1
|
Li B, Li J, Chen S, Yuan Q, Fang C, Gan W. Monitoring the response of a model protocell to dye and surfactant molecules through second harmonic generation and fluorescence imaging. Phys Chem Chem Phys 2024; 26:8148-8157. [PMID: 38380536 DOI: 10.1039/d4cp00009a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Probing the interaction between molecules and protocells is crucial for understanding the passive transport of functional molecules in and out of artificial and real cells. Second-harmonic generation (SHG) has been proven to be a powerful method for analyzing the adsorption and cross-membrane transport of molecules on lipid bilayers. In this study, we used SHG and two-photon fluorescence (TPF) imaging to study the interaction of charged dye molecules (D289) with a lipid vesicle. Unexpectedly, it was observed that the transport of D289 at a relatively high concentration is not as efficient as that at a lower dye concentration. Periodic shrinking of the model protocell and discharging of D289 out from the vesicle were revealed by combined analyses of SHG and TPF images. The response of the vesicle to a surfactant was also analyzed with D289 as a probe. This work demonstrates that the combined SHG and TPF imaging method is a unique approach that can provide detailed information on the interaction of molecules and lipids (both morphology and molecular kinetics). Determining these subtle interfacial kinetics in molecules is important for understanding the mechanism of many biophysical processes occurring on lipids.
Collapse
Affiliation(s)
- Bifei Li
- Shenzhen Key Laboratory of Flexible Printed Electronics Technology, School of Science, Harbin Institute of Technology (Shenzhen), University Town, Shenzhen 518055, Guangdong, China.
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, Heilongjiang, China
| | - Jianhui Li
- Shenzhen Key Laboratory of Flexible Printed Electronics Technology, School of Science, Harbin Institute of Technology (Shenzhen), University Town, Shenzhen 518055, Guangdong, China.
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, Heilongjiang, China
| | - Shujiao Chen
- Shenzhen Key Laboratory of Flexible Printed Electronics Technology, School of Science, Harbin Institute of Technology (Shenzhen), University Town, Shenzhen 518055, Guangdong, China.
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, Heilongjiang, China
| | - Qunhui Yuan
- Shenzhen Key Laboratory of Flexible Printed Electronics Technology, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), University Town, Shenzhen 518055, Guangdong, China.
| | - Chao Fang
- Shenzhen Key Laboratory of Flexible Printed Electronics Technology, School of Science, Harbin Institute of Technology (Shenzhen), University Town, Shenzhen 518055, Guangdong, China.
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, Heilongjiang, China
| | - Wei Gan
- Shenzhen Key Laboratory of Flexible Printed Electronics Technology, School of Science, Harbin Institute of Technology (Shenzhen), University Town, Shenzhen 518055, Guangdong, China.
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, Heilongjiang, China
| |
Collapse
|
2
|
Mao W, Bui HTD, Cho W, Yoo HS. Spectroscopic techniques for monitoring stem cell and organoid proliferation in 3D environments for therapeutic development. Adv Drug Deliv Rev 2023; 201:115074. [PMID: 37619771 DOI: 10.1016/j.addr.2023.115074] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 07/22/2023] [Accepted: 08/20/2023] [Indexed: 08/26/2023]
Abstract
Spectroscopic techniques for monitoring stem cell and organoid proliferation have gained significant attention in therapeutic development. Spectroscopic techniques such as fluorescence, Raman spectroscopy, and infrared spectroscopy offer noninvasive and real-time monitoring of biochemical and biophysical changes that occur during stem cell and organoid proliferation. These techniques provide valuable insight into the underlying mechanisms of action of potential therapeutic agents, allowing for improved drug discovery and screening. This review highlights the importance of spectroscopic monitoring of stem cell and organoid proliferation and its potential impact on therapeutic development. Furthermore, this review discusses recent advances in spectroscopic techniques and their applications in stem cell and organoid research. Overall, this review emphasizes the importance of spectroscopic techniques as valuable tools for studying stem cell and organoid proliferation and their potential to revolutionize therapeutic development in the future.
Collapse
Affiliation(s)
- Wei Mao
- Department of Biomedical Materials Engineering, Kangwon National University, Chuncheon 24341, Republic of Korea; Institute for Molecular Science and Fusion Technology, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Hoai-Thuong Duc Bui
- Department of Biomedical Materials Engineering, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Wanho Cho
- Department of Biomedical Materials Engineering, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Hyuk Sang Yoo
- Department of Biomedical Materials Engineering, Kangwon National University, Chuncheon 24341, Republic of Korea; Institute for Molecular Science and Fusion Technology, Kangwon National University, Chuncheon 24341, Republic of Korea; Institue of Biomedical Science, Kangwon National University, Chuncheon 24341, Republic of Korea; Kangwon Radiation Convergence Research Support Center, Kangwon National University, Chuncheon 24341, Republic of Korea.
| |
Collapse
|
3
|
Blake MJ, Castillo HB, Curtis AE, Calhoun TR. Facilitating flip-flop: Structural tuning of molecule-membrane interactions in living bacteria. Biophys J 2023; 122:1735-1747. [PMID: 37041744 PMCID: PMC10209030 DOI: 10.1016/j.bpj.2023.04.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 03/17/2023] [Accepted: 04/04/2023] [Indexed: 04/13/2023] Open
Abstract
The first barrier that a small molecule must overcome before trespassing into a living cell is the lipid bilayer surrounding the intracellular content. It is imperative, therefore, to understand how the structure of a small molecule influences its fate in this region. Through the use of second harmonic generation, we show how the differing degrees of ionic headgroups, conjugated system, and branched hydrocarbon tail disparities of a series of four styryl dye molecules influence the propensity to "flip-flop" or to be further organized in the outer leaflet by the membrane. We show here that initial adsorption experiments match previous studies on model systems; however, more complex dynamics are observed over time. Aside from probe molecule structure, these dynamics also vary between cell species and can deviate from trends reported based on model membranes. Specifically, we show here that the membrane composition is an important factor to consider for headgroup-mediated small-molecule dynamics. Overall, the findings presented here on how structural variability of small molecules impacts their initial adsorption and eventual destinations within membranes in the context of living cells could have practical applications in antibiotic and drug adjuvant design.
Collapse
Affiliation(s)
- Marea J Blake
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee
| | - Hannah B Castillo
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee
| | - Anna E Curtis
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee
| | - Tessa R Calhoun
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee.
| |
Collapse
|
4
|
Dianat M, Münchberg U, Blank LM, Freier E, Ebert BE. Non-invasive monitoring of microbial triterpenoid production using nonlinear microscopy techniques. Front Bioeng Biotechnol 2023; 11:1106566. [PMID: 36926686 PMCID: PMC10012247 DOI: 10.3389/fbioe.2023.1106566] [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: 11/23/2022] [Accepted: 01/23/2023] [Indexed: 03/08/2023] Open
Abstract
Introduction: Bioproduction of plant-derived triterpenoids in recombinant microbes is receiving great attention to make these biologically active compounds industrially accessible as nutraceuticals, pharmaceutics, and cosmetic ingredients. So far, there is no direct method for detecting triterpenoids under physiological conditions on a cellular level, information yet highly relevant to rationalizing microbial engineering. Methods: Here, we show in a proof-of-concept study, that triterpenoids can be detected and monitored in living yeast cells by combining coherent anti-Stokes Raman scattering (CARS) and second-harmonic-generation (SHG) microscopy techniques. We applied CARS and SHG microscopy measurements, and for comparison classical Nile Red staining, on immobilized and growing triterpenoid-producing, and non-producing reference Saccharomyces cerevisiae strains. Results and Discussion: We found that the SHG signal in triterpenoid-producing strains is significantly higher than in a non-producing reference strain, correlating with lipophile content as determined by Nile red staining. In growing cultures, both CARS and SHG signals showed changes over time, enabling new insights into the dynamics of triterpenoid production and storage inside cells.
Collapse
Affiliation(s)
- Mariam Dianat
- Institute of Applied Microbiology (iAMB), Aachen Biology and Biotechnology (ABBt), RWTH Aachen University, Aachen, Germany
| | - Ute Münchberg
- University Development and Strategy, Ruhr University Bochum, Bochum, Germany
| | - Lars M Blank
- Institute of Applied Microbiology (iAMB), Aachen Biology and Biotechnology (ABBt), RWTH Aachen University, Aachen, Germany
| | - Erik Freier
- Interdisciplinary Center for Machine Learning and Data Analytics (IZMD), University of Wuppertal, Wuppertal, Germany
| | - Birgitta E Ebert
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, Australia
| |
Collapse
|
5
|
Page EF, Blake MJ, Foley GA, Calhoun TR. Monitoring membranes: The exploration of biological bilayers with second harmonic generation. CHEMICAL PHYSICS REVIEWS 2022; 3:041307. [PMID: 36536669 PMCID: PMC9756348 DOI: 10.1063/5.0120888] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 11/03/2022] [Indexed: 12/23/2022]
Abstract
Nature's seemingly controlled chaos in heterogeneous two-dimensional cell membranes stands in stark contrast to the precise, often homogeneous, environment in an experimentalist's flask or carefully designed material system. Yet cell membranes can play a direct role, or serve as inspiration, in all fields of biology, chemistry, physics, and engineering. Our understanding of these ubiquitous structures continues to evolve despite over a century of study largely driven by the application of new technologies. Here, we review the insight afforded by second harmonic generation (SHG), a nonlinear optical technique. From potential measurements to adsorption and diffusion on both model and living systems, SHG complements existing techniques while presenting a large exploratory space for new discoveries.
Collapse
Affiliation(s)
- Eleanor F. Page
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Marea J. Blake
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Grant A. Foley
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Tessa R. Calhoun
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, USA
| |
Collapse
|
6
|
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.
Collapse
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.
| |
Collapse
|
7
|
Mizuguchi T, Nuriya M. Applications of second harmonic generation (SHG)/sum-frequency generation (SFG) imaging for biophysical characterization of the plasma membrane. Biophys Rev 2020; 12:10.1007/s12551-020-00768-4. [PMID: 33108561 PMCID: PMC7755958 DOI: 10.1007/s12551-020-00768-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Accepted: 10/20/2020] [Indexed: 12/12/2022] Open
Abstract
The plasma membrane is a lipid bilayer of < 10 nm width that separates intra- and extra-cellular environments and serves as the site of cell-cell communication, as well as communication between cells and the extracellular environment. As such, biophysical phenomena at and around the plasma membrane play key roles in determining cellular physiology and pathophysiology. Thus, the selective visualization and characterization of the plasma membrane are crucial aspects of research in wide areas of biology and medicine. However, the specific characterization of the plasma membrane has been a challenge using conventional imaging techniques, which are unable to effectively distinguish between signals arising from the plasma membrane and those from intracellular lipid structures. In this regard, interface-specific second harmonic generation (SHG) and sum-frequency generation (SFG) imaging demonstrate great potential. When combined with exogenous SHG/SFG active dyes, SHG/SFG can specifically highlight the plasma membrane as the most prominent interface associated with cells. Furthermore, SHG/SFG imaging can be readily extended to multimodal multiphoton microscopy with simultaneous occurrence of other multiphoton phenomena, including multiphoton excitation and coherent Raman scattering, which shed light on the biophysical properties of the plasma membrane from different perspectives. Here, we review traditional and current applications, as well as the prospects of long-known but unexplored SHG/SFG imaging techniques in biophysics, with special focus on their use in the biophysical characterization of the plasma membrane.
Collapse
Affiliation(s)
- Takaha Mizuguchi
- Department of Pharmacology School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Mutsuo Nuriya
- Department of Pharmacology School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
- Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), Kawaguchi, Saitama, 332-0012, Japan.
- Keio Advanced Research Center for Water Biology and Medicine, Keio University, 2-15-45 Mita, Minato-ku, Tokyo, 108-8345, Japan.
- Graduate School of Environment and Information Sciences, Yokohama National University, 79-7 Tokiwadai, Hodogaya, Yokohama, Kanagawa, 240-8501, Japan.
| |
Collapse
|
8
|
Tolstykh GP, Cantu JC, Tarango M, Ibey BL. Receptor- and store-operated mechanisms of calcium entry during the nanosecond electric pulse-induced cellular response. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1861:685-696. [PMID: 30552899 DOI: 10.1016/j.bbamem.2018.12.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 12/07/2018] [Accepted: 12/10/2018] [Indexed: 11/16/2022]
Abstract
Nanosecond electric pulses have been shown to open nanopores in the cell plasma membrane by fluorescent imaging of calcium uptake and fluorescent dyes, including propidium (Pr) iodide and YO-PRO-1 (YP1). Recently, we demonstrated that nsEPs also induce the phosphoinositide intracellular signaling cascade by phosphatidylinositol-4,5-bisphosphate (PIP2) depletion resulting in physiological responses similar to those observed following stimulation of Gq11-coupled receptors. In this paper, we explore the role of receptor- and store-operated calcium entry (ROCE/SOCE) mechanisms in the observed response of cells to nsEP. We show that addition of the ROCE/SOCE and transient receptor potential channel (TRPC) blocker gadolinium (Gd3+, 300 μM) slows PIP2 depletion following 1 and 20 nsEP exposures. Lipid rafts, regions of the plasma membrane rich in PIP2 and TRPC, are also disrupted by nsEP exposure suggesting that ROCE/SOCE mechanisms are likely impacted. Reducing the expression of stromal interaction molecule 1 (STIM1) protein, a key protein in ROCE and SOCE, in cells exposure to nsEP resulted in a reduction in induced intracellular calcium rise. Additionally, after exposure to 1 and 20 nsEPs (16.2 kV/cm, 5 Hz), intracellular calcium rises were significantly reduced by the addition of GD3+ and SKF-96365 (1-[2-(4-methoxyphenyl)-2-[3-(4-methoxyphenyl) propoxy] ethyl-1H-imidazole hydrochloride, 100 μM), a blocker of STIM1 interaction. However, using similar nsEP exposure parameters, SKF-96365 was less effective at reducing YP1 uptake compared to Gd3+. Thus, it is possible that SKF-96365 could block STIM1 interactions within the cell, while Gd3+ could acts on TRPC/nanopores from outside of the cell. Our results present evidence of nsEP induces ROCE and SOCE mechanisms and demonstrate that YP1 and Ca2+ cannot be used solely as markers of nsEP-induced nanoporation.
Collapse
Affiliation(s)
- Gleb P Tolstykh
- General Dynamics Information Technology, 4141 Petroleum Road, JBSA Fort Sam Houston, TX 78234, USA.
| | - Jody C Cantu
- General Dynamics Information Technology, 4141 Petroleum Road, JBSA Fort Sam Houston, TX 78234, USA
| | - Melissa Tarango
- General Dynamics Information Technology, 4141 Petroleum Road, JBSA Fort Sam Houston, TX 78234, USA
| | - Bennett L Ibey
- Air Force Research Laboratory, 711th Human Performance Wing, Airman Systems Directorate, Bioeffects Division, Radio Frequency Bioeffects Branch, 4141 Petroleum Road, JBSA Fort Sam Houston, TX 78234, USA
| |
Collapse
|
9
|
Mizuguchi T, Yasui M, Nuriya M. High-Resolution Plasma Membrane-Selective Imaging by Second Harmonic Generation. iScience 2018; 9:359-366. [PMID: 30466062 PMCID: PMC6249386 DOI: 10.1016/j.isci.2018.11.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 10/01/2018] [Accepted: 11/01/2018] [Indexed: 12/22/2022] Open
Abstract
The plasma membrane is the site of intercellular communication and subsequent intracellular signal transduction. The specific visualization of the plasma membrane in living cells, however, is difficult using fluorescence-based techniques owing to the high background signals from intracellular organelles. In this study, we show that second harmonic generation (SHG) is a high-resolution plasma membrane-selective imaging technique that enables multifaceted investigations of the plasma membrane. In contrast to fluorescence imaging, SHG specifically visualizes the plasma membrane at locations that are not attached to artificial substrates and allows high-resolution imaging because of its subresolution nature. These properties were exploited to measure the distances from the plasma membrane to subcortical actin and tubulin fibers, revealing the precise cytoskeletal organization beneath the plasma membrane. Thus, SHG imaging enables the specific visualization of phenomena at the plasma membrane with unprecedented precision and versatility and should facilitate cell biology research focused on the plasma membrane. Dye-based SHG imaging can specifically visualize the plasma membrane SHG imaging can identify the location of the plasma membrane with high precision Multimodal imaging reveals the precise organization of subcortical cytoskeletons
Collapse
Affiliation(s)
- Takaha Mizuguchi
- Department of Pharmacology School of Medicine, Keio University, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Masato Yasui
- Department of Pharmacology School of Medicine, Keio University, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Mutsuo Nuriya
- Department of Pharmacology School of Medicine, Keio University, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan; Graduate School of Environment and Information Sciences, Yokohama National University, Kanagawa 240-8501, Japan; Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan.
| |
Collapse
|
10
|
Batista Napotnik T, Miklavčič D. In vitro electroporation detection methods – An overview. Bioelectrochemistry 2018; 120:166-182. [DOI: 10.1016/j.bioelechem.2017.12.005] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 12/11/2017] [Accepted: 12/11/2017] [Indexed: 12/22/2022]
|
11
|
Valdez CM, Barnes RA, Roth CC, Moen EK, Throckmorton GA, Ibey BL. Asymmetrical bipolar nanosecond electric pulse widths modify bipolar cancellation. Sci Rep 2017; 7:16372. [PMID: 29180756 PMCID: PMC5703993 DOI: 10.1038/s41598-017-16142-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 11/03/2017] [Indexed: 12/20/2022] Open
Abstract
A bipolar (BP) nanosecond electric pulse (nsEP) exposure generates reduced calcium influx compared to a unipolar (UP) nsEP. This attenuated physiological response from a BP nsEP exposure is termed "bipolar cancellation" (BPC). The predominant BP nsEP parameters that induce BPC consist of a positive polarity (↑) front pulse followed by the delivery of a negative polarity (↓) back pulse of equal voltage and width; thereby the duration is twice a UP nsEP exposure. We tested these BPC parameters, and discovered that a BP nsEP with symmetrical pulse widths is not required to generate BPC. For example, our data revealed the physiological response initiated by a ↑900 nsEP exposure can be cancelled by a second pulse that is a third of its duration. However, we observed a complete loss of BPC from a ↑300 nsEP followed by a ↓900 nsEP exposure. Spatiotemporal analysis revealed these asymmetrical BP nsEP exposures generate distinct local YO-PRO®-1 uptake patterns across the plasma membrane. From these findings, we generated a conceptual model that suggests BPC is a phenomenon balanced by localized charging and discharging events across the membrane.
Collapse
Affiliation(s)
- Chris M Valdez
- National Research Council Research Associateship Program, Air Force Research Laboratory, 4141 Petroleum Rd., JBSA Fort Sam Houston, Texas, 78234, USA
| | - Ronald A Barnes
- Radio Frequency Bioeffects Branch, Bioeffects Division, Airman Systems Directorate, 711th Human Performance Wing, Air Force Research Laboratory, 4141 Petroleum Rd., JBSA Fort Sam Houston, Texas, 78234, USA
| | - Caleb C Roth
- Radio Frequency Bioeffects Branch, Bioeffects Division, Airman Systems Directorate, 711th Human Performance Wing, Air Force Research Laboratory, 4141 Petroleum Rd., JBSA Fort Sam Houston, Texas, 78234, USA
| | - Erick K Moen
- Ming Hsieh Department of Electrical Engineering- Electrophysics, University of Southern California, 920 Bloom Walk, SSC, 502, Los Angeles, California, USA
| | - Graham A Throckmorton
- Department of Biomedical Engineering, Vanderbilt University, 2301 Vanderbilt Place, Nashville, Tennessee, 37235, USA
| | - Bennett L Ibey
- Radio Frequency Bioeffects Branch, Bioeffects Division, Airman Systems Directorate, 711th Human Performance Wing, Air Force Research Laboratory, 4141 Petroleum Rd., JBSA Fort Sam Houston, Texas, 78234, USA.
| |
Collapse
|
12
|
Moen EK, Ibey BL, Beier HT, Armani AM. Quantifying pulsed electric field-induced membrane nanoporation in single cells. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:2795-2803. [PMID: 27535877 DOI: 10.1016/j.bbamem.2016.08.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 08/11/2016] [Accepted: 08/12/2016] [Indexed: 12/21/2022]
Abstract
Plasma membrane disruption can trigger a host of cellular activities. One commonly observed type of disruption is pore formation. Molecular dynamic (MD) simulations of simplified lipid membrane structures predict that controllably disrupting the membrane via nano-scale poration may be possible with nanosecond pulsed electric fields (nsPEF). Until recently, researchers hoping to verify this hypothesis experimentally have been limited to measuring the relatively slow process of fluorescent markers diffusing across the membrane, which is indirect evidence of nanoporation that could be channel-mediated. Leveraging recent advances in nonlinear optical microscopy, we elucidate the role of pulse parameters in nsPEF-induced membrane permeabilization in live cells. Unlike previous techniques, it is able to directly observe loss of membrane order at the onset of the pulse. We also develop a complementary theoretical model that relates increasing membrane permeabilization to membrane pore density. Due to the significantly improved spatial and temporal resolution possible with our imaging method, we are able to directly compare our experimental and theoretical results. Their agreement provides substantial evidence that nanoporation does occur and that its development is dictated by the electric field distribution.
Collapse
Affiliation(s)
- Erick K Moen
- Ming Hsieh Department of Electrical Engineering - Electrophysics, University of Southern California, 920 Bloom Walk, SSC, 502 Los Angeles, CA, USA.
| | - Bennett L Ibey
- Bioeffects Division, 711 Human Performance Wing, Air Force Research Laboratory, 4141 Petroleum Rd., JBSA Fort Sam, Houston, TX 78234, USA
| | - Hope T Beier
- Bioeffects Division, 711 Human Performance Wing, Air Force Research Laboratory, 4141 Petroleum Rd., JBSA Fort Sam, Houston, TX 78234, USA
| | - Andrea M Armani
- Ming Hsieh Department of Electrical Engineering - Electrophysics, University of Southern California, 920 Bloom Walk, SSC, 502 Los Angeles, CA, USA
| |
Collapse
|
13
|
Nuriya M, Fukushima S, Momotake A, Shinotsuka T, Yasui M, Arai T. Multimodal two-photon imaging using a second harmonic generation-specific dye. Nat Commun 2016; 7:11557. [PMID: 27156702 PMCID: PMC4865818 DOI: 10.1038/ncomms11557] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 04/07/2016] [Indexed: 11/09/2022] Open
Abstract
Second harmonic generation (SHG) imaging can be used to visualize unique biological phenomena, but currently available dyes limit its application owing to the strong fluorescent signals that they generate together with SHG. Here we report the first non-fluorescent and membrane potential-sensitive SHG-active organic dye Ap3. Ap3 is photostable and generates SH signals at the plasma membrane with virtually no fluorescent signals, in sharp contrast to the previously used fluorescent dye FM4-64. When tested in neurons, Ap3-SHG shows linear membrane potential sensitivity and fast responses to action potentials, and also shows significantly reduced photodamage compared with FM4-64. The SHG-specific nature of Ap3 allows simultaneous and completely independent imaging of SHG signals and fluorescent signals from various reporter molecules, including markers of cellular organelles and intracellular calcium. Therefore, this SHG-specific dye enables true multimodal two-photon imaging in biological samples. Current dyes for second harmonic generation (SHG) imaging strongly fluoresce, limiting their application. Here the authors develop a SHG-specific dye, Ap3, that partitions into cell membranes, displays sensitivity to membrane potential and has virtually no fluorescence emission at SHG imaging wavelengths.
Collapse
Affiliation(s)
- Mutsuo Nuriya
- Department of Pharmacology School of Medicine, Keio University, 35 Shinanomachi, Tokyo 160-8582, Japan.,Graduate School of Environment and Information Sciences, Yokohama National University, Yokohama 240-8501, Japan
| | - Shun Fukushima
- Graduate School of Pure and Applied Sciences and Tsukuba Research Center for Interdisciplinary Materials Science (TIMS), University of Tsukuba, Tsukuba 305-8577, Japan
| | - Atsuya Momotake
- Graduate School of Pure and Applied Sciences and Tsukuba Research Center for Interdisciplinary Materials Science (TIMS), University of Tsukuba, Tsukuba 305-8577, Japan
| | - Takanori Shinotsuka
- Department of Pharmacology School of Medicine, Keio University, 35 Shinanomachi, Tokyo 160-8582, Japan
| | - Masato Yasui
- Department of Pharmacology School of Medicine, Keio University, 35 Shinanomachi, Tokyo 160-8582, Japan
| | - Tatsuo Arai
- Graduate School of Pure and Applied Sciences and Tsukuba Research Center for Interdisciplinary Materials Science (TIMS), University of Tsukuba, Tsukuba 305-8577, Japan
| |
Collapse
|