of bright cyanines and BODIPY dyes bearing the PM anchors (MemBright). Membrane probes for biophysical sensing are based on environment-sensitive fluorophores: (1) polarity-sensitive solvatochromic dyes; (2) viscosity-sensitive fluorescent molecular rotors; (3) mechanosensitive fluorescent flippers; and (4) voltage-sensitive electrochromic dyes. Our solvatochromic probes based on Nile Red (NR12S, NR12A, NR4A), Laurdan (Pro12A), and 3-hydroxyflavone (F2N12S) through polarity-sensing can visualize liquid ordered and disordered phases of lipid membranes, sense lipid order and its heterogeneity in cell PM, detect apoptosis, etc. Chemically sensitive probes, combining a dye, membrane-targeting ligand, and molecular recognition unit, enable the detection of pH, ions, redox species, lipids, and proteins at the biomembrane surface. In terms of the optical response profile, we can identify (1) fluorogenic (turn-on) probes, allowing background-free imaging; (2) ratiometric probes, e.g., solvatochromic probes, which enable ratiometric imaging by changing their emission/excitation color; (3) fluorescence lifetime-responsive probes, e.g., fluorescence molecular rotors and flippers, suitable for fluorescence lifetime imaging (FLIM); and (4) switchable probes, important for single-molecule localization microscopy. We showed that combining solvatochromic probes with on-off switching through a reversible binding specifically to cell PM enables the mapping of their biophysical properties with superior resolution. While the majority of efforts have been focused on PM, the probes for cellular organelles, such as endoplasmic reticulum, mitochondria, Golgi apparatus, etc., emerge rapidly. Thus, nontargeted solvatochromic probes can distinguish organelles by the emission color. Targeted solvatochromic probes based on Nile Red revealed unique signatures of polarity and lipid order of individual organelles and their different sensitivities to oxidative or mechanical stress. Lipid droplets, which are membraneless lipidic structures, constitute another interesting organelle target for probing the cell stress. Currently, we stand at the beginning of a long route with big challenges ahead, in particular (1) to achieve superior organelle specificity; (2) to label specific biomembrane leaflets, notably the inner leaflet of PM; (3) to detect lipid organization in a proximity of specific proteins; and (4) to probe biomembranes in tissues and animals.
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Affiliation(s)
- Andrey S Klymchenko
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, 67401 Illkirch, France
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18
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Yao C, de Silva AP. A Tool, an App and a Field: Fluorescent PET Sensors, Blood Electrolyte Analysis and Molecular Logic as Products of Supramolecular Photoscience from Northern Ireland and Sri Lanka. Chempluschem 2022; 88:e202200362. [PMID: 36456470 DOI: 10.1002/cplu.202200362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 11/22/2022] [Indexed: 12/05/2022]
Abstract
The general tool of fluorescent PET (photoinduced electron transfer) sensors/switches - a molecular design principle with engineering features - is outlined, with the aid of frontier orbital energy diagrams. Fluorophores such as anthracene, 1,3-diaryl-Δ2 -pyrazolines and 4-amino-1,8-naphthalimides are employed within this system, alongside receptors such as amines, carboxylates, crown ethers and amino acids. This tool appealed to a multinational corporation for building a medical analyzer for electrolytes such as Na+ , K+ , Ca2+ and gases like CO2 , which became a commercially successful application. Finally, the tool was a springboard for chemistry to cross into computer science. The field of molecular logic can elucidate how molecules inside us handle information. Molecular examples of the simplest logic gates such as YES, NOT, OR, AND are described. A case of a human-level computation - visual edge detection - is also included.
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Affiliation(s)
- Chao‐Yi Yao
- School of Chemistry and Chemical Engineering Queen's University Belfast BT9 5AG Northern Ireland
| | - A. Prasanna de Silva
- School of Chemistry and Chemical Engineering Queen's University Belfast BT9 5AG Northern Ireland
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19
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Yang Y, Liu A, Tsai CT, Liu C, Wu JC, Cui B. Cardiotoxicity drug screening based on whole-panel intracellular recording. Biosens Bioelectron 2022; 216:114617. [PMID: 36027802 PMCID: PMC9930661 DOI: 10.1016/j.bios.2022.114617] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 07/18/2022] [Accepted: 07/31/2022] [Indexed: 01/11/2023]
Abstract
Unintended binding of small-molecule drugs to ion channels affects electrophysiological properties of cardiomyocytes and potentially leads to arrhythmia and heart failure. The waveforms of intracellular action potentials reflect the coordinated activities of cardiac ion channels and serve as a reliable means for assessing drug toxicity, but the implementation is limited by the low throughput of patch clamp for intracellular recording measurements. In the last decade, several new technologies are being developed to address this challenge. We recently developed the nanocrown electrode array (NcEA) technology that allows robust, parallel, and long-duration recording of intracellular action potentials (iAPs). Here, we demonstrate that NcEAs allow comparison of iAP waveforms before and after drug treatment from the same cell. This self-referencing comparison not only shows distinct drug effects of sodium, potassium, and calcium blockers, but also reveals subtle differences among three subclasses of sodium channel blockers with sub-millisecond accuracy. Furthermore, self-referencing comparison unveils heterogeneous drug responses among different cells. In our study, whole-panel simultaneous intracellular recording can be reliably achieved with ∼94% success rate. The average duration of intracellular recording is ∼30 min and some last longer than 2 h. With its high reliability, long recording duration, and easy-to-use nature, NcEA would be useful for iAP-based preclinical drug screening.
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Affiliation(s)
- Yang Yang
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
| | - Aofei Liu
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
| | - Ching-Ting Tsai
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
| | - Chun Liu
- Stanford Cardiovascular Institute, Stanford University, Stanford, CA, USA
| | - Joseph C. Wu
- Stanford Cardiovascular Institute, Stanford University, Stanford, CA, USA,Department of Medicine, Stanford University, Stanford, CA, USA,Department of Radiology, Stanford University, Stanford, CA, USA
| | - Bianxiao Cui
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA; Wu-Tsai Neuroscience Institute, Stanford University, Stanford, CA, USA.
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20
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Zhou X, Fang Y, Wimalasiri V, Stains CI, Miller EW. A long-wavelength xanthene dye for photoacoustic imaging. Chem Commun (Camb) 2022; 58:11941-11944. [PMID: 36196957 PMCID: PMC9634815 DOI: 10.1039/d2cc03947h] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2023]
Abstract
Photoacoustic (PA) imaging is a powerful biomedical imaging modality. We designed KeTMR and KeJuR, two xanthene-based dyes that were readily obtained through a 2-step synthetic route. KeJuR has low molecular weight, good aqueous solubility, and superior chemical stability compared to KeTMR. KeJuR shows a robust PA signal under 860 nm excitation and can be paired with traditional PA dyes for multiplex imaging in blood samples under a tissue-mimicking environment.
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Affiliation(s)
- Xinqi Zhou
- Department of Chemistry, University of California, Berkeley, CA, 94720, USA.
| | - Yuan Fang
- Department of Chemistry, University of Virginia, Charlottesville, VA, 22904, USA
| | - Viranga Wimalasiri
- Department of Chemistry, University of Virginia, Charlottesville, VA, 22904, USA
| | - Cliff I Stains
- Department of Chemistry, University of Virginia, Charlottesville, VA, 22904, USA
- University of Virgnia Cancer Center, University of Virginia, Charlottesville, VA, 22904, USA
| | - Evan W Miller
- Department of Chemistry, University of California, Berkeley, CA, 94720, USA.
- Department of Molecular & Cell Biology, University of California, Berkeley, CA, 94720, USA
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA, 94720, USA
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21
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Al Abed A, Wei Y, Almasri RM, Lei X, Wang H, Firth J, Chen Y, Gouailhardou N, Silvestri L, Lehmann T, Ladouceur F, Lovell NH. Liquid crystal electro-optical transducers for electrophysiology sensing applications. J Neural Eng 2022; 19. [DOI: 10.1088/1741-2552/ac8ed6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 09/01/2022] [Indexed: 11/06/2022]
Abstract
Abstract
Objective. Biomedical instrumentation and clinical systems for electrophysiology rely on electrodes and wires for sensing and transmission of bioelectric signals. However, this electronic approach constrains bandwidth, signal conditioning circuit designs, and the number of channels in invasive or miniature devices. This paper demonstrates an alternative approach using light to sense and transmit the electrophysiological signals. Approach. We develop a sensing, passive, fluorophore-free optrode based on the birefringence property of liquid crystals (LCs) operating at the microscale. Main results. We show that these optrodes can have the appropriate linearity (µ ± s.d.: 99.4 ± 0.5%, n = 11 devices), relative responsivity (µ ± s.d.: 57 ± 12%V−1, n = 5 devices), and bandwidth (µ ± s.d.: 11.1 ± 0.7 kHz, n = 7 devices) for transducing electrophysiology signals into the optical domain. We report capture of rabbit cardiac sinoatrial electrograms and stimulus-evoked compound action potentials from the rabbit sciatic nerve. We also demonstrate miniaturisation potential by fabricating multi-optrode arrays, by developing a process that automatically matches each transducer element area with that of its corresponding biological interface. Significance. Our method of employing LCs to convert bioelectric signals into the optical domain will pave the way for the deployment of high-bandwidth optical telecommunications techniques in ultra-miniature clinical diagnostic and research laboratory neural and cardiac interfaces.
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22
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McCann JT, Benlian BR, Yaeger-Weiss SK, Knudson IJ, He M, Miller EW. Flipping the Switch: Reverse-Demand Voltage-Sensitive Fluorophores. J Am Chem Soc 2022; 144:13050-13054. [PMID: 35834763 PMCID: PMC9462387 DOI: 10.1021/jacs.2c05385] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Fluorescence microscopy with fluorescent reporters that respond to environmental cues is a powerful method for interrogating biochemistry and biophysics in living systems. Photoinduced electron transfer (PeT) is commonly used as a trigger to modulate fluorescence in response to changes in the biological environment. PeT-based indicators rely on PeT either into the excited state (acceptor PeT) or out of the excited state (donor PeT). Our group has been developing voltage-sensitive fluorophores (VF dyes) that respond to changes in biological membrane potential (Vm). We hypothesize that the mechanism of voltage sensitivity arises from acceptor PeT (a-PeT) from an electron-rich aniline-containing molecular wire into the excited-state fluorophore, resulting in decreased fluorescence at negative Vm. In this work, we reversed the direction of electron flow to access donor-excited PeT (d-PeT) VF dyes by introducing electron-withdrawing rather than electron-rich molecular wires. VF dyes containing electron-withdrawing groups show voltage-sensitive fluorescence, but with the opposite polarity: hyperpolarizing Vm now gives fluorescence increases. We used a combination of computation and experiment to design and synthesize five d-PeT VF targets, two of which are voltage-sensitive.
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23
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Dutta T, Pal K, Koner AL. Intracellular Physical Properties with Small Organic Fluorescent Probes: Recent Advances and Future Perspectives. CHEM REC 2022; 22:e202200035. [PMID: 35801859 DOI: 10.1002/tcr.202200035] [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: 02/21/2022] [Revised: 06/22/2022] [Indexed: 11/09/2022]
Abstract
The intracellular physical parameters i. e., polarity, viscosity, fluidity, tension, potential, and temperature of a live cell are the hallmark of cellular health and have garnered immense interest over the past decade. In this context, small molecule organic fluorophores exhibit prominent useful properties including easy functionalizability, environmental sensitivity, biocompatibility, and fast yet efficient cellular uptakability which has made them a popular tool to understand intra-cellular micro-environmental properties. Throughout this discussion, we have outlined the basic design strategies of small molecules for specific organelle targeting and quantification of physical properties. The values of these parameters are indicative of cellular homeostasis and subtle alteration may be considered as the onset of disease. We believe this comprehensive review will facilitate the development of potential future probes for superior insight into the physical parameters that are yet to be quantified.
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Affiliation(s)
- Tanoy Dutta
- Bionanotechnology Laboratory, Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, Madhya Pradesh, 462066, INDIA (TD) (ALK
| | - Kaushik Pal
- Bionanotechnology Laboratory, Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, Madhya Pradesh, 462066, INDIA (TD) (ALK.,Department of Physics and Astronomy, Iowa State University, Ames, Iowa, 50011, USA
| | - Apurba Lal Koner
- Bionanotechnology Laboratory, Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, Madhya Pradesh, 462066, INDIA (TD) (ALK
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24
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Khadria A. Tools to measure membrane potential of neurons. Biomed J 2022; 45:749-762. [DOI: 10.1016/j.bj.2022.05.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 05/08/2022] [Accepted: 05/29/2022] [Indexed: 12/31/2022] Open
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25
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Verdes M, Mace K, Margetts L, Cartmell S. Status and challenges of electrical stimulation use in chronic wound healing. Curr Opin Biotechnol 2022; 75:102710. [DOI: 10.1016/j.copbio.2022.102710] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 11/19/2021] [Accepted: 03/07/2022] [Indexed: 12/12/2022]
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Fiala T, Mosharov EV, Wang J, Mendieta AM, Choi SJ, Fialova E, Hwu C, Sulzer D, Sames D. Chemical Targeting of Rhodol Voltage-Sensitive Dyes to Dopaminergic Neurons. ACS Chem Neurosci 2022; 13:1251-1262. [PMID: 35400149 DOI: 10.1021/acschemneuro.1c00862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Optical imaging of changes in the membrane potential of living cells can be achieved by means of fluorescent voltage-sensitive dyes (VSDs). A particularly challenging task is to efficiently deliver these highly lipophilic probes to specific neuronal subpopulations in brain tissue. We have tackled this task by designing a solubilizing, hydrophilic polymer platform that carries a high-affinity ligand for a membrane protein marker of interest and a fluorescent VSD. Here, we disclose an improved design of polymer-supported probes for chemical, nongenetic targeting of voltage sensors to axons natively expressing the dopamine transporter in ex vivo mouse brain tissue. We first show that for negatively charged rhodol VSDs functioning on the photoinduced electron transfer principle, poly(ethylene glycol) as a carrier enables targeting with higher selectivity than the polysaccharide dextran in HEK cell culture. In the same experimental setting, we also demonstrate that incorporation of an azetidine ring into the rhodol chromophore substantially increases the brightness and voltage sensitivity of the respective VSD. We show that the superior properties of the optimized sensor are transferable to recording of electrically evoked activity from dopaminergic axons in mouse striatal slices after averaging of multiple trials. Finally, we suggest the next milestones for the field to achieve single-scan recordings with nongenetically targeted VSDs in native brain tissue.
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Affiliation(s)
- Tomas Fiala
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Eugene V. Mosharov
- Department of Neurology, Columbia University Irving Medical Center, New York, New York 10032, United States
| | - Jihang Wang
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Adriana M. Mendieta
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Se Joon Choi
- Department of Psychiatry, Columbia University Irving Medical Center, New York, New York 10032, United States
| | - Eva Fialova
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Christopher Hwu
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - David Sulzer
- Department of Neurology, Columbia University Irving Medical Center, New York, New York 10032, United States
- Department of Psychiatry, Columbia University Irving Medical Center, New York, New York 10032, United States
- Department of Pharmacology, Columbia University Irving Medical Center, New York, New York 10032, United States
- Department of Molecular Therapeutics, New York State Psychiatric Institute, New York, New York 10032, United States
| | - Dalibor Sames
- Department of Chemistry, Columbia University, New York, New York 10027, United States
- NeuroTechnology Center at Columbia University, New York, New York 10027, United States
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Behavioral Neuroscience in the Era of Genomics: Tools and Lessons for Analyzing High-Dimensional Datasets. Int J Mol Sci 2022; 23:ijms23073811. [PMID: 35409169 PMCID: PMC8998543 DOI: 10.3390/ijms23073811] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/26/2022] [Accepted: 03/29/2022] [Indexed: 12/10/2022] Open
Abstract
Behavioral neuroscience underwent a technology-driven revolution with the emergence of machine-vision and machine-learning technologies. These technological advances facilitated the generation of high-resolution, high-throughput capture and analysis of complex behaviors. Therefore, behavioral neuroscience is becoming a data-rich field. While behavioral researchers use advanced computational tools to analyze the resulting datasets, the search for robust and standardized analysis tools is still ongoing. At the same time, the field of genomics exploded with a plethora of technologies which enabled the generation of massive datasets. This growth of genomics data drove the emergence of powerful computational approaches to analyze these data. Here, we discuss the composition of a large behavioral dataset, and the differences and similarities between behavioral and genomics data. We then give examples of genomics-related tools that might be of use for behavioral analysis and discuss concepts that might emerge when considering the two fields together.
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Grenier V, Martinez KN, Benlian BR, García-Almedina DM, Raliski BK, Boggess SC, Maza JC, Yang SJ, Gest AMM, Miller EW. Molecular Prosthetics for Long-Term Functional Imaging with Fluorescent Reporters. ACS CENTRAL SCIENCE 2022; 8:118-121. [PMID: 35111902 PMCID: PMC8802189 DOI: 10.1021/acscentsci.1c01153] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Indexed: 06/14/2023]
Abstract
Voltage-sensitive fluorescent reporters can reveal fast changes in the membrane potential in neurons and cardiomyocytes. However, in many cases, illumination in the presence of the fluorescent reporters results in disruptions to the action potential shape that limits the length of recording sessions. We show here that a molecular prosthetic approach, previously limited to fluorophores, rather than indicators, can be used to substantially prolong imaging in neurons and cardiomyocytes.
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Affiliation(s)
- Vincent Grenier
- Department
of Chemistry and Department of Molecular and Cell Biology and Helen Wills Neuroscience
Institute. University of California, Berkeley, California 94720, United States
| | - Kayli N. Martinez
- Department
of Chemistry and Department of Molecular and Cell Biology and Helen Wills Neuroscience
Institute. University of California, Berkeley, California 94720, United States
| | - Brittany R. Benlian
- Department
of Chemistry and Department of Molecular and Cell Biology and Helen Wills Neuroscience
Institute. University of California, Berkeley, California 94720, United States
| | - Derek M. García-Almedina
- Department
of Chemistry and Department of Molecular and Cell Biology and Helen Wills Neuroscience
Institute. University of California, Berkeley, California 94720, United States
| | - Benjamin K. Raliski
- Department
of Chemistry and Department of Molecular and Cell Biology and Helen Wills Neuroscience
Institute. University of California, Berkeley, California 94720, United States
| | - Steven C. Boggess
- Department
of Chemistry and Department of Molecular and Cell Biology and Helen Wills Neuroscience
Institute. University of California, Berkeley, California 94720, United States
| | - Johnathan C. Maza
- Department
of Chemistry and Department of Molecular and Cell Biology and Helen Wills Neuroscience
Institute. University of California, Berkeley, California 94720, United States
| | - Samantha J. Yang
- Department
of Chemistry and Department of Molecular and Cell Biology and Helen Wills Neuroscience
Institute. University of California, Berkeley, California 94720, United States
| | - Anneliese M. M. Gest
- Department
of Chemistry and Department of Molecular and Cell Biology and Helen Wills Neuroscience
Institute. University of California, Berkeley, California 94720, United States
| | - Evan W. Miller
- Department
of Chemistry and Department of Molecular and Cell Biology and Helen Wills Neuroscience
Institute. University of California, Berkeley, California 94720, United States
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30
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Abdelfattah AS, Ahuja S, Akkin T, Allu SR, Brake J, Boas DA, Buckley EM, Campbell RE, Chen AI, Cheng X, Čižmár T, Costantini I, De Vittorio M, Devor A, Doran PR, El Khatib M, Emiliani V, Fomin-Thunemann N, Fainman Y, Fernandez-Alfonso T, Ferri CGL, Gilad A, Han X, Harris A, Hillman EMC, Hochgeschwender U, Holt MG, Ji N, Kılıç K, Lake EMR, Li L, Li T, Mächler P, Miller EW, Mesquita RC, Nadella KMNS, Nägerl UV, Nasu Y, Nimmerjahn A, Ondráčková P, Pavone FS, Perez Campos C, Peterka DS, Pisano F, Pisanello F, Puppo F, Sabatini BL, Sadegh S, Sakadzic S, Shoham S, Shroff SN, Silver RA, Sims RR, Smith SL, Srinivasan VJ, Thunemann M, Tian L, Tian L, Troxler T, Valera A, Vaziri A, Vinogradov SA, Vitale F, Wang LV, Uhlířová H, Xu C, Yang C, Yang MH, Yellen G, Yizhar O, Zhao Y. Neurophotonic tools for microscopic measurements and manipulation: status report. NEUROPHOTONICS 2022; 9:013001. [PMID: 35493335 PMCID: PMC9047450 DOI: 10.1117/1.nph.9.s1.013001] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Neurophotonics was launched in 2014 coinciding with the launch of the BRAIN Initiative focused on development of technologies for advancement of neuroscience. For the last seven years, Neurophotonics' agenda has been well aligned with this focus on neurotechnologies featuring new optical methods and tools applicable to brain studies. While the BRAIN Initiative 2.0 is pivoting towards applications of these novel tools in the quest to understand the brain, this status report reviews an extensive and diverse toolkit of novel methods to explore brain function that have emerged from the BRAIN Initiative and related large-scale efforts for measurement and manipulation of brain structure and function. Here, we focus on neurophotonic tools mostly applicable to animal studies. A companion report, scheduled to appear later this year, will cover diffuse optical imaging methods applicable to noninvasive human studies. For each domain, we outline the current state-of-the-art of the respective technologies, identify the areas where innovation is needed, and provide an outlook for the future directions.
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Affiliation(s)
- Ahmed S. Abdelfattah
- Brown University, Department of Neuroscience, Providence, Rhode Island, United States
| | - Sapna Ahuja
- University of Pennsylvania, Perelman School of Medicine, Department of Biochemistry and Biophysics, Philadelphia, Pennsylvania, United States
- University of Pennsylvania, School of Arts and Sciences, Department of Chemistry, Philadelphia, Pennsylvania, United States
| | - Taner Akkin
- University of Minnesota, Department of Biomedical Engineering, Minneapolis, Minnesota, United States
| | - Srinivasa Rao Allu
- University of Pennsylvania, Perelman School of Medicine, Department of Biochemistry and Biophysics, Philadelphia, Pennsylvania, United States
- University of Pennsylvania, School of Arts and Sciences, Department of Chemistry, Philadelphia, Pennsylvania, United States
| | - Joshua Brake
- Harvey Mudd College, Department of Engineering, Claremont, California, United States
| | - David A. Boas
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Erin M. Buckley
- Georgia Institute of Technology and Emory University, Wallace H. Coulter Department of Biomedical Engineering, Atlanta, Georgia, United States
- Emory University, Department of Pediatrics, Atlanta, Georgia, United States
| | - Robert E. Campbell
- University of Tokyo, Department of Chemistry, Tokyo, Japan
- University of Alberta, Department of Chemistry, Edmonton, Alberta, Canada
| | - Anderson I. Chen
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Xiaojun Cheng
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Tomáš Čižmár
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Irene Costantini
- University of Florence, European Laboratory for Non-Linear Spectroscopy, Department of Biology, Florence, Italy
- National Institute of Optics, National Research Council, Rome, Italy
| | - Massimo De Vittorio
- Istituto Italiano di Tecnologia, Center for Biomolecular Nanotechnologies, Arnesano, Italy
| | - Anna Devor
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts, United States
| | - Patrick R. Doran
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Mirna El Khatib
- University of Pennsylvania, Perelman School of Medicine, Department of Biochemistry and Biophysics, Philadelphia, Pennsylvania, United States
- University of Pennsylvania, School of Arts and Sciences, Department of Chemistry, Philadelphia, Pennsylvania, United States
| | | | - Natalie Fomin-Thunemann
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Yeshaiahu Fainman
- University of California San Diego, Department of Electrical and Computer Engineering, La Jolla, California, United States
| | - Tomas Fernandez-Alfonso
- University College London, Department of Neuroscience, Physiology and Pharmacology, London, United Kingdom
| | - Christopher G. L. Ferri
- University of California San Diego, Departments of Neurosciences, La Jolla, California, United States
| | - Ariel Gilad
- The Hebrew University of Jerusalem, Institute for Medical Research Israel–Canada, Department of Medical Neurobiology, Faculty of Medicine, Jerusalem, Israel
| | - Xue Han
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Andrew Harris
- Weizmann Institute of Science, Department of Brain Sciences, Rehovot, Israel
| | | | - Ute Hochgeschwender
- Central Michigan University, Department of Neuroscience, Mount Pleasant, Michigan, United States
| | - Matthew G. Holt
- University of Porto, Instituto de Investigação e Inovação em Saúde (i3S), Porto, Portugal
| | - Na Ji
- University of California Berkeley, Department of Physics, Berkeley, California, United States
| | - Kıvılcım Kılıç
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Evelyn M. R. Lake
- Yale School of Medicine, Department of Radiology and Biomedical Imaging, New Haven, Connecticut, United States
| | - Lei Li
- California Institute of Technology, Andrew and Peggy Cherng Department of Medical Engineering, Department of Electrical Engineering, Pasadena, California, United States
| | - Tianqi Li
- University of Minnesota, Department of Biomedical Engineering, Minneapolis, Minnesota, United States
| | - Philipp Mächler
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Evan W. Miller
- University of California Berkeley, Departments of Chemistry and Molecular & Cell Biology and Helen Wills Neuroscience Institute, Berkeley, California, United States
| | | | | | - U. Valentin Nägerl
- Interdisciplinary Institute for Neuroscience University of Bordeaux & CNRS, Bordeaux, France
| | - Yusuke Nasu
- University of Tokyo, Department of Chemistry, Tokyo, Japan
| | - Axel Nimmerjahn
- Salk Institute for Biological Studies, Waitt Advanced Biophotonics Center, La Jolla, California, United States
| | - Petra Ondráčková
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Francesco S. Pavone
- National Institute of Optics, National Research Council, Rome, Italy
- University of Florence, European Laboratory for Non-Linear Spectroscopy, Department of Physics, Florence, Italy
| | - Citlali Perez Campos
- Columbia University, Zuckerman Mind Brain Behavior Institute, New York, United States
| | - Darcy S. Peterka
- Columbia University, Zuckerman Mind Brain Behavior Institute, New York, United States
| | - Filippo Pisano
- Istituto Italiano di Tecnologia, Center for Biomolecular Nanotechnologies, Arnesano, Italy
| | - Ferruccio Pisanello
- Istituto Italiano di Tecnologia, Center for Biomolecular Nanotechnologies, Arnesano, Italy
| | - Francesca Puppo
- University of California San Diego, Departments of Neurosciences, La Jolla, California, United States
| | - Bernardo L. Sabatini
- Harvard Medical School, Howard Hughes Medical Institute, Department of Neurobiology, Boston, Massachusetts, United States
| | - Sanaz Sadegh
- University of California San Diego, Departments of Neurosciences, La Jolla, California, United States
| | - Sava Sakadzic
- Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts, United States
| | - Shy Shoham
- New York University Grossman School of Medicine, Tech4Health and Neuroscience Institutes, New York, New York, United States
| | - Sanaya N. Shroff
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - R. Angus Silver
- University College London, Department of Neuroscience, Physiology and Pharmacology, London, United Kingdom
| | - Ruth R. Sims
- Sorbonne University, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Spencer L. Smith
- University of California Santa Barbara, Department of Electrical and Computer Engineering, Santa Barbara, California, United States
| | - Vivek J. Srinivasan
- New York University Langone Health, Departments of Ophthalmology and Radiology, New York, New York, United States
| | - Martin Thunemann
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Lei Tian
- Boston University, Departments of Electrical Engineering and Biomedical Engineering, Boston, Massachusetts, United States
| | - Lin Tian
- University of California Davis, Department of Biochemistry and Molecular Medicine, Davis, California, United States
| | - Thomas Troxler
- University of Pennsylvania, Perelman School of Medicine, Department of Biochemistry and Biophysics, Philadelphia, Pennsylvania, United States
- University of Pennsylvania, School of Arts and Sciences, Department of Chemistry, Philadelphia, Pennsylvania, United States
| | - Antoine Valera
- University College London, Department of Neuroscience, Physiology and Pharmacology, London, United Kingdom
| | - Alipasha Vaziri
- Rockefeller University, Laboratory of Neurotechnology and Biophysics, New York, New York, United States
- The Rockefeller University, The Kavli Neural Systems Institute, New York, New York, United States
| | - Sergei A. Vinogradov
- University of Pennsylvania, Perelman School of Medicine, Department of Biochemistry and Biophysics, Philadelphia, Pennsylvania, United States
- University of Pennsylvania, School of Arts and Sciences, Department of Chemistry, Philadelphia, Pennsylvania, United States
| | - Flavia Vitale
- Center for Neuroengineering and Therapeutics, Departments of Neurology, Bioengineering, Physical Medicine and Rehabilitation, Philadelphia, Pennsylvania, United States
| | - Lihong V. Wang
- California Institute of Technology, Andrew and Peggy Cherng Department of Medical Engineering, Department of Electrical Engineering, Pasadena, California, United States
| | - Hana Uhlířová
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Chris Xu
- Cornell University, School of Applied and Engineering Physics, Ithaca, New York, United States
| | - Changhuei Yang
- California Institute of Technology, Departments of Electrical Engineering, Bioengineering and Medical Engineering, Pasadena, California, United States
| | - Mu-Han Yang
- University of California San Diego, Department of Electrical and Computer Engineering, La Jolla, California, United States
| | - Gary Yellen
- Harvard Medical School, Department of Neurobiology, Boston, Massachusetts, United States
| | - Ofer Yizhar
- Weizmann Institute of Science, Department of Brain Sciences, Rehovot, Israel
| | - Yongxin Zhao
- Carnegie Mellon University, Department of Biological Sciences, Pittsburgh, Pennsylvania, United States
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31
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Heynck L, Matthias J, Bossi ML, Butkevich AN, Hell SW. N-Cyanorhodamines: cell-permeant, photostable and bathochromically shifted analogues of fluoresceins. Chem Sci 2022; 13:8297-8306. [PMID: 35919709 PMCID: PMC9297387 DOI: 10.1039/d2sc02448a] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 06/24/2022] [Indexed: 11/23/2022] Open
Abstract
Fluorescein and its analogues have found only limited use in biological imaging because of the poor photostability and cell membrane impermeability of their O-unprotected forms. Herein, we report rationally designed N-cyanorhodamines as orange- to red-emitting, photostable and cell-permeant fluorescent labels negatively charged at physiological pH values and thus devoid of off-targeting artifacts often observed for cationic fluorophores. In combination with well-established fluorescent labels, self-labelling protein (HaloTag, SNAP-tag) ligands derived from N-cyanorhodamines permit up to four-colour confocal and super-resolution STED imaging in living cells. N-Cyanorhodamines – photostable, cell-permeant analogues of fluoresceins – provide fast labelling kinetics with the HaloTag protein and background-free images in multicolour super-resolution microscopy.![]()
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Affiliation(s)
- Lukas Heynck
- Department of Optical Nanoscopy, Max Planck Institute for Medical Research, 69120 Heidelberg, Germany
| | - Jessica Matthias
- Department of Optical Nanoscopy, Max Planck Institute for Medical Research, 69120 Heidelberg, Germany
| | - Mariano L. Bossi
- Department of NanoBiophotonics, Max Planck Institute for Multidisciplinary Sciences, 37077 Göttingen, Germany
| | - Alexey N. Butkevich
- Department of Optical Nanoscopy, Max Planck Institute for Medical Research, 69120 Heidelberg, Germany
- Department of NanoBiophotonics, Max Planck Institute for Multidisciplinary Sciences, 37077 Göttingen, Germany
| | - Stefan W. Hell
- Department of Optical Nanoscopy, Max Planck Institute for Medical Research, 69120 Heidelberg, Germany
- Department of NanoBiophotonics, Max Planck Institute for Multidisciplinary Sciences, 37077 Göttingen, Germany
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32
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Belen’kii LI, Gazieva GA, Evdokimenkova YB, Soboleva NO. The literature of heterocyclic chemistry, Part XX, 2020. ADVANCES IN HETEROCYCLIC CHEMISTRY 2022. [DOI: 10.1016/bs.aihch.2022.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
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33
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Ortiz G, Liu P, Deal PE, Nensel AK, Martinez KN, Shamardani K, Adesnik H, Miller EW. A silicon-rhodamine chemical-genetic hybrid for far red voltage imaging from defined neurons in brain slice. RSC Chem Biol 2021; 2:1594-1599. [PMID: 34977574 PMCID: PMC8637932 DOI: 10.1039/d1cb00156f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 09/27/2021] [Indexed: 02/06/2023] Open
Abstract
We describe the design, synthesis, and application of voltage-sensitive silicon rhodamines. Based on the Berkeley Red Sensor of Transmembrane potential, or BeRST, scaffold, the new dyes possess an isomeric molecular wire for improved alignment in the plasma membrane and 2′ carboxylic acids for ready functionalization. The new isoBeRST dyes have a voltage sensitivity of 24% ΔF/F per 100 mV. Combined with a flexible polyethyleneglycol (PEG) linker and a chloroalkane HaloTag ligand, isoBeRST dyes enable voltage imaging from genetically defined cells and neurons and provide improved labeling over previous, rhodamine-based hybrid strategies. isoBeRST-Halo hybrid indicators achieve single-trial voltage imaging of membrane potential dynamics from cultured hippocampal neurons or cortical neurons in brain slices. With far-red/near infrared excitation and emission, turn-on response to action potentials, and effective cell labeling in thick tissue, the new isoBeRST-Halo derivatives provide an important complement to voltage imaging in neurobiology. Small-molecule enzyme hybrids pair a far-red voltage-sensitive fluorophore with a cell-surface expressed HaloTag enzyme via a flexible linker to enable voltage imaging from genetically defined neurons in culture and brain slice.![]()
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Affiliation(s)
- Gloria Ortiz
- Department of Chemistry, University of California Berkeley California 94720-1460 USA
| | - Pei Liu
- Department of Chemistry, University of California Berkeley California 94720-1460 USA
| | - Parker E Deal
- Department of Chemistry, University of California Berkeley California 94720-1460 USA
| | - Ashley K Nensel
- Department of Chemistry, University of California Berkeley California 94720-1460 USA
| | - Kayli N Martinez
- Department of Chemistry, University of California Berkeley California 94720-1460 USA
| | - Kiarash Shamardani
- Department of Molecular & Cell Biology, University of California Berkeley California 94720-1460 USA
| | - Hillel Adesnik
- Department of Molecular & Cell Biology, University of California Berkeley California 94720-1460 USA.,Helen Wills Neuroscience Institute, University of California Berkeley California 94720-1460 USA
| | - Evan W Miller
- Department of Chemistry, University of California Berkeley California 94720-1460 USA .,Department of Molecular & Cell Biology, University of California Berkeley California 94720-1460 USA.,Helen Wills Neuroscience Institute, University of California Berkeley California 94720-1460 USA
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34
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Kirk MJ, Benlian BR, Han Y, Gold A, Ravi A, Deal PE, Molina RS, Drobizhev M, Dickman D, Scott K, Miller EW. Voltage Imaging in Drosophila Using a Hybrid Chemical-Genetic Rhodamine Voltage Reporter. Front Neurosci 2021; 15:754027. [PMID: 34867164 PMCID: PMC8637050 DOI: 10.3389/fnins.2021.754027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 10/15/2021] [Indexed: 12/03/2022] Open
Abstract
We combine a chemically-synthesized, voltage-sensitive fluorophore with a genetically encoded, self-labeling enzyme to enable voltage imaging in Drosophila melanogaster. Previously, we showed that a rhodamine voltage reporter (RhoVR) combined with the HaloTag self-labeling enzyme could be used to monitor membrane potential changes from mammalian neurons in culture and brain slice. Here, we apply this hybrid RhoVR-Halo approach in vivo to achieve selective neuron labeling in intact fly brains. We generate a Drosophila UAS-HaloTag reporter line in which the HaloTag enzyme is expressed on the surface of cells. We validate the voltage sensitivity of this new construct in cell culture before driving expression of HaloTag in specific brain neurons in flies. We show that selective labeling of synapses, cells, and brain regions can be achieved with RhoVR-Halo in either larval neuromuscular junction (NMJ) or in whole adult brains. Finally, we validate the voltage sensitivity of RhoVR-Halo in fly tissue via dual-electrode/imaging at the NMJ, show the efficacy of this approach for measuring synaptic excitatory post-synaptic potentials (EPSPs) in muscle cells, and perform voltage imaging of carbachol-evoked depolarization and osmolarity-evoked hyperpolarization in projection neurons and in interoceptive subesophageal zone neurons in fly brain explants following in vivo labeling. We envision the turn-on response to depolarizations, fast response kinetics, and two-photon compatibility of chemical indicators, coupled with the cellular and synaptic specificity of genetically-encoded enzymes, will make RhoVR-Halo a powerful complement to neurobiological imaging in Drosophila.
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Affiliation(s)
- Molly J. Kirk
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, United States
| | - Brittany R. Benlian
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, United States
| | - Yifu Han
- Department of Neurobiology, University of Southern California, Los Angeles, CA, United States
| | - Arya Gold
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, United States
| | - Ashvin Ravi
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, United States
| | - Parker E. Deal
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, United States
| | - Rosana S. Molina
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, United States
| | - Mikhail Drobizhev
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, United States
| | - Dion Dickman
- Department of Neurobiology, University of Southern California, Los Angeles, CA, United States
| | - Kristin Scott
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, United States
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, United States
| | - Evan W. Miller
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, United States
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, United States
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, United States
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35
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Evaluation of the Membrane Damage Mechanism of Chlorogenic Acid against Yersinia enterocolitica and Enterobacter sakazakii and Its Application in the Preservation of Raw Pork and Skim Milk. Molecules 2021; 26:molecules26216748. [PMID: 34771154 PMCID: PMC8587693 DOI: 10.3390/molecules26216748] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 11/02/2021] [Accepted: 11/05/2021] [Indexed: 11/17/2022] Open
Abstract
Plant-derived antimicrobial agents have adequate antimicrobial effects on food-borne pathogens, which can be used as food preservatives. The purpose of this study was to evaluate the antibacterial mechanism of chlorogenic acid (CA) against Yersinia enterocolitica and Enterobacter sakazakii. The minimum inhibitory concentration (MIC) of CA was determined by employing the broth microdilution method. Then, the cell function and morphological changes of Y. enterocolitica and E. sakazakii treated with CA were characterized. Finally, the growth inhibition models of Y. enterocolitica in raw pork and E. sakazakii in skim milk were constructed through the response surface methodology. The results demonstrated that CA has a satisfactory inhibitory effect against Y. enterocolitica and E. sakazakii with a MIC of 2.5 mg/mL. In addition, CA inhibited the growth of Y. enterocolitica and E. sakazakii via cell membrane damage, such as depolarization of the cell membrane, reduction in intracellular adenosine triphosphate (ATP) and pH levels, and destruction of cell morphology. Moreover, CA reduced two log cycles of Y. enterocolitica in raw pork and E. sakazakii in skim milk at a certain temperature. According to the corresponding findings, CA has the potential to be developed as an effective preservative to control Y. enterocolitica and E. sakazakii-associated foodborne diseases.
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Salem T, Frankman Z, Churko J. Tissue engineering techniques for iPSC derived three-dimensional cardiac constructs. TISSUE ENGINEERING PART B-REVIEWS 2021; 28:891-911. [PMID: 34476988 PMCID: PMC9419978 DOI: 10.1089/ten.teb.2021.0088] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Recent developments in applied developmental physiology have provided well-defined methodologies for producing human stem cell derived cardiomyocytes. Cardiomyocytes produced in this way have become commonplace as cardiac physiology research models. This accessibility has also allowed for the development of tissue engineered human heart constructs for drug screening, surgical intervention, and investigating cardiac pathogenesis. However, cardiac tissue engineering is an interdisciplinary field that involves complex engineering and physiological concepts, which limits its accessibility. This review provides a readable, broad reaching, and thorough discussion of major factors to consider for the development of cardiovascular tissues from stem cell derived cardiomyocytes. This review will examine important considerations in undertaking a cardiovascular tissue engineering project, and will present, interpret, and summarize some of the recent advancements in this field. This includes reviewing different forms of tissue engineered constructs, a discussion on cardiomyocyte sources, and an in-depth discussion of the fabrication and maturation procedures for tissue engineered heart constructs.
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Affiliation(s)
- Tori Salem
- University of Arizona Medical Center - University Campus, 22165, Cellular and Molecular Medicine, Tucson, Arizona, United States;
| | - Zachary Frankman
- University of Arizona Medical Center - University Campus, 22165, Biomedical Engineering, Tucson, Arizona, United States;
| | - Jared Churko
- University of Arizona Medical Center - University Campus, 22165, 1501 N Campbell RD, SHC 6143, Tucson, Arizona, United States, 85724-5128;
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Lazzari-Dean JR, Miller EW. Optical Estimation of Absolute Membrane Potential Using One- and Two-Photon Fluorescence Lifetime Imaging Microscopy. Bioelectricity 2021; 3:197-203. [PMID: 34734167 DOI: 10.1089/bioe.2021.0007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Background: Membrane potential (V mem) exerts physiological influence across a wide range of time and space scales. To study V mem in these diverse contexts, it is essential to accurately record absolute values of V mem, rather than solely relative measurements. Materials and Methods: We use fluorescence lifetime imaging of a small molecule voltage sensitive dye (VF2.1.Cl) to estimate mV values of absolute membrane potential. Results: We test the consistency of VF2.1.Cl lifetime measurements performed on different single-photon counting instruments and find that they are in striking agreement (differences of <0.5 ps/mV in the slope and <50 ps in the y-intercept). We also demonstrate that VF2.1.Cl lifetime reports absolute V mem under two-photon (2P) illumination with better than 20 mV of V mem resolution, a nearly 10-fold improvement over other lifetime-based methods. Conclusions: We demonstrate that VF-FLIM is a robust and portable metric for V mem across imaging platforms and under both one-photon and 2P illumination. This work is a critical foundation for application of VF-FLIM to record absolute membrane potential signals in thick tissue.
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Affiliation(s)
- Julia R Lazzari-Dean
- Department of Chemistry, University of California, Berkeley, Berkeley, California, USA
| | - Evan W Miller
- Department of Chemistry, University of California, Berkeley, Berkeley, California, USA.,Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA.,Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, California, USA
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Kiester AS, Ibey BL, Coker ZN, Pakhomov AG, Bixler JN. Strobe photography mapping of cell membrane potential with nanosecond resolution. Bioelectrochemistry 2021; 142:107929. [PMID: 34438186 DOI: 10.1016/j.bioelechem.2021.107929] [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: 10/01/2020] [Revised: 08/07/2021] [Accepted: 08/10/2021] [Indexed: 10/20/2022]
Abstract
The ability to directly observe membrane potential charging dynamics across a full microscopic field of view is vital for understanding interactions between a biological system and a given electrical stimulus. Accurate empirical knowledge of cell membrane electrodynamics will enable validation of fundamental hypotheses posited by the single shell model, which includes the degree of voltage change across a membrane and cellular sensitivity to external electric field non-uniformity and directionality. To this end, we have developed a high-speed strobe microscopy system with a time resolution of ~ 6 ns that allows us to acquire time-sequential data for temporally repeatable events (non-injurious electrostimulation). The imagery from this system allows for direct comparison of membrane voltage change to both computationally simulated external electric fields and time-dependent membrane charging models. Acquisition of a full microscope field of view enables the selection of data from multiple cell locations experiencing different electrical fields in a single image sequence for analysis. Using this system, more realistic membrane parameters can be estimated from living cells to better inform predictive models. As a proof of concept, we present evidence that within the range of membrane conductivity used in simulation literature, higher values are likely more valid.
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Affiliation(s)
- Allen S Kiester
- Bioeffects Division, Airman System Directorate, 711th Human Performance Wing, Air Force Research Laboratory, JBSA Fort Sam Houston, TX, USA
| | - Bennett L Ibey
- Bioeffects Division, Airman System Directorate, 711th Human Performance Wing, Air Force Research Laboratory, JBSA Fort Sam Houston, TX, USA
| | | | - Andrei G Pakhomov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, USA
| | - Joel N Bixler
- Bioeffects Division, Airman System Directorate, 711th Human Performance Wing, Air Force Research Laboratory, JBSA Fort Sam Houston, TX, USA.
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Boggess SC, Gandhi SS, Benlian BR, Miller EW. Vinyl-Fluorene Molecular Wires for Voltage Imaging with Enhanced Sensitivity and Reduced Phototoxicity. J Am Chem Soc 2021; 143:11903-11907. [PMID: 34323478 DOI: 10.1021/jacs.1c04543] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Fluorescent voltage indicators are an attractive alternative for studying the electrical activity of excitable cells; however, the development of indicators that are both highly sensitive and low in toxicity over long-term experiments remains a challenge. Previously, we reported a fluorene-based voltage-sensitive fluorophore that exhibits much lower phototoxicity than previous voltage indicators in cardiomyocyte monolayers, but suffers from low sensitivity to membrane potential changes. Here, we report that the addition of a single vinyl spacer in the fluorene molecular wire scaffold improves the voltage sensitivity 1.5- to 3.5-fold over fluorene-based voltage probes. Furthermore, we demonstrate the improved ability of the new vinyl-fluorene VoltageFluors to monitor action potential kinetics in both mammalian neurons and human-induced pluripotent stem cell-derived cardiomyocytes. Addition of the vinyl spacer between the aniline donor and fluorene monomer results in indicators that are significantly less phototoxic in cardiomyocyte monolayers. These results demonstrate how structural modification to the voltage sensing domain have a large effect on improving the overall properties of molecular wire-based voltage indicators.
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40
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Haris U, Kagalwala HN, Kim YL, Lippert AR. Seeking Illumination: The Path to Chemiluminescent 1,2-Dioxetanes for Quantitative Measurements and In Vivo Imaging. Acc Chem Res 2021; 54:2844-2857. [PMID: 34110136 DOI: 10.1021/acs.accounts.1c00185] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Chemiluminescence is a fascinating phenomenon that evolved in nature and has been harnessed by chemists in diverse ways to improve life. This Account tells the story of our research group's efforts to formulate and manifest spiroadamantane 1,2-dioxetanes with triggerable chemiluminescence for imaging and monitoring important reactive analytes in living cells, animals, and human clinical samples. Analytes like reactive sulfur, oxygen and nitrogen species, as well as pH and hypoxia can be indicators of cellular function or dysfunction and are often implicated in the causes and effects of disease. We begin with a foundation in binding-based and activity-based fluorescence imaging that has provided transformative tools for understanding biological systems. The intense light sources required for fluorescence excitation, however, introduce autofluorescence and light scattering that reduces sensitivity and complicates in vivo imaging. Our work and the work of our collaborators were the first to demonstrate that spiroadamantane 1,2-dioxetanes had sufficient brightness and biological compatibility for in vivo imaging of enzyme activity and reactive analytes like hydrogen sulfide (H2S) inside of living mice. This launched an era of renewed interest in 1,2-dioxetanes that has resulted in a plethora of new chemiluminescence imaging agents developed by groups around the world. Our own research group focused its efforts on reactive sulfur, oxygen, and nitrogen species, pH, and hypoxia, resulting in a large family of bright chemiluminescent 1,2-dioxetanes validated for cell monitoring and in vivo imaging. These chemiluminescent probes feature low background and high sensitivity that have been proven quite useful for studying signaling, for example, the generation of peroxynitrite (ONOO-) in cellular models of immune function and phagocytosis. This high sensitivity has also enabled real-time quantitative reporting of oxygen-dependent enzyme activity and hypoxia in living cells and tumor xenograft models. We reported some of the first ratiometric chemiluminescent 1,2-dioxetane systems for imaging pH and have introduced a powerful kinetics-based approach for quantification of reactive species like azanone (nitroxyl, HNO) and enzyme activity in living cells. These tools have been applied to untangle complex signaling pathways of peroxynitrite production in radiation therapy and as substrates in a split esterase system to provide an enzyme/substrate pair to rival luciferase/luciferin. Furthermore, we have pushed chemiluminescence toward commercialization and clinical translation by demonstrating the ability to monitor airway hydrogen peroxide in the exhaled breath of asthma patients using transiently produced chemiluminescent 1,2-dioxetanedione intermediates. This body of work shows the powerful possibilities that can emerge when working at the interface of light and chemistry, and we hope that it will inspire future scientists to seek out ever brighter and more illuminating ideas.
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Affiliation(s)
- Uroob Haris
- Department of Chemistry, Southern Methodist University, Dallas, Texas 75275-0314, United States
| | - Husain N. Kagalwala
- Department of Chemistry, Southern Methodist University, Dallas, Texas 75275-0314, United States
| | - Yujin Lisa Kim
- Department of Chemistry, Southern Methodist University, Dallas, Texas 75275-0314, United States
| | - Alexander R. Lippert
- Department of Chemistry, Southern Methodist University, Dallas, Texas 75275-0314, United States
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Broichhagen J, Kilian N. Chemical Biology Tools To Investigate Malaria Parasites. Chembiochem 2021; 22:2219-2236. [PMID: 33570245 PMCID: PMC8360121 DOI: 10.1002/cbic.202000882] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/10/2021] [Indexed: 02/06/2023]
Abstract
Parasitic diseases like malaria tropica have been shaping human evolution and history since the beginning of mankind. After infection, the response of the human host ranges from asymptomatic to severe and may culminate in death. Therefore, proper examination of the parasite's biology is pivotal to deciphering unique molecular, biochemical and cell biological processes, which in turn ensure the identification of treatment strategies, such as potent drug targets and vaccine candidates. However, implementing molecular biology methods for genetic manipulation proves to be difficult for many parasite model organisms. The development of fast and straightforward applicable alternatives, for instance small-molecule probes from the field of chemical biology, is essential. In this review, we will recapitulate the highlights of previous molecular and chemical biology approaches that have already created insight and understanding of the malaria parasite Plasmodium falciparum. We discuss current developments from the field of chemical biology and explore how their application could advance research into this parasite in the future. We anticipate that the described approaches will help to close knowledge gaps in the biology of P. falciparum and we hope that researchers will be inspired to use these methods to gain knowledge - with the aim of ending this devastating disease.
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Affiliation(s)
- Johannes Broichhagen
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP)Robert-Roessle-Strasse 1013125BerlinGermany
| | - Nicole Kilian
- Centre for Infectious DiseasesParasitologyHeidelberg University HospitalIm Neuenheimer Feld 32469120HeidelbergGermany
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Raliski BK, Kirk MJ, Miller EW. Imaging Spontaneous Neuronal Activity with Voltage-Sensitive Dyes. Curr Protoc 2021; 1:e48. [PMID: 33760396 DOI: 10.1002/cpz1.48] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Accurately mapping changes in cellular membrane potential across large groups of neurons is crucial for understanding the organization and maintenance of neural circuits. Measuring cellular voltage changes by optical means allows greater spatial resolution than traditional electrophysiology methods and is adaptable to high-throughput imaging experiments. VoltageFluors, a class of voltage-sensitive dyes, have recently been used to optically study the spontaneous activity of many neurons simultaneously in dissociated culture. VoltageFluors are particularly useful for experiments investigating differences in excitability and connectivity between neurons at different stages of development and in different disease models. The protocols in this article describe general procedures for preparing dissociated cultures, imaging spontaneous activity in dissociated cultures with VoltageFluors, and analyzing optical spontaneous activity data. © 2021 Wiley Periodicals LLC. Basic Protocol 1: Preparation of dissociated rat hippocampal or cortical cultures Alternate Protocol: Preparation of microisland dissociated cultures Basic Protocol 2: Imaging of spontaneous activity in dissociated cultures using voltage-sensitive dyes Basic Protocol 3: Analysis of spontaneous activity imaging data.
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Affiliation(s)
- Benjamin K Raliski
- Department of Chemistry, University of California Berkeley, Berkeley, California
| | - Molly J Kirk
- Department of Molecular & Cell Biology, University of California Berkeley, Berkeley, California
| | - Evan W Miller
- Department of Chemistry, University of California Berkeley, Berkeley, California.,Department of Molecular & Cell Biology, University of California Berkeley, Berkeley, California.,Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, California
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43
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Yu Q, Wang X, Nie L. Optical recording of brain functions based on voltage-sensitive dyes. CHINESE CHEM LETT 2021. [DOI: 10.1016/j.cclet.2020.12.060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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44
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Current problems and future avenues in proteoliposome research. Biochem Soc Trans 2021; 48:1473-1492. [PMID: 32830854 DOI: 10.1042/bst20190966] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 07/10/2020] [Accepted: 07/14/2020] [Indexed: 12/11/2022]
Abstract
Membrane proteins (MPs) are the gatekeepers between different biological compartments separated by lipid bilayers. Being receptors, channels, transporters, or primary pumps, they fulfill a wide variety of cellular functions and their importance is reflected in the increasing number of drugs that target MPs. Functional studies of MPs within a native cellular context, however, is difficult due to the innate complexity of the densely packed membranes. Over the past decades, detergent-based extraction and purification of MPs and their reconstitution into lipid mimetic systems has been a very powerful tool to simplify the experimental system. In this review, we focus on proteoliposomes that have become an indispensable experimental system for enzymes with a vectorial function, including many of the here described energy transducing MPs. We first address long standing questions on the difficulty of successful reconstitution and controlled orientation of MPs into liposomes. A special emphasis is given on coreconstitution of several MPs into the same bilayer. Second, we discuss recent progress in the development of fluorescent dyes that offer sensitive detection with high temporal resolution. Finally, we briefly cover the use of giant unilamellar vesicles for the investigation of complex enzymatic cascades, a very promising experimental tool considering our increasing knowledge of the interplay of different cellular components.
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45
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Walker AS, Raliski BK, Karbasi K, Zhang P, Sanders K, Miller EW. Optical Spike Detection and Connectivity Analysis With a Far-Red Voltage-Sensitive Fluorophore Reveals Changes to Network Connectivity in Development and Disease. Front Neurosci 2021; 15:643859. [PMID: 34054405 PMCID: PMC8155641 DOI: 10.3389/fnins.2021.643859] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 03/10/2021] [Indexed: 12/14/2022] Open
Abstract
The ability to optically record dynamics of neuronal membrane potential promises to revolutionize our understanding of neurobiology. In this study, we show that the far-red voltage sensitive fluorophore, Berkeley Red Sensor of Transmembrane potential-1, or BeRST 1, can be used to monitor neuronal membrane potential changes across dozens of neurons at a sampling rate of 500 Hz. Notably, voltage imaging with BeRST 1 can be implemented with affordable, commercially available illumination sources, optics, and detectors. BeRST 1 is well-tolerated in cultures of rat hippocampal neurons and provides exceptional optical recording fidelity, as judged by dual fluorescence imaging and patch-clamp electrophysiology. We developed a semi-automated spike-picking program to reduce user bias when calling action potentials and used this in conjunction with BeRST 1 to develop an optical spike and connectivity analysis (OSCA) for high-throughput dissection of neuronal activity dynamics. The high temporal resolution of BeRST 1 enables dissection of firing rate changes in response to acute, pharmacological interventions with commonly used inhibitors like gabazine and picrotoxin. Over longer periods of time, BeRST 1 also tracks chronic perturbations to neurons exposed to amyloid beta 1-42 (Aβ 1-42), revealing modest changes to spiking frequency but profound changes to overall network connectivity. Finally, we use OSCA to track changes in neuronal connectivity during maturation in culture, providing a functional readout of network assembly. We envision that use of BeRST 1 and OSCA described here will be of use to the broad neuroscience community.
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Affiliation(s)
- Alison S. Walker
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, United States
- Department of Molecular & Cell Biology, University of California, Berkeley, Berkeley, CA, United States
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, United States
| | - Benjamin K. Raliski
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, United States
| | - Kaveh Karbasi
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, United States
| | - Patrick Zhang
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, United States
| | - Kate Sanders
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, United States
| | - Evan W. Miller
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, United States
- Department of Molecular & Cell Biology, University of California, Berkeley, Berkeley, CA, United States
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, United States
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46
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Walker AS, Raliski BK, Nguyen DV, Zhang P, Sanders K, Karbasi K, Miller EW. Imaging Voltage in Complete Neuronal Networks Within Patterned Microislands Reveals Preferential Wiring of Excitatory Hippocampal Neurons. Front Neurosci 2021; 15:643868. [PMID: 34054406 PMCID: PMC8155642 DOI: 10.3389/fnins.2021.643868] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 01/28/2021] [Indexed: 12/30/2022] Open
Abstract
Voltage imaging with fluorescent dyes affords the opportunity to map neuronal activity in both time and space. One limitation to imaging is the inability to image complete neuronal networks: some fraction of cells remains outside of the observation window. Here, we combine voltage imaging, post hoc immunocytochemistry, and patterned microisland hippocampal culture to provide imaging of complete neuronal ensembles. The patterned microislands completely fill the field of view of our high-speed (500 Hz) camera, enabling reconstruction of the spiking patterns of every single neuron in the network. Cultures raised on microislands are similar to neurons grown on coverslips, with parallel developmental trajectories and composition of inhibitory and excitatory cell types (CA1, CA3, and dentate granule cells, or DGC). We calculate the likelihood that action potential firing in one neuron triggers action potential firing in a downstream neuron in a spontaneously active network to construct a functional connection map of these neuronal ensembles. Importantly, this functional map indicates preferential connectivity between DGC and CA3 neurons and between CA3 and CA1 neurons, mimicking the neuronal circuitry of the intact hippocampus. We envision that patterned microislands, in combination with voltage imaging and methods to classify cell types, will be a powerful method for exploring neuronal function in both healthy and disease states. Additionally, because the entire neuronal network is sampled simultaneously, this strategy has the power to go further, revealing all functional connections between all cell types.
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Affiliation(s)
- Alison S. Walker
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, United States
- Department of Molecular & Cell Biology, University of California, Berkeley, Berkeley, CA, United States
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, United States
| | - Benjamin K. Raliski
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, United States
| | - Dat Vinh Nguyen
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, United States
| | - Patrick Zhang
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, United States
| | - Kate Sanders
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, United States
| | - Kaveh Karbasi
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, United States
| | - Evan W. Miller
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, United States
- Department of Molecular & Cell Biology, University of California, Berkeley, Berkeley, CA, United States
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, United States
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47
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Piazzolla F, Mercier V, Assies L, Sakai N, Roux A, Matile S. Fluorescent Membrane Tension Probes for Early Endosomes. Angew Chem Int Ed Engl 2021; 60:12258-12263. [DOI: 10.1002/anie.202016105] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 01/18/2020] [Indexed: 12/19/2022]
Affiliation(s)
- Francesca Piazzolla
- School of Chemistry and Biochemistry National Centre of Competence in Research (NCCR) Chemical Biology University of Geneva Geneva Switzerland
| | - Vincent Mercier
- School of Chemistry and Biochemistry National Centre of Competence in Research (NCCR) Chemical Biology University of Geneva Geneva Switzerland
| | - Lea Assies
- School of Chemistry and Biochemistry National Centre of Competence in Research (NCCR) Chemical Biology University of Geneva Geneva Switzerland
| | - Naomi Sakai
- School of Chemistry and Biochemistry National Centre of Competence in Research (NCCR) Chemical Biology University of Geneva Geneva Switzerland
| | - Aurelien Roux
- School of Chemistry and Biochemistry National Centre of Competence in Research (NCCR) Chemical Biology University of Geneva Geneva Switzerland
| | - Stefan Matile
- School of Chemistry and Biochemistry National Centre of Competence in Research (NCCR) Chemical Biology University of Geneva Geneva Switzerland
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48
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Piazzolla F, Mercier V, Assies L, Sakai N, Roux A, Matile S. Fluorescent Membrane Tension Probes for Early Endosomes. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202016105] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Francesca Piazzolla
- School of Chemistry and Biochemistry National Centre of Competence in Research (NCCR) Chemical Biology University of Geneva Geneva Switzerland
| | - Vincent Mercier
- School of Chemistry and Biochemistry National Centre of Competence in Research (NCCR) Chemical Biology University of Geneva Geneva Switzerland
| | - Lea Assies
- School of Chemistry and Biochemistry National Centre of Competence in Research (NCCR) Chemical Biology University of Geneva Geneva Switzerland
| | - Naomi Sakai
- School of Chemistry and Biochemistry National Centre of Competence in Research (NCCR) Chemical Biology University of Geneva Geneva Switzerland
| | - Aurelien Roux
- School of Chemistry and Biochemistry National Centre of Competence in Research (NCCR) Chemical Biology University of Geneva Geneva Switzerland
| | - Stefan Matile
- School of Chemistry and Biochemistry National Centre of Competence in Research (NCCR) Chemical Biology University of Geneva Geneva Switzerland
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49
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Turnbull JL, Benlian BR, Golden RP, Miller EW. Phosphonofluoresceins: Synthesis, Spectroscopy, and Applications. J Am Chem Soc 2021; 143:6194-6201. [PMID: 33797899 DOI: 10.1021/jacs.1c01139] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Xanthene fluorophores, like fluorescein, have been versatile molecules across diverse fields of chemistry and life sciences. Despite the ubiquity of 3-carboxy and 3-sulfonofluorescein for the last 150 years, to date, no reports of 3-phosphonofluorescein exist. Here, we report the synthesis, spectroscopic characterization, and applications of 3-phosphonofluoresceins. The absorption and emission of 3-phosphonofluoresceins remain relatively unaltered from the parent 3-carboxyfluorescein. 3-Phosphonofluoresceins show enhanced water solubility compared to 3-carboxyfluorescein and persist in an open, visible light-absorbing state even at low pH and in low dielectric media while 3-carboxyfluoresceins tend to lactonize. In contrast, the spirocyclization tendency of 3-phosphonofluoresceins can be modulated by esterification of the phosphonic acid. The bis-acetoxymethyl ester of 3-phosphonofluorescein readily enters living cells, showing excellent accumulation (>6x) and retention (>11x), resulting in a nearly 70-fold improvement in cellular brightness compared to 3-carboxyfluorescein. In a complementary fashion, the free acid form of 3-phosphonofluorescein does not cross cellular membranes, making it ideally suited for incorporation into a voltage-sensing scaffold. We develop a new synthetic route to functionalized 3-phosphonofluoresceins to enable the synthesis of phosphono-voltage sensitive fluorophores, or phosVF2.1.Cl. Phosphono-VF2.1.Cl shows excellent membrane localization, cellular brightness, and voltage sensitivity (26% ΔF/F per 100 mV), rivaling that of sulfono-based VF dyes. In summary, we develop the first synthesis of 3-phosphonofluoresceins, characterize the spectroscopic properties of this new class of xanthene dyes, and utilize these insights to show the utility of 3-phosphonofluoresceins in intracellular imaging and membrane potential sensing.
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50
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García-Calvo J, López-Andarias J, Sakai N, Matile S. The primary dipole of flipper probes. Chem Commun (Camb) 2021; 57:3913-3916. [PMID: 33871529 DOI: 10.1039/d1cc00860a] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Despite their growing popularity in biology to image membrane tension, central design principles of flipper probes have never been validated. Here we report that upon deletion of their primary dipole, from electron-poor and electron-rich dithienothiophenes, absorptions blue-shift, lifetimes shorten dramatically, and mechanosensitivity in cells vanishes not partially, but completely.
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Affiliation(s)
- José García-Calvo
- Department of Organic Chemistry, University of Geneva, Geneva, Switzerland.
| | | | - Naomi Sakai
- Department of Organic Chemistry, University of Geneva, Geneva, Switzerland.
| | - Stefan Matile
- Department of Organic Chemistry, University of Geneva, Geneva, Switzerland.
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