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Zheng B, Li M, Zhang T, Li B, Li Q, Saiding Q, Chen W, Guo M, Koo S, Ji X, Tao W. Functional modification of gut bacteria for disease diagnosis and treatment. MED 2024:S2666-6340(24)00249-6. [PMID: 38964334 DOI: 10.1016/j.medj.2024.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 11/15/2023] [Accepted: 06/12/2024] [Indexed: 07/06/2024]
Abstract
Intestinal bacteria help keep humans healthy by regulating lipid and glucose metabolism as well as the immunological and neurological systems. Oral treatment using intestinal bacteria is limited by the high acidity of stomach fluids and the immune system's attack on foreign bacteria. Scientists have created coatings and workarounds to overcome these limitations and improve bacterial therapy. These preparations have demonstrated promising outcomes, with advances in synthetic biology and optogenetics improving their focused colonization and controlled release. Engineering bacteria preparations have become a revolutionary therapeutic approach that converts intestinal bacteria into cellular factories for medicinal chemical synthesis. The present paper discusses various aspects of engineering bacteria preparations, including wrapping materials, biomedical uses, and future developments.
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Affiliation(s)
- Bin Zheng
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin 300072, China
| | - Mengyi Li
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin 300072, China
| | - Tiange Zhang
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin 300072, China
| | - Bowen Li
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin 300072, China
| | - Qiuya Li
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin 300072, China
| | - Qimanguli Saiding
- Center for Nanomedicine and Department of Anesthesiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Wei Chen
- Center for Nanomedicine and Department of Anesthesiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Mingming Guo
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin 300072, China
| | - Seyoung Koo
- Center for Nanomedicine and Department of Anesthesiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA; Department of Chemical and Molecular Engineering, Hanyang University ERICA, Ansan, Gyeonggi-do 15588, Republic of Korea.
| | - Xiaoyuan Ji
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin 300072, China.
| | - Wei Tao
- Center for Nanomedicine and Department of Anesthesiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
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Altahini S, Arnoux I, Stroh A. Optogenetics 2.0: challenges and solutions towards a quantitative probing of neural circuits. Biol Chem 2024; 405:43-54. [PMID: 37650383 DOI: 10.1515/hsz-2023-0194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 08/02/2023] [Indexed: 09/01/2023]
Abstract
To exploit the full potential of optogenetics, we need to titrate and tailor optogenetic methods to emulate naturalistic circuit function. For that, the following prerequisites need to be met: first, we need to target opsin expression not only to genetically defined neurons per se, but to specifically target a functional node. Second, we need to assess the scope of optogenetic modulation, i.e. the fraction of optogenetically modulated neurons. Third, we need to integrate optogenetic control in a closed loop setting. Fourth, we need to further safe and stable gene expression and light delivery to bring optogenetics to the clinics. Here, we review these concepts for the human and rodent brain.
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Affiliation(s)
- Saleh Altahini
- Leibniz Institute for Resilience Research, D-55122 Mainz, Germany
| | - Isabelle Arnoux
- Cerebral Physiopathology Laboratory, Center for Interdisciplinary Research in Biology, College de France, Centre national de la recherche scientifique, Institut national de la santé et de la recherche médicale, Université PSL, F-75005 Paris, France
| | - Albrecht Stroh
- Leibniz Institute for Resilience Research, D-55122 Mainz, Germany
- Institute of Pathophysiology, University Medical Center Mainz, D-55128 Mainz, Germany
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3
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Leng Y, Li X, Zheng F, Liu H, Wang C, Wang X, Liao Y, Liu J, Meng K, Yu J, Zhang J, Wang B, Tan Y, Liu M, Jia X, Li D, Li Y, Gu Z, Fan Y. Advances in In Vitro Models of Neuromuscular Junction: Focusing on Organ-on-a-Chip, Organoids, and Biohybrid Robotics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2211059. [PMID: 36934404 DOI: 10.1002/adma.202211059] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 02/18/2023] [Indexed: 06/18/2023]
Abstract
The neuromuscular junction (NMJ) is a peripheral synaptic connection between presynaptic motor neurons and postsynaptic skeletal muscle fibers that enables muscle contraction and voluntary motor movement. Many traumatic, neurodegenerative, and neuroimmunological diseases are classically believed to mainly affect either the neuronal or the muscle side of the NMJ, and treatment options are lacking. Recent advances in novel techniques have helped develop in vitro physiological and pathophysiological models of the NMJ as well as enable precise control and evaluation of its functions. This paper reviews the recent developments in in vitro NMJ models with 2D or 3D cultures, from organ-on-a-chip and organoids to biohybrid robotics. Related derivative techniques are introduced for functional analysis of the NMJ, such as the patch-clamp technique, microelectrode arrays, calcium imaging, and stimulus methods, particularly optogenetic-mediated light stimulation, microelectrode-mediated electrical stimulation, and biochemical stimulation. Finally, the applications of the in vitro NMJ models as disease models or for drug screening related to suitable neuromuscular diseases are summarized and their future development trends and challenges are discussed.
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Affiliation(s)
- Yubing Leng
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Xiaorui Li
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Fuyin Zheng
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Hui Liu
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Chunyan Wang
- State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, 100094, China
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China
| | - Xudong Wang
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Yulong Liao
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Jiangyue Liu
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Kaiqi Meng
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Jiaheng Yu
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Jingyi Zhang
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Binyu Wang
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Yingjun Tan
- State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, 100094, China
| | - Meili Liu
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Xiaoling Jia
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Deyu Li
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Yinghui Li
- State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, 100094, China
| | - Zhongze Gu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China
| | - Yubo Fan
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
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4
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Vurro V, Shani K, Ardoña HAM, Zimmerman JF, Sesti V, Lee KY, Jin Q, Bertarelli C, Parker KK, Lanzani G. Light-triggered cardiac microphysiological model. APL Bioeng 2023; 7:026108. [PMID: 37234844 PMCID: PMC10208677 DOI: 10.1063/5.0143409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 04/24/2023] [Indexed: 05/28/2023] Open
Abstract
Light is recognized as an accurate and noninvasive tool for stimulating excitable cells. Here, we report on a non-genetic approach based on organic molecular phototransducers that allows wiring- and electrode-free tissue modulation. As a proof of concept, we show photostimulation of an in vitro cardiac microphysiological model mediated by an amphiphilic azobenzene compound that preferentially dwells in the cell membrane. Exploiting this optical based stimulation technology could be a disruptive approach for highly resolved cardiac tissue stimulation.
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Affiliation(s)
- V. Vurro
- Center for Nanoscience and Technology, Istituto Italiano di Teconologia, Milano, 20133 Italy
| | - K. Shani
- Disease Biophysics Group, John A. Paulson School of Engineering and Applied Science, Harvard University, Boston, Massachusetts 02134, USA
| | | | - J. F. Zimmerman
- Disease Biophysics Group, John A. Paulson School of Engineering and Applied Science, Harvard University, Boston, Massachusetts 02134, USA
| | | | | | - Q. Jin
- Disease Biophysics Group, John A. Paulson School of Engineering and Applied Science, Harvard University, Boston, Massachusetts 02134, USA
| | | | - K. K. Parker
- Disease Biophysics Group, John A. Paulson School of Engineering and Applied Science, Harvard University, Boston, Massachusetts 02134, USA
| | - G. Lanzani
- Author to whom correspondence should be addressed:
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5
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Optical modulation of excitation-contraction coupling in human-induced pluripotent stem cell-derived cardiomyocytes. iScience 2023; 26:106121. [PMID: 36879812 PMCID: PMC9984557 DOI: 10.1016/j.isci.2023.106121] [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: 07/28/2022] [Revised: 01/08/2023] [Accepted: 01/30/2023] [Indexed: 02/05/2023] Open
Abstract
Non-genetic photostimulation is a novel and rapidly growing multidisciplinary field that aims to induce light-sensitivity in living systems by exploiting exogeneous phototransducers. Here, we propose an intramembrane photoswitch, based on an azobenzene derivative (Ziapin2), for optical pacing of human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). The light-mediated stimulation process has been studied by applying several techniques to detect the effect on the cell properties. In particular, we recorded changes in membrane capacitance, in membrane potential (Vm), and modulation of intracellular Ca2+ dynamics. Finally, cell contractility was analyzed using a custom MATLAB algorithm. Photostimulation of intramembrane Ziapin2 causes a transient Vm hyperpolarization followed by a delayed depolarization and action potential firing. The observed initial electrical modulation nicely correlates with changes in Ca2+ dynamics and contraction rate. This work represents the proof of principle that Ziapin2 can modulate electrical activity and contractility in hiPSC-CMs, opening up a future development in cardiac physiology.
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Pedraza-González L, Barneschi L, Marszałek M, Padula D, De Vico L, Olivucci M. Automated QM/MM Screening of Rhodopsin Variants with Enhanced Fluorescence. J Chem Theory Comput 2023; 19:293-310. [PMID: 36516450 DOI: 10.1021/acs.jctc.2c00928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We present a computational protocol for the fast and automated screening of excited-state hybrid quantum mechanics/molecular mechanics (QM/MM) models of rhodopsins to be used as fluorescent probes based on the automatic rhodopsin modeling protocol (a-ARM). Such "a-ARM fluorescence screening protocol" is implemented through a general Python-based driver, PyARM, that is also proposed here. The implementation and performance of the protocol are benchmarked using different sets of rhodopsin variants whose absorption and, more relevantly, emission spectra have been experimentally measured. We show that, despite important limitations that make unsafe to use it as a black-box tool, the protocol reproduces the observed trends in fluorescence and it is capable of selecting novel potentially fluorescent rhodopsins. We also show that the protocol can be used in mechanistic investigations to discern fluorescence enhancement effects associated with a near degeneracy of the S1/S2 states or, alternatively, with a barrier generated via coupling of the S0/S1 wave functions.
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Affiliation(s)
- Laura Pedraza-González
- Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via A. Moro 2, I-53100 Siena, Italy
| | - Leonardo Barneschi
- Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via A. Moro 2, I-53100 Siena, Italy
| | - Michał Marszałek
- Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via A. Moro 2, I-53100 Siena, Italy.,Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiaǹskiego 27, 50-370 Wrocław, Poland
| | - Daniele Padula
- Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via A. Moro 2, I-53100 Siena, Italy
| | - Luca De Vico
- Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via A. Moro 2, I-53100 Siena, Italy
| | - Massimo Olivucci
- Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via A. Moro 2, I-53100 Siena, Italy.,Department of Chemistry, Bowling Green State University, Bowling Green, Ohio 43403, United States
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Jones JJ, Huang S, Hedrich R, Geilfus CM, Roelfsema MRG. The green light gap: a window of opportunity for optogenetic control of stomatal movement. THE NEW PHYTOLOGIST 2022; 236:1237-1244. [PMID: 36052708 DOI: 10.1111/nph.18451] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 08/17/2022] [Indexed: 06/15/2023]
Abstract
Green plants are equipped with photoreceptors that are capable of sensing radiation in the ultraviolet-to-blue and the red-to-far-red parts of the light spectrum. However, plant cells are not particularly sensitive to green light (GL), and light which lies within this part of the spectrum does not efficiently trigger the opening of stomatal pores. Here, we discuss the current knowledge of stomatal responses to light, which are either provoked via photosynthetically active radiation or by specific blue light (BL) signaling pathways. The limited impact of GL on stomatal movements provides a unique option to use this light quality to control optogenetic tools. Recently, several of these tools have been optimized for use in plant biological research, either to control gene expression, or to provoke ion fluxes. Initial studies with the BL-activated potassium channel BLINK1 showed that this tool can speed up stomatal movements. Moreover, the GL-sensitive anion channel GtACR1 can induce stomatal closure, even at conditions that provoke stomatal opening in wild-type plants. Given that crop plants in controlled-environment agriculture and horticulture are often cultivated with artificial light sources (i.e. a combination of blue and red light from light-emitting diodes), GL signals can be used as a remote-control signal that controls stomatal transpiration and water consumption.
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Affiliation(s)
- Jeffrey J Jones
- Division of Controlled Environment Horticulture, Faculty of Life Sciences, Albrecht Daniel Thaer-Institute of Agricultural and Horticultural Sciences, Humboldt-University of Berlin, Berlin, 14195, Germany
| | - Shouguang Huang
- Molecular Plant Physiology and Biophysics, Biocenter, University of Würzburg, 97082, Würzburg, Germany
| | - Rainer Hedrich
- Molecular Plant Physiology and Biophysics, Biocenter, University of Würzburg, 97082, Würzburg, Germany
| | - Christoph-Martin Geilfus
- Division of Controlled Environment Horticulture, Faculty of Life Sciences, Albrecht Daniel Thaer-Institute of Agricultural and Horticultural Sciences, Humboldt-University of Berlin, Berlin, 14195, Germany
- Department of Soil Science and Plant Nutrition, Hochschule Geisenheim University, 65366, Geisenheim, Germany
| | - M Rob G Roelfsema
- Molecular Plant Physiology and Biophysics, Biocenter, University of Würzburg, 97082, Würzburg, Germany
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Optogenetically Engineered Neurons Differentiated from Human SH-SY5Y Cells Survived and Expressed ChR2 in 3D Hydrogel. Biomedicines 2022; 10:biomedicines10071534. [PMID: 35884839 PMCID: PMC9313127 DOI: 10.3390/biomedicines10071534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 06/20/2022] [Accepted: 06/25/2022] [Indexed: 11/25/2022] Open
Abstract
The cases of brain degenerative disease will rise as the human population ages. Current treatments have a transient effect and lack an investigative system that is physiologically relevant for testing. There is evidence suggesting optogenetic stimulation is a potential strategy; however, an in vitro disease and optogenetic model requires a three-dimensional microenvironment. Alginate is a promising material for tissue and optogenetic engineering. Although it is bioinert, alginate hydrogel is transparent and therefore allows optical penetration for stimulation. In this study, alginate was functionalized with arginine-glycine-aspartate acid (RGD) to serve as a 3D platform for encapsulation of human SH-SY5Y cells, which were optogenetically modified and characterized. The RGD-alginate hydrogels were tested for swelling and degradation. Prior to encapsulation, the cells were assessed for neuronal expression and optical-stimulation response. The results showed that RGD-alginate possessed a consistent swelling ratio of 18% on day 7, and degradation remained between 3.7−5% throughout 14 days. Optogenetically modified SH-SY5Y cells were highly viable (>85%) after lentiviral transduction and neuronal differentiation. The cells demonstrated properties of functional neurons, developing beta III tubulin (TuJ1)-positive long neurites, forming neural networks, and expressing vGlut2. Action potentials were produced upon optical stimulation. The neurons derived from human SH-SY5Y cells were successfully genetically modified and encapsulated; they survived and expressed ChR2 in an RGD-alginate hydrogel system.
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Bergs A, Henss T, Glock C, Nagpal J, Gottschalk A. Microbial Rhodopsin Optogenetic Tools: Application for Analyses of Synaptic Transmission and of Neuronal Network Activity in Behavior. Methods Mol Biol 2022; 2468:89-115. [PMID: 35320562 DOI: 10.1007/978-1-0716-2181-3_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Over the past 15 years, optogenetic methods have revolutionized neuroscientific and cell biological research, also in the nematode Caenorhabditis elegans. In this chapter, we give an update about current optogenetic tools and methods to address neuronal activity and inhibition, as well as second messenger signaling, based on microbial rhodopsins. We address channelrhodopsins and variants thereof, which conduct cations or anions, for depolarization and hyperpolarization of the membrane potential. Also, we cover ion pumping rhodopsins, like halorhodopsin, Mac, and Arch. A recent addition to rhodopsin-based optogenetics is voltage imaging tools that allow fluorescent readout of membrane voltage (directly, via fluorescence of the rhodopsin chromophore retinal, or indirectly, via electrochromic FRET). Last, we report on a new addition to the optogenetic toolbox, which is rhodopsin guanylyl cyclases, as well as mutated variants with specificity for cyclic AMP. These can be used to regulate intracellular levels of cGMP and cAMP, which are important second messengers in sensory and other neurons. We further show how they can be combined with cyclic nucleotide-gated channels in two-component optogenetics, for depolarization or hyperpolarization of membrane potential. For all tools, we present protocols for straightforward experimentation to address neuronal activation and inhibition, particularly at the neuromuscular junction, and for combined optogenetic actuation and Ca2+ imaging. We also provide protocols for usage of rhodopsin guanylyl and adenylyl cyclases. Finally, we list a number of points to consider when designing and conducting rhodopsin-based optogenetic experiments.
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Affiliation(s)
- Amelie Bergs
- Buchmann Institute for Molecular Life Sciences, Goethe University, Frankfurt, Germany
- Institute of Biophysical Chemistry, Goethe University, Frankfurt, Germany
| | - Thilo Henss
- Buchmann Institute for Molecular Life Sciences, Goethe University, Frankfurt, Germany
- Institute of Biophysical Chemistry, Goethe University, Frankfurt, Germany
| | - Caspar Glock
- Buchmann Institute for Molecular Life Sciences, Goethe University, Frankfurt, Germany
- Institute of Biophysical Chemistry, Goethe University, Frankfurt, Germany
- Max-Planck-Institute for Brain Research, Frankfurt, Germany
| | - Jatin Nagpal
- Buchmann Institute for Molecular Life Sciences, Goethe University, Frankfurt, Germany
- Institute of Biophysical Chemistry, Goethe University, Frankfurt, Germany
- APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Alexander Gottschalk
- Buchmann Institute for Molecular Life Sciences, Goethe University, Frankfurt, Germany.
- Institute of Biophysical Chemistry, Goethe University, Frankfurt, Germany.
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Kolesov DV, Sokolinskaya EL, Lukyanov KA, Bogdanov AM. Molecular Tools for Targeted Control of Nerve Cell Electrical Activity. Part I. Acta Naturae 2021; 13:52-64. [PMID: 34707897 PMCID: PMC8526180 DOI: 10.32607/actanaturae.11414] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 05/14/2021] [Indexed: 12/18/2022] Open
Abstract
In modern life sciences, the issue of a specific, exogenously directed
manipulation of a cell’s biochemistry is a highly topical one. In the
case of electrically excitable cells, the aim of the manipulation is to control
the cells’ electrical activity, with the result being either excitation
with subsequent generation of an action potential or inhibition and suppression
of the excitatory currents. The techniques of electrical activity stimulation
are of particular significance in tackling the most challenging basic problem:
figuring out how the nervous system of higher multicellular organisms
functions. At this juncture, when neuroscience is gradually abandoning the
reductionist approach in favor of the direct investigation of complex neuronal
systems, minimally invasive methods for brain tissue stimulation are becoming
the basic element in the toolbox of those involved in the field. In this
review, we describe three approaches that are based on the delivery of
exogenous, genetically encoded molecules sensitive to external stimuli into the
nervous tissue. These approaches include optogenetics (Part I) as well as
chemogenetics and thermogenetics (Part II), which are significantly different
not only in the nature of the stimuli and structure of the appropriate effector
proteins, but also in the details of experimental applications. The latter
circumstance is an indication that these are rather complementary than
competing techniques.
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Affiliation(s)
- D. V. Kolesov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997 Russia
| | - E. L. Sokolinskaya
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997 Russia
| | - K. A. Lukyanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997 Russia
| | - A. M. Bogdanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997 Russia
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11
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Bartley AF, Fischer M, Bagley ME, Barnes JA, Burdette MK, Cannon KE, Bolding MS, Foulger SH, McMahon LL, Weick JP, Dobrunz LE. Feasibility of cerium-doped LSO particles as a scintillator for x-ray induced optogenetics. J Neural Eng 2021; 18:10.1088/1741-2552/abef89. [PMID: 33730704 PMCID: PMC8656171 DOI: 10.1088/1741-2552/abef89] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 03/17/2021] [Indexed: 11/11/2022]
Abstract
Objective.Non-invasive light delivery into the brain is needed forin vivooptogenetics to avoid physical damage. An innovative strategy could employ x-ray activation of radioluminescent particles (RLPs) to emit localized light. However, modulation of neuronal or synaptic function by x-ray induced radioluminescence from RLPs has not yet been demonstrated.Approach.Molecular and electrophysiological approaches were used to determine if x-ray dependent radioluminescence emitted from RLPs can activate light sensitive proteins. RLPs composed of cerium doped lutetium oxyorthosilicate (LSO:Ce), an inorganic scintillator that emits blue light, were used as they are biocompatible with neuronal function and synaptic transmission.Main results.We show that 30 min of x-ray exposure at a rate of 0.042 Gy s-1caused no change in the strength of basal glutamatergic transmission during extracellular field recordings in mouse hippocampal slices. Additionally, long-term potentiation, a robust measure of synaptic integrity, was induced after x-ray exposure and expressed at a magnitude not different from control conditions (absence of x-rays). We found that x-ray stimulation of RLPs elevated cAMP levels in HEK293T cells expressing OptoXR, a chimeric opsin receptor that combines the extracellular light-sensitive domain of rhodopsin with an intracellular second messenger signaling cascade. This demonstrates that x-ray radioluminescence from LSO:Ce particles can activate OptoXR. Next, we tested whether x-ray activation of the RLPs can enhance synaptic activity in whole-cell recordings from hippocampal neurons expressing channelrhodopsin-2, both in cell culture and acute hippocampal slices. Importantly, x-ray radioluminescence caused an increase in the frequency of spontaneous excitatory postsynaptic currents in both systems, indicating activation of channelrhodopsin-2 and excitation of neurons.Significance.Together, our results show that x-ray activation of LSO:Ce particles can heighten cellular and synaptic function. The combination of LSO:Ce inorganic scintillators and x-rays is therefore a viable method for optogenetics as an alternative to more invasive light delivery methods.
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Affiliation(s)
- Aundrea F Bartley
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, United States of America
- Civitan International Research Center, University of Alabama at Birmingham, Birmingham, AL, United States of America
- Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, United States of America
- Comprehensive Neuroscience Center, University of Alabama at Birmingham, Birmingham, AL, United States of America
| | - Máté Fischer
- Department of Neurosciences, University of New Mexico-Health Sciences Center, Albuquerque, NM, United States of America
| | - Micah E Bagley
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, United States of America
| | - Justin A Barnes
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, United States of America
| | - Mary K Burdette
- Department of Materials Science and Engineering, Clemson University, Anderson, SC, United States of America
| | - Kelli E Cannon
- Department of Vision Science, University of Alabama at Birmingham, Birmingham, AL, United States of America
| | - Mark S Bolding
- Department of Radiology, University of Alabama at Birmingham, Birmingham, AL, United States of America
| | - Stephen H Foulger
- Department of Materials Science and Engineering, Clemson University, Anderson, SC, United States of America
- Center for Optical Materials Science and Engineering Technologies, Clemson University, Anderson, SC, United States of America
- Department of Bioengineering, Clemson University, Clemson, SC, United States of America
| | - Lori L McMahon
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, United States of America
- Civitan International Research Center, University of Alabama at Birmingham, Birmingham, AL, United States of America
- Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, United States of America
- Comprehensive Neuroscience Center, University of Alabama at Birmingham, Birmingham, AL, United States of America
| | - Jason P Weick
- Department of Neurosciences, University of New Mexico-Health Sciences Center, Albuquerque, NM, United States of America
| | - Lynn E Dobrunz
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, United States of America
- Civitan International Research Center, University of Alabama at Birmingham, Birmingham, AL, United States of America
- Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, United States of America
- Comprehensive Neuroscience Center, University of Alabama at Birmingham, Birmingham, AL, United States of America
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12
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Salmina AB, Gorina YV, Erofeev AI, Balaban PM, Bezprozvanny IB, Vlasova OL. Optogenetic and chemogenetic modulation of astroglial secretory phenotype. Rev Neurosci 2021; 32:459-479. [PMID: 33550788 DOI: 10.1515/revneuro-2020-0119] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Accepted: 11/28/2020] [Indexed: 12/20/2022]
Abstract
Astrocytes play a major role in brain function and alterations in astrocyte function that contribute to the pathogenesis of many brain disorders. The astrocytes are attractive cellular targets for neuroprotection and brain tissue regeneration. Development of novel approaches to monitor and to control astroglial function is of great importance for further progress in basic neurobiology and in clinical neurology, as well as psychiatry. Recently developed advanced optogenetic and chemogenetic techniques enable precise stimulation of astrocytes in vitro and in vivo, which can be achieved by the expression of light-sensitive channels and receptors, or by expression of receptors exclusively activated by designer drugs. Optogenetic stimulation of astrocytes leads to dramatic changes in intracellular calcium concentrations and causes the release of gliotransmitters. Optogenetic and chemogenetic protocols for astrocyte activation aid in extracting novel information regarding the function of brain's neurovascular unit. This review summarizes current data obtained by this approach and discusses a potential mechanistic connection between astrocyte stimulation and changes in brain physiology.
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Affiliation(s)
- Alla B Salmina
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia
- Research Institute of Molecular Medicine and Pathobiochemistry, Prof. V.F. Voino-Yasenetsky Krasnoyarsk State Medical University, Krasnoyarsk, Russia
| | - Yana V Gorina
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia
- Research Institute of Molecular Medicine and Pathobiochemistry, Prof. V.F. Voino-Yasenetsky Krasnoyarsk State Medical University, Krasnoyarsk, Russia
| | - Alexander I Erofeev
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia
| | - Pavel M Balaban
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia
- Laboratory of Cellular Neurobiology of Learning, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia
| | - Ilya B Bezprozvanny
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia
- Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
| | - Olga L Vlasova
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia
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13
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Seo DO, Motard LE, Bruchas MR. Contemporary strategies for dissecting the neuronal basis of neurodevelopmental disorders. Neurobiol Learn Mem 2019; 165:106835. [PMID: 29550367 PMCID: PMC6138573 DOI: 10.1016/j.nlm.2018.03.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 02/22/2018] [Accepted: 03/13/2018] [Indexed: 01/07/2023]
Abstract
Great efforts in clinical and basic research have shown progress in understanding the neurobiological mechanisms of neurodevelopmental disorders, such as autism, schizophrenia, and attention-deficit hyperactive disorders. Literature on this field have suggested that these disorders are affected by the complex interaction of genetic, biological, psychosocial and environmental risk factors. However, this complexity of interplaying risk factors during neurodevelopment has prevented a complete understanding of the causes of those neuropsychiatric symptoms. Recently, with advances in modern high-resolution neuroscience methods, the neural circuitry analysis approach has provided new solutions for understanding the causal relationship between dysfunction of a neural circuit and behavioral alteration in neurodevelopmental disorders. In this review we will discuss recent progress in developing novel optogenetic and chemogenetic strategies to investigate neurodevelopmental disorders.
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Affiliation(s)
- Dong-Oh Seo
- Departmentof Anesthesiology, Division of Basic Research, Washington University School of Medicine, St. Louis, MO 63110, United States
| | - Laura E Motard
- Departmentof Anesthesiology, Division of Basic Research, Washington University School of Medicine, St. Louis, MO 63110, United States; Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, United States
| | - Michael R Bruchas
- Departmentof Anesthesiology, Division of Basic Research, Washington University School of Medicine, St. Louis, MO 63110, United States; Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, United States; Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, United States; Division of Biology and Biomedical Sciences, Washington University School of Medicine, St. Louis, MO 63110, United States; Washington University Pain Center, Washington University School of Medicine, St. Louis, MO 63110, United States.
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14
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Bartley AF, Abiraman K, Stewart LT, Hossain MI, Gahan DM, Kamath AV, Burdette MK, Andrabe S, Foulger SH, McMahon LL, Dobrunz LE. LSO:Ce Inorganic Scintillators Are Biocompatible With Neuronal and Circuit Function. Front Synaptic Neurosci 2019; 11:24. [PMID: 31551750 PMCID: PMC6733890 DOI: 10.3389/fnsyn.2019.00024] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 08/06/2019] [Indexed: 12/19/2022] Open
Abstract
Optogenetics is widely used in neuroscience to control neural circuits. However, non-invasive methods for light delivery in brain are needed to avoid physical damage caused by current methods. One potential strategy could employ x-ray activation of radioluminescent particles (RPLs), enabling localized light generation within the brain. RPLs composed of inorganic scintillators can emit light at various wavelengths depending upon composition. Cerium doped lutetium oxyorthosilicate (LSO:Ce), an inorganic scintillator that emits blue light in response to x-ray or ultraviolet (UV) stimulation, could potentially be used to control neural circuits through activation of channelrhodopsin-2 (ChR2), a light-gated cation channel. Whether inorganic scintillators themselves negatively impact neuronal processes and synaptic function is unknown, and was investigated here using cellular, molecular, and electrophysiological approaches. As proof of principle, we applied UV stimulation to 4 μm LSO:Ce particles during whole-cell recording of CA1 pyramidal cells in acute hippocampal slices from mice that expressed ChR2 in glutamatergic neurons. We observed an increase in frequency and amplitude of spontaneous excitatory postsynaptic currents (sEPSCs), indicating activation of ChR2 and excitation of neurons. Importantly, LSO:Ce particles did not affect survival of primary mouse cortical neurons, even after 24 h of exposure. In extracellular dendritic field potential recordings, no change in the strength of basal glutamatergic transmission was observed during exposure to LSO:Ce microparticles. However, the amplitude of the fiber volley was slightly reduced with high stimulation. Additionally, there was a slight decrease in the frequency of sEPSCs in whole-cell voltage-clamp recordings from CA1 pyramidal cells, with no change in current amplitudes. The amplitude and frequency of spontaneous inhibitory postsynaptic currents were unchanged. Finally, long term potentiation (LTP), a synaptic modification believed to underlie learning and memory and a robust measure of synaptic integrity, was successfully induced, although the magnitude was slightly reduced. Together, these results show LSO:Ce particles are biocompatible even though there are modest effects on baseline synaptic function and long-term synaptic plasticity. Importantly, we show that light emitted from LSO:Ce particles is able to activate ChR2 and modify synaptic function. Therefore, LSO:Ce inorganic scintillators are potentially viable for use as a new light delivery system for optogenetics.
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Affiliation(s)
- Aundrea F. Bartley
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, United States
- Civitan International Research Center, University of Alabama at Birmingham, Birmingham, AL, United States
- Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, United States
- Comprehensive Neuroscience Center, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Kavitha Abiraman
- Comprehensive Neuroscience Center, University of Alabama at Birmingham, Birmingham, AL, United States
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Luke T. Stewart
- Comprehensive Neuroscience Center, University of Alabama at Birmingham, Birmingham, AL, United States
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Mohammed Iqbal Hossain
- Department of Pharmacology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - David M. Gahan
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Abhishek V. Kamath
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Mary K. Burdette
- Department of Materials Science and Engineering, Clemson University, Anderson, SC, United States
| | - Shaida Andrabe
- Department of Pharmacology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Stephen H. Foulger
- Department of Materials Science and Engineering, Clemson University, Anderson, SC, United States
- Center for Optical Materials Science and Engineering Technologies, Clemson University, Anderson, SC, United States
- Department of Bioengineering, Clemson University, Clemson, SC, United States
| | - Lori L. McMahon
- Civitan International Research Center, University of Alabama at Birmingham, Birmingham, AL, United States
- Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, United States
- Comprehensive Neuroscience Center, University of Alabama at Birmingham, Birmingham, AL, United States
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Lynn E. Dobrunz
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, United States
- Civitan International Research Center, University of Alabama at Birmingham, Birmingham, AL, United States
- Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, United States
- Comprehensive Neuroscience Center, University of Alabama at Birmingham, Birmingham, AL, United States
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15
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Au SLC, Chen FYB, Budgett DM, Malpas SC, Guild SJ, McCormick D. Injection Molded Liquid Crystal Polymer Package for Chronic Active Implantable Devices With Application to an Optogenetic Stimulator. IEEE Trans Biomed Eng 2019; 67:1357-1365. [PMID: 31442965 DOI: 10.1109/tbme.2019.2936577] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Implanted electronics require protection from the body's fluids to avoid moisture induced failure. This study presents an injection molded liquid crystal polymer (LCP) package to protect active implantable devices for chronic applications, such as in optogenetic research. The technology is applied and assessed through a custom package for a fully implantable optogenetic stimulation system, built on a versatile telemetry system that can incorporate additional stimulating and recording channels. An adapted quasi-steady state model predicts the lifetime of an enclosure, where the definition of the lifetime is the time before the internal relative humidity (RH) reaches a time constant, or 63%RH, a conservative limit to minimize the risk of corrosion. The lifetime of the LCP optogenetic device is 94 days, and can be extended to 326 days with the inclusion of 5% w/v silica gel desiccant. Samples of the LCP optogenetic device containing humidity sensors testing in saline at 38 °C support the RH change predictions. Desiccants inside the implant enclosure can store permeating moisture and prolong the life expectancy of LCP-based implants to years or decades. The results of this study demonstrates the feasibility of providing reliable protection for chronic optogenetic implants, and the technology can be transferred to other applications as an easily-manufactured, cost-effective, radiofrequency compatible alternative to hermetic packaging for chronic studies.
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16
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Ernst P, Xu N, Qu J, Chen H, Goldberg MS, Darley-Usmar V, Zhang JJ, O'Rourke B, Liu X, Zhou L. Precisely Control Mitochondria with Light to Manipulate Cell Fate Decision. Biophys J 2019; 117:631-645. [PMID: 31400914 DOI: 10.1016/j.bpj.2019.06.038] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 05/13/2019] [Accepted: 06/17/2019] [Indexed: 12/31/2022] Open
Abstract
Mitochondrial dysfunction has been implicated in many pathological conditions and diseases. The normal functioning of mitochondria relies on maintaining the inner mitochondrial membrane potential (also known as ΔΨm) that is essential for ATP synthesis, Ca2+ homeostasis, redox balance, and regulation of other key signaling pathways such as mitophagy and apoptosis. However, the detailed mechanisms by which ΔΨm regulates cellular function remain incompletely understood, partially because of the difficulty of manipulating ΔΨm with spatiotemporal resolution, reversibility, or cell type specificity. To address this need, we have developed a next generation optogenetic-based technique for controllable mitochondrial depolarization with light. We demonstrate successful targeting of the heterologous channelrhodopsin-2 fusion protein to the inner mitochondrial membrane and formation of functional cationic channels capable of light-induced selective ΔΨm depolarization and mitochondrial autophagy. Importantly, we for the first time, to our knowledge, show that optogenetic-mediated mitochondrial depolarization can be well controlled to differentially influence the fate of cells expressing mitochondrial channelrhodopsin-2; whereas sustained moderate light illumination induces substantial apoptotic cell death, transient mild light illumination elicits cytoprotection via mitochondrial preconditioning. Finally, we show that Parkin overexpression exacerbates, instead of ameliorating, mitochondrial depolarization-mediated cell death in HeLa cells. In summary, we provide evidence that the described mitochondrial-targeted optogenetics may have a broad application for studying the role of mitochondria in regulating cell function and fate decision.
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Affiliation(s)
- Patrick Ernst
- Departments of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama; Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Ningning Xu
- Departments of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama
| | - Jing Qu
- Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Herbert Chen
- Surgery, University of Alabama at Birmingham, Birmingham, Alabama
| | | | | | - Jianyi J Zhang
- Departments of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama
| | - Brian O'Rourke
- Division of Cardiology, Department of Medicine, The Johns Hopkins University, Baltimore, Maryland
| | - Xiaoguang Liu
- Departments of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama
| | - Lufang Zhou
- Departments of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama; Medicine, University of Alabama at Birmingham, Birmingham, Alabama.
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17
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Pedraza-González L, De Vico L, del Carmen Marín M, Fanelli F, Olivucci M. a-ARM: Automatic Rhodopsin Modeling with Chromophore Cavity Generation, Ionization State Selection, and External Counterion Placement. J Chem Theory Comput 2019; 15:3134-3152. [PMID: 30916955 PMCID: PMC7141608 DOI: 10.1021/acs.jctc.9b00061] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The Automatic Rhodopsin Modeling (ARM) protocol has recently been proposed as a tool for the fast and parallel generation of basic hybrid quantum mechanics/molecular mechanics (QM/MM) models of wild type and mutant rhodopsins. However, in its present version, input preparation requires a few hours long user's manipulation of the template protein structure, which also impairs the reproducibility of the generated models. This limitation, which makes model building semiautomatic rather than fully automatic, comprises four tasks: definition of the retinal chromophore cavity, assignment of protonation states of the ionizable residues, neutralization of the protein with external counterions, and finally congruous generation of single or multiple mutations. In this work, we show that the automation of the original ARM protocol can be extended to a level suitable for performing the above tasks without user's manipulation and with an input preparation time of minutes. The new protocol, called a-ARM, delivers fully reproducible (i.e., user independent) rhodopsin QM/MM models as well as an improved model quality. More specifically, we show that the trend in vertical excitation energies observed for a set of 25 wild type and 14 mutant rhodopsins is predicted by the new protocol better than when using the original. Such an agreement is reflected by an estimated (relative to the probed set) trend deviation of 0.7 ± 0.5 kcal mol-1 (0.03 ± 0.02 eV) and mean absolute error of 1.0 kcal mol-1 (0.04 eV).
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Affiliation(s)
- Laura Pedraza-González
- Department of Biotechnologies, Chemistry and Pharmacy, Università degli Studi di Siena, via A. Moro 2, I-53100 Siena, Italy
| | - Luca De Vico
- Department of Biotechnologies, Chemistry and Pharmacy, Università degli Studi di Siena, via A. Moro 2, I-53100 Siena, Italy
| | - María del Carmen Marín
- Department of Biotechnologies, Chemistry and Pharmacy, Università degli Studi di Siena, via A. Moro 2, I-53100 Siena, Italy
| | - Francesca Fanelli
- Department of Life Sciences, Center for Neuroscience and Neurotechnology, Università degli Studi di Modena e Reggio Emilia, I-41125 Modena, Italy
| | - Massimo Olivucci
- Department of Biotechnologies, Chemistry and Pharmacy, Università degli Studi di Siena, via A. Moro 2, I-53100 Siena, Italy
- Department of Chemistry, Bowling Green State University, Bowling Green, Ohio 43403, United States
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18
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Wang Z, Hu M, Ai X, Zhang Z, Xing B. Near-Infrared Manipulation of Membrane Ion Channels via Upconversion Optogenetics. ADVANCED BIOSYSTEMS 2019; 3:e1800233. [PMID: 32627341 DOI: 10.1002/adbi.201800233] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Revised: 09/27/2018] [Indexed: 12/21/2022]
Abstract
Membrane ion channels are ultimately responsible for the propagation and integration of electrical signals in the nervous, muscular, and other systems. Their activation or malfunctioning plays a significant role in physiological and pathophysiological processes. Using optogenetics to dynamically and spatiotemporally control ion channels has recently attracted considerable attention. However, most of the established optogenetic tools (e.g., channelrhodopsins, ChRs) for optical manipulations, are mainly stimulated by UV or visible light, which raises the concerns of potential photodamage, limited tissue penetration, and high-invasive implantation of optical fiber devices. Near-infrared (NIR) upconversion nanoparticle (UCNP)-mediated optogenetic systems provide great opportunities for overcoming the problems encountered in the manipulation of ion channels in deep tissues. Hence, this review focuses on the recent advances in NIR regulation of membrane ion channels via upconversion optogenetics in biomedical research. The engineering and applications of upconversion optogenetic systems by the incorporation multiple emissive UCNPs into various light-gated ChRs/ligands are first elaborated, followed by a detailed discussion of the technical improvements for more precise and efficient control of membrane channels. Finally, the future perspectives for refining and advancing NIR-mediated upconversion optogenetics into in vivo even in clinical applications are proposed.
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Affiliation(s)
- Zhimin Wang
- Division of Chemistry and Biological Chemistry, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore
| | - Ming Hu
- Division of Chemistry and Biological Chemistry, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore
| | - Xiangzhao Ai
- Division of Chemistry and Biological Chemistry, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore
| | - Zhijun Zhang
- Division of Chemistry and Biological Chemistry, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore
| | - Bengang Xing
- Division of Chemistry and Biological Chemistry, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore
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19
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Luchkina NV, Bolshakov VY. Diminishing fear: Optogenetic approach toward understanding neural circuits of fear control. Pharmacol Biochem Behav 2018; 174:64-79. [PMID: 28502746 PMCID: PMC5681900 DOI: 10.1016/j.pbb.2017.05.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 04/13/2017] [Accepted: 05/10/2017] [Indexed: 02/05/2023]
Abstract
Understanding complex behavioral processes, both learned and innate, requires detailed characterization of the principles governing signal flow in corresponding neural circuits. Previous studies were hampered by the lack of appropriate tools needed to address the complexities of behavior-driving micro- and macrocircuits. The development and implementation of optogenetic methodologies revolutionized the field of behavioral neuroscience, allowing precise spatiotemporal control of specific, genetically defined neuronal populations and their functional connectivity both in vivo and ex vivo, thus providing unprecedented insights into the cellular and network-level mechanisms contributing to behavior. Here, we review recent pioneering advances in behavioral studies with optogenetic tools, focusing on mechanisms of fear-related behavioral processes with an emphasis on approaches which could be used to suppress fear when it is pathologically expressed. We also discuss limitations of these methodologies as well as review new technological developments which could be used in future mechanistic studies of fear behavior.
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Affiliation(s)
- Natalia V Luchkina
- Department of Psychiatry, McLean Hospital, Harvard Medical School, Belmont, MA 02478, USA.
| | - Vadim Y Bolshakov
- Department of Psychiatry, McLean Hospital, Harvard Medical School, Belmont, MA 02478, USA.
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20
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Jiang W, Rajguru SM. Eye Movements Evoked by Pulsed Infrared Radiation of the Rat Vestibular System. Ann Biomed Eng 2018; 46:1406-1418. [PMID: 29845411 PMCID: PMC6095805 DOI: 10.1007/s10439-018-2059-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 05/24/2018] [Indexed: 10/16/2022]
Abstract
Light at infrared wavelengths has been demonstrated to modulate the pattern of neural signals transmitted from the angular motion sensing semicircular canals of the vestibular system to the brain. In the present study, we have characterized physiological eye movements evoked by focused, pulsed infrared radiation (IR) stimuli directed at an individual semicircular canal in a mammalian model. Pulsed IR (1863 nm) trains were directed at the posterior semicircular canal in a rat using 200-400 µm optical fibers. Evoked bilateral eye movements were measured using a custom-modified video-oculography system. The activation of vestibulo-ocular motor pathways by frequency modulated pulsed IR directed at single posterior semicircular canals evoked significant, characteristic bilateral eye movements. In this case, the resulting eye movements were disconjugate with ipsilateral eye moving upwards with a rotation towards the stimulated ear and the contralateral eye moving downwards. The eye movements were stable through several hours of repeated stimulation and could be maintained with 30 + minutes of continuous, frequency-modulated IR stimulation. Following the measurements, the distance of the fiber from target structures and orientation of the beam relative to vestibular structures were determined using micro-computed tomography. Results highlight the spatial selectivity of optical stimulation. Our results demonstrate a novel strategy for direct optical stimulation of the vestibular pathway in rodents and lays the groundwork for future applications of optical neural stimulation in inner ear research and therapeutic applications.
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Affiliation(s)
- Weitao Jiang
- Department of Biomedical Engineering, University of Miami, 1251 Memorial Drive, MEA 204, Coral Gables, FL, 33146, USA
| | - Suhrud M Rajguru
- Department of Biomedical Engineering, University of Miami, 1251 Memorial Drive, MEA 204, Coral Gables, FL, 33146, USA.
- Department of Otolaryngology, University of Miami, 1600 NW 10th Ave, RMSB 3160, Miami, FL, 33136, USA.
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21
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Distinct behavioral responses evoked by selective optogenetic stimulation of the major TRPV1+ and MrgD+ subsets of C-fibers. Pain 2018; 158:2329-2339. [PMID: 28708765 DOI: 10.1097/j.pain.0000000000001016] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Primary C-fiber nociceptors are broadly divided into peptidergic and nonpeptidergic afferents. TRPV1 is a thermosensitive cation channel mainly localized in peptidergic nociceptors, whereas MrgD is a sensory G protein-coupled receptor expressed in most nonpeptidergic nociceptive afferents. TRPV1 and MrgD fibers have been reported to be primarily involved in thermal and mechanical nociception, respectively. Yet, their functional assessment in somatosensory transmission relied on ablation strategies that do not account for compensatory mechanisms. To achieve selective activation of these 2 major subsets of C-fibers in vivo in adult mice, we used optogenetics to specifically deliver the excitatory opsin channelrhodopsin-2 (ChR2) to TRPV1 or MrgD primary sensory neurons, as confirmed by histology and electrophysiology. This approach allowed, for the first time, the characterization of behavioral responses triggered by direct noninvasive activation of peptidergic TRPV1 or nonpeptidergic MrgD fibers in freely moving mice. Transdermal blue light stimulation of the hind paws of transgenic mice expressing ChR2 in TRPV1 neurons generated nocifensive behaviors consisting mainly of paw withdrawal and paw licking, whereas paw lifting occurrence was limited. Conversely, optical activation of cutaneous MrgD afferents produced mostly withdrawal and lifting. Of interest, in a conditioned place avoidance assay, blue light induced aversion in TRPV1-ChR2 mice, but not in MrgD-ChR2 mice. In short, we present novel somatosensory transgenic models in which control of specific subsets of peripheral unmyelinated nociceptors with distinct functions can be achieved with high spatiotemporal precision. These new tools will be instrumental in further clarifying the contribution of genetically identified C-fiber subtypes to chronic pain.
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22
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Barnett SC, Perry BAL, Dalrymple-Alford JC, Parr-Brownlie LC. Optogenetic stimulation: Understanding memory and treating deficits. Hippocampus 2018; 28:457-470. [DOI: 10.1002/hipo.22960] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 04/24/2018] [Accepted: 05/02/2018] [Indexed: 01/01/2023]
Affiliation(s)
- S. C. Barnett
- Department of Psychology; University of Canterbury; Christchurch 8041 New Zealand
- Brain Research New Zealand; New Zealand
| | - B. A. L. Perry
- Department of Psychology; University of Canterbury; Christchurch 8041 New Zealand
- Brain Research New Zealand; New Zealand
| | - J. C. Dalrymple-Alford
- Department of Psychology; University of Canterbury; Christchurch 8041 New Zealand
- Brain Research New Zealand; New Zealand
- New Zealand Brain Research Institute; Christchurch New Zealand
| | - L. C. Parr-Brownlie
- Brain Research New Zealand; New Zealand
- Department of Anatomy, School of Biomedical Science; Brain Health Research Centre, University of Otago; Dunedin New Zealand
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23
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Optogenetic Tools for Subcellular Applications in Neuroscience. Neuron 2017; 96:572-603. [PMID: 29096074 DOI: 10.1016/j.neuron.2017.09.047] [Citation(s) in RCA: 216] [Impact Index Per Article: 30.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 03/30/2017] [Accepted: 09/26/2017] [Indexed: 12/21/2022]
Abstract
The ability to study cellular physiology using photosensitive, genetically encoded molecules has profoundly transformed neuroscience. The modern optogenetic toolbox includes fluorescent sensors to visualize signaling events in living cells and optogenetic actuators enabling manipulation of numerous cellular activities. Most optogenetic tools are not targeted to specific subcellular compartments but are localized with limited discrimination throughout the cell. Therefore, optogenetic activation often does not reflect context-dependent effects of highly localized intracellular signaling events. Subcellular targeting is required to achieve more specific optogenetic readouts and photomanipulation. Here we first provide a detailed overview of the available optogenetic tools with a focus on optogenetic actuators. Second, we review established strategies for targeting these tools to specific subcellular compartments. Finally, we discuss useful tools and targeting strategies that are currently missing from the optogenetics repertoire and provide suggestions for novel subcellular optogenetic applications.
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Khamo JS, Krishnamurthy VV, Sharum SR, Mondal P, Zhang K. Applications of Optobiology in Intact Cells and Multicellular Organisms. J Mol Biol 2017; 429:2999-3017. [PMID: 28882542 DOI: 10.1016/j.jmb.2017.08.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Revised: 08/26/2017] [Accepted: 08/28/2017] [Indexed: 12/25/2022]
Abstract
Temporal kinetics and spatial coordination of signal transduction in cells are vital for cell fate determination. Tools that allow for precise modulation of spatiotemporal regulation of intracellular signaling in intact cells and multicellular organisms remain limited. The emerging optobiological approaches use light to control protein-protein interaction in live cells and multicellular organisms. Optobiology empowers light-mediated control of diverse cellular and organismal functions such as neuronal activity, intracellular signaling, gene expression, cell proliferation, differentiation, migration, and apoptosis. In this review, we highlight recent developments in optobiology, focusing on new features of second-generation optobiological tools. We cover applications of optobiological approaches in the study of cellular and organismal functions, discuss current challenges, and present our outlook. Taking advantage of the high spatial and temporal resolution of light control, optobiology promises to provide new insights into the coordination of signaling circuits in intact cells and multicellular organisms.
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Affiliation(s)
- John S Khamo
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | | | - Savanna R Sharum
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Payel Mondal
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Kai Zhang
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
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Beaudry H, Daou I, Ribeiro-da-Silva A, Séguéla P. Will optogenetics be used to treat chronic pain patients? Pain Manag 2017; 7:269-278. [PMID: 28726577 DOI: 10.2217/pmt-2016-0055] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Chronic pain affects a third of the population and current treatments produce limited relief and severe side effects. An alternative strategy to decrease pain would be to directly modulate somatosensory pathways using optogenetics. Optogenetics involves the use of genetically encoded and optically active proteins, namely opsins, to control neuronal circuits. In preclinical animal models, optical silencing of peripheral nociceptors has been shown to alleviate both inflammatory and neuropathic pain. An opsin-based gene therapy to treat chronic pain patients is not ready yet, but encouraging advances have been made in optical and viral technology. In view of the increasing burden of chronic pain in our aging society, innovative analgesic approaches based on optogenetics are definitely worth exploring.
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Affiliation(s)
- Hélène Beaudry
- Department of Neurology & Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Canada.,The Alan Edwards Centre for Research on Pain, McGill University, Montreal, Canada.,Department of Pharmacology & Therapeutics, McGill University, Montreal, Canada
| | - Ihab Daou
- Department of Neurology & Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Canada.,The Alan Edwards Centre for Research on Pain, McGill University, Montreal, Canada
| | - Alfredo Ribeiro-da-Silva
- The Alan Edwards Centre for Research on Pain, McGill University, Montreal, Canada.,Department of Pharmacology & Therapeutics, McGill University, Montreal, Canada
| | - Philippe Séguéla
- Department of Neurology & Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Canada.,The Alan Edwards Centre for Research on Pain, McGill University, Montreal, Canada
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Czapiński J, Kiełbus M, Kałafut J, Kos M, Stepulak A, Rivero-Müller A. How to Train a Cell-Cutting-Edge Molecular Tools. Front Chem 2017; 5:12. [PMID: 28344971 PMCID: PMC5344921 DOI: 10.3389/fchem.2017.00012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 02/20/2017] [Indexed: 12/28/2022] Open
Abstract
In biological systems, the formation of molecular complexes is the currency for all cellular processes. Traditionally, functional experimentation was targeted to single molecular players in order to understand its effects in a cell or animal phenotype. In the last few years, we have been experiencing rapid progress in the development of ground-breaking molecular biology tools that affect the metabolic, structural, morphological, and (epi)genetic instructions of cells by chemical, optical (optogenetic) and mechanical inputs. Such precise dissection of cellular processes is not only essential for a better understanding of biological systems, but will also allow us to better diagnose and fix common dysfunctions. Here, we present several of these emerging and innovative techniques by providing the reader with elegant examples on how these tools have been implemented in cells, and, in some cases, organisms, to unravel molecular processes in minute detail. We also discuss their advantages and disadvantages with particular focus on their translation to multicellular organisms for in vivo spatiotemporal regulation. We envision that further developments of these tools will not only help solve the processes of life, but will give rise to novel clinical and industrial applications.
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Affiliation(s)
- Jakub Czapiński
- Department of Biochemistry and Molecular Biology, Medical University of LublinLublin, Poland
- Postgraduate School of Molecular Medicine, Medical University of WarsawWarsaw, Poland
| | - Michał Kiełbus
- Department of Biochemistry and Molecular Biology, Medical University of LublinLublin, Poland
| | - Joanna Kałafut
- Department of Biochemistry and Molecular Biology, Medical University of LublinLublin, Poland
| | - Michał Kos
- Department of Biochemistry and Molecular Biology, Medical University of LublinLublin, Poland
| | - Andrzej Stepulak
- Department of Biochemistry and Molecular Biology, Medical University of LublinLublin, Poland
| | - Adolfo Rivero-Müller
- Department of Biochemistry and Molecular Biology, Medical University of LublinLublin, Poland
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi UniversityTurku, Finland
- Department of Biosciences, Åbo Akademi UniversityTurku, Finland
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Galvan A, Caiola MJ, Albaugh DL. Advances in optogenetic and chemogenetic methods to study brain circuits in non-human primates. J Neural Transm (Vienna) 2017; 125:547-563. [PMID: 28238201 DOI: 10.1007/s00702-017-1697-8] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 02/14/2017] [Indexed: 12/22/2022]
Abstract
Over the last 10 years, the use of opto- and chemogenetics to modulate neuronal activity in research applications has increased exponentially. Both techniques involve the genetic delivery of artificial proteins (opsins or engineered receptors) that are expressed on a selective population of neurons. The firing of these neurons can then be manipulated using light sources (for opsins) or by systemic administration of exogenous compounds (for chemogenetic receptors). Opto- and chemogenetic tools have enabled many important advances in basal ganglia research in rodent models, yet these techniques have faced a slow progress in non-human primate (NHP) research. In this review, we present a summary of the current state of these techniques in NHP research and outline some of the main challenges associated with the use of these genetic-based approaches in monkeys. We also explore cutting-edge developments that will facilitate the use of opto- and chemogenetics in NHPs, and help advance our understanding of basal ganglia circuits in normal and pathological conditions.
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Affiliation(s)
- Adriana Galvan
- Department of Neurology, Yerkes National Primate Research Center, School of Medicine, Emory University, Atlanta, GA, 30329, USA. .,Udall Center of Excellence for Parkinson's Disease Research, Emory University, 954 Gatewood Road NE, Atlanta, GA, 30329, USA. .,Department of Neurology, School of Medicine, Emory University, Atlanta, GA, 30322, USA.
| | - Michael J Caiola
- Department of Neurology, Yerkes National Primate Research Center, School of Medicine, Emory University, Atlanta, GA, 30329, USA.,Udall Center of Excellence for Parkinson's Disease Research, Emory University, 954 Gatewood Road NE, Atlanta, GA, 30329, USA
| | - Daniel L Albaugh
- Department of Neurology, Yerkes National Primate Research Center, School of Medicine, Emory University, Atlanta, GA, 30329, USA.,Udall Center of Excellence for Parkinson's Disease Research, Emory University, 954 Gatewood Road NE, Atlanta, GA, 30329, USA
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Abstract
The control of spatiotemporal dynamics in biological systems is a fundamental problem in nonlinear sciences and has important applications in engineering and medicine. Optogenetic tools combined with advanced optical technologies provide unique opportunities to develop and validate novel approaches to control spatiotemporal complexity in neuronal and cardiac systems. Understanding of the mechanisms and instabilities underlying the onset, perpetuation, and control of cardiac arrhythmias will enable the development and translation of novel therapeutic approaches. Here we describe in detail the preparation and optical mapping of transgenic channelrhodopsin-2 (ChR2) mouse hearts, cardiac cell cultures, and the optical setup for photostimulation using digital light processing.
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30
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Papp EA, Leergaard TB, Csucs G, Bjaalie JG. Brain-Wide Mapping of Axonal Connections: Workflow for Automated Detection and Spatial Analysis of Labeling in Microscopic Sections. Front Neuroinform 2016; 10:11. [PMID: 27148038 PMCID: PMC4835481 DOI: 10.3389/fninf.2016.00011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 02/26/2016] [Indexed: 01/11/2023] Open
Abstract
Axonal tracing techniques are powerful tools for exploring the structural organization of neuronal connections. Tracers such as biotinylated dextran amine (BDA) and Phaseolus vulgaris leucoagglutinin (Pha-L) allow brain-wide mapping of connections through analysis of large series of histological section images. We present a workflow for efficient collection and analysis of tract-tracing datasets with a focus on newly developed modules for image processing and assignment of anatomical location to tracing data. New functionality includes automatic detection of neuronal labeling in large image series, alignment of images to a volumetric brain atlas, and analytical tools for measuring the position and extent of labeling. To evaluate the workflow, we used high-resolution microscopic images from axonal tracing experiments in which different parts of the rat primary somatosensory cortex had been injected with BDA or Pha-L. Parameters from a set of representative images were used to automate detection of labeling in image series covering the entire brain, resulting in binary maps of the distribution of labeling. For high to medium labeling densities, automatic detection was found to provide reliable results when compared to manual analysis, whereas weak labeling required manual curation for optimal detection. To identify brain regions corresponding to labeled areas, section images were aligned to the Waxholm Space (WHS) atlas of the Sprague Dawley rat brain (v2) by custom-angle slicing of the MRI template to match individual sections. Based on the alignment, WHS coordinates were obtained for labeled elements and transformed to stereotaxic coordinates. The new workflow modules increase the efficiency and reliability of labeling detection in large series of images from histological sections, and enable anchoring to anatomical atlases for further spatial analysis and comparison with other data.
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Affiliation(s)
- Eszter A Papp
- Institute of Basic Medical Sciences, University of Oslo Oslo, Norway
| | | | - Gergely Csucs
- Institute of Basic Medical Sciences, University of Oslo Oslo, Norway
| | - Jan G Bjaalie
- Institute of Basic Medical Sciences, University of Oslo Oslo, Norway
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31
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Abstract
Unraveling the complex network of neural circuits that form the nervous system demands tools that can manipulate specific circuits. The recent evolution of genetic tools to target neural circuits allows an unprecedented precision in elucidating their function. Here we describe two general approaches for achieving circuit specificity. The first uses the genetic identity of a cell, such as a transcription factor unique to a circuit, to drive expression of a molecule that can manipulate cell function. The second uses the spatial connectivity of a circuit to achieve specificity: one genetic element is introduced at the origin of a circuit and the other at its termination. When the two genetic elements combine within a neuron, they can alter its function. These two general approaches can be combined to allow manipulation of neurons with a specific genetic identity by introducing a regulatory gene into the origin or termination of the circuit. We consider the advantages and disadvantages of both these general approaches with regard to specificity and efficacy of the manipulations. We also review the genetic techniques that allow gain- and loss-of-function within specific neural circuits. These approaches introduce light-sensitive channels (optogenetic) or drug sensitive channels (chemogenetic) into neurons that form specific circuits. We compare these tools with others developed for circuit-specific manipulation and describe the advantages of each. Finally, we discuss how these tools might be applied for identification of the neural circuits that mediate behavior and for repair of neural connections.
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Affiliation(s)
- Hong Geun Park
- Burke Medical Research Institute, White Plains, NY, USA.
| | - Jason B Carmel
- Burke Medical Research Institute, White Plains, NY, USA
- Brain and Mind Research Institute and Departments of Neurology and Pediatrics, Weill Cornell Medical College, New York, NY, USA
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Mayrhofer M, Mione M. The Toolbox for Conditional Zebrafish Cancer Models. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 916:21-59. [PMID: 27165348 DOI: 10.1007/978-3-319-30654-4_2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Here we describe the conditional zebrafish cancer toolbox, which allows for fine control of the expression of oncogenes or downregulation of tumor suppressors at the spatial and temporal level. Methods such as the Gal4/UAS or the Cre/lox systems paved the way to the development of elegant tumor models, which are now being used to study cancer cell biology, clonal evolution, identification of cancer stem cells and anti-cancer drug screening. Combination of these tools, as well as novel developments such as the promising genome editing system through CRISPR/Cas9 and clever application of light reactive proteins will enable the development of even more sophisticated zebrafish cancer models. Here, we introduce this growing toolbox of conditional transgenic approaches, discuss its current application in zebrafish cancer models and provide an outlook on future perspectives.
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Affiliation(s)
- Marie Mayrhofer
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany
| | - Marina Mione
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany.
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33
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Abstract
Neurostimulation as a therapeutic tool has been developed and used for a range of different diseases such as Parkinson's disease, epilepsy, and migraine. However, it is not known why the efficacy of the stimulation varies dramatically across patients or why some patients suffer from severe side effects. This is largely due to the lack of mechanistic understanding of neurostimulation. Hence, theoretical computational approaches to address this issue are in demand. This chapter provides a review of mechanistic computational modeling of brain stimulation. In particular, we will focus on brain diseases, where mechanistic models (e.g., neural population models or detailed neuronal models) have been used to bridge the gap between cellular-level processes of affected neural circuits and the symptomatic expression of disease dynamics. We show how such models have been, and can be, used to investigate the effects of neurostimulation in the diseased brain. We argue that these models are crucial for the mechanistic understanding of the effect of stimulation, allowing for a rational design of stimulation protocols. Based on mechanistic models, we argue that the development of closed-loop stimulation is essential in order to avoid inference with healthy ongoing brain activity. Furthermore, patient-specific data, such as neuroanatomic information and connectivity profiles obtainable from neuroimaging, can be readily incorporated to address the clinical issue of variability in efficacy between subjects. We conclude that mechanistic computational models can and should play a key role in the rational design of effective, fully integrated, patient-specific therapeutic brain stimulation.
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Kimtan T, Thupmongkol J, Williams JC, Thongpang S. Printable and transparent micro-electrocorticography (μECoG) for optogenetic applications. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2015; 2014:482-5. [PMID: 25570001 DOI: 10.1109/embc.2014.6943633] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Micro-electrocorticography (μECoG) displays advantages over traditional invasive methods. The μECoG electrode can record neural activity with high spatial-temporal resolution and it can reduce implantation side effects (e.g. vascular and local-neuronal damage, tissue encapsulation, infection). In this study, we propose a printable transparent μECoG electrode for optogenetic applications by using ultrasonic microfluid printing technique. The device is based on poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT: PSS) as a conductive polymer, polydimethylsiloxane (PDMS) as an insulating polymer and poly(chloro-para-xylylene) (Parylene-C) as the device substrate. We focus on ultrasonic microfluid printing due to its low production cost, excellent material handling capability, and its customizable film thickness (down to 5-20 microns). The ultrasonic fluid-printed μECoG displays high spatial resolution and records simulated signal (0-200 Hz sine wave) effectively with low electrode impedance (50-200 kOhms@1kHz). The μECoG also shows good biocompatibility suitable for customizable chronic implants. This new neural interfacing device could be combined with optogenetics and Brain-Computer Interface (BCI) applications for a possible future use in neurological disease diagnosis and rehabilitations.
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Microbial Rhodopsin Optogenetic Tools: Application for Analyses of Synaptic Transmission and of Neuronal Network Activity in Behavior. Methods Mol Biol 2015; 1327:87-103. [PMID: 26423970 DOI: 10.1007/978-1-4939-2842-2_8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Optogenetics was introduced as a new technology in the neurosciences about a decade ago (Zemelman et al., Neuron 33:15-22, 2002; Boyden et al., Nat Neurosci 8:1263-1268, 2005; Nagel et al., Curr Biol 15:2279-2284, 2005; Zemelman et al., Proc Natl Acad Sci USA 100:1352-1357, 2003). It combines optics, genetics, and bioengineering to render neurons sensitive to light, in order to achieve a precise, exogenous, and noninvasive control of membrane potential, intracellular signaling, network activity, or behavior (Rein and Deussing, Mol Genet Genomics 287:95-109, 2012; Yizhar et al., Neuron 71:9-34, 2011). As C. elegans is transparent, genetically amenable, has a small nervous system mapped with synapse resolution, and exhibits a rich behavioral repertoire, it is especially open to optogenetic methods (White et al., Philos Trans R Soc Lond B Biol Sci 314:1-340, 1986; De Bono et al., Optogenetic actuation, inhibition, modulation and readout for neuronal networks generating behavior in the nematode Caenorhabditis elegans, In: Hegemann P, Sigrist SJ (eds) Optogenetics, De Gruyter, Berlin, 2013; Husson et al., Biol Cell 105:235-250, 2013; Xu and Kim, Nat Rev Genet 12:793-801, 2011). Optogenetics, by now an "exploding" field, comprises a repertoire of different tools ranging from transgenically expressed photo-sensor proteins (Boyden et al., Nat Neurosci 8:1263-1268, 2005; Nagel et al., Curr Biol 15:2279-2284, 2005) or cascades (Zemelman et al., Neuron 33:15-22, 2002) to chemical biology approaches, using photochromic ligands of endogenous channels (Szobota et al., Neuron 54:535-545, 2007). Here, we will focus only on optogenetics utilizing microbial rhodopsins, as these are most easily and most widely applied in C. elegans. For other optogenetic tools, for example the photoactivated adenylyl cyclases (PACs, that drive neuronal activity by increasing synaptic vesicle priming, thus exaggerating rather than overriding the intrinsic activity of a neuron, as occurs with rhodopsins), we refer to other literature (Weissenberger et al., J Neurochem 116:616-625, 2011; Steuer Costa et al., Photoactivated adenylyl cyclases as optogenetic modulators of neuronal activity, In: Cambridge S (ed) Photswitching proteins, Springer, New York, 2014). In this chapter, we will give an overview of rhodopsin-based optogenetic tools, their properties and function, as well as their combination with genetically encoded indicators of neuronal activity. As there is not "the" single optogenetic experiment we could describe here, we will focus more on general concepts and "dos and don'ts" when designing an optogenetic experiment. We will also give some guidelines on which hardware to use, and then describe a typical example of an optogenetic experiment to analyze the function of the neuromuscular junction, and another application, which is Ca(2+) imaging in body wall muscle, with upstream neuronal excitation using optogenetic stimulation. To obtain a more general overview of optogenetics and optogenetic tools, we refer the reader to an extensive collection of review articles, and in particular to volume 1148 of this book series, "Photoswitching Proteins."
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AzimiHashemi N, Erbguth K, Vogt A, Riemensperger T, Rauch E, Woodmansee D, Nagpal J, Brauner M, Sheves M, Fiala A, Kattner L, Trauner D, Hegemann P, Gottschalk A, Liewald JF. Synthetic retinal analogues modify the spectral and kinetic characteristics of microbial rhodopsin optogenetic tools. Nat Commun 2014; 5:5810. [PMID: 25503804 DOI: 10.1038/ncomms6810] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Accepted: 11/10/2014] [Indexed: 11/09/2022] Open
Abstract
Optogenetic tools have become indispensable in neuroscience to stimulate or inhibit excitable cells by light. Channelrhodopsin-2 (ChR2) variants have been established by mutating the opsin backbone or by mining related algal genomes. As an alternative strategy, we surveyed synthetic retinal analogues combined with microbial rhodopsins for functional and spectral properties, capitalizing on assays in C. elegans, HEK cells and larval Drosophila. Compared with all-trans retinal (ATR), Dimethylamino-retinal (DMAR) shifts the action spectra maxima of ChR2 variants H134R and H134R/T159C from 480 to 520 nm. Moreover, DMAR decelerates the photocycle of ChR2(H134R) and (H134R/T159C), thereby reducing the light intensity required for persistent channel activation. In hyperpolarizing archaerhodopsin-3 and Mac, naphthyl-retinal and thiophene-retinal support activity alike ATR, yet at altered peak wavelengths. Our experiments enable applications of retinal analogues in colour tuning and altering photocycle characteristics of optogenetic tools, thereby increasing the operational light sensitivity of existing cell lines or transgenic animals.
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Affiliation(s)
- N AzimiHashemi
- 1] Buchmann Institute for Molecular Life Sciences (BMLS), Goethe-University, Max-von-Laue-Straße 15, 60438 Frankfurt, Germany [2] Institute of Biochemistry, Goethe-University, Max-von-Laue-Straße 9, 60438 Frankfurt, Germany
| | - K Erbguth
- 1] Buchmann Institute for Molecular Life Sciences (BMLS), Goethe-University, Max-von-Laue-Straße 15, 60438 Frankfurt, Germany [2] Institute of Biochemistry, Goethe-University, Max-von-Laue-Straße 9, 60438 Frankfurt, Germany
| | - A Vogt
- Institute for Biology-Experimental Biophysics, Humboldt-Universität zu Berlin, Invalidenstraße 42, 10115 Berlin, Germany
| | - T Riemensperger
- Department of Molecular Neurobiology of Behavior, Georg-August-Universität Göttingen, Julia-Lermontowa-Weg 3, 37077 Göttingen, Germany
| | - E Rauch
- Endotherm, Science-Park II, 66123 Saarbrücken, Germany
| | - D Woodmansee
- Department of Chemistry, Ludwig-Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany
| | - J Nagpal
- 1] Buchmann Institute for Molecular Life Sciences (BMLS), Goethe-University, Max-von-Laue-Straße 15, 60438 Frankfurt, Germany [2] Institute of Biochemistry, Goethe-University, Max-von-Laue-Straße 9, 60438 Frankfurt, Germany
| | - M Brauner
- Institute of Biochemistry, Goethe-University, Max-von-Laue-Straße 9, 60438 Frankfurt, Germany
| | - M Sheves
- Department of Organic Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - A Fiala
- Department of Molecular Neurobiology of Behavior, Georg-August-Universität Göttingen, Julia-Lermontowa-Weg 3, 37077 Göttingen, Germany
| | - L Kattner
- Endotherm, Science-Park II, 66123 Saarbrücken, Germany
| | - D Trauner
- Department of Chemistry, Ludwig-Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany
| | - P Hegemann
- Institute for Biology-Experimental Biophysics, Humboldt-Universität zu Berlin, Invalidenstraße 42, 10115 Berlin, Germany
| | - A Gottschalk
- 1] Buchmann Institute for Molecular Life Sciences (BMLS), Goethe-University, Max-von-Laue-Straße 15, 60438 Frankfurt, Germany [2] Institute of Biochemistry, Goethe-University, Max-von-Laue-Straße 9, 60438 Frankfurt, Germany [3] Cluster of Excellence Frankfurt Macromolecular Complexes (CEF-MC), Goethe University, Max-von-Laue Straße 15 60438, Frankfurt, Germany
| | - J F Liewald
- 1] Buchmann Institute for Molecular Life Sciences (BMLS), Goethe-University, Max-von-Laue-Straße 15, 60438 Frankfurt, Germany [2] Institute of Biochemistry, Goethe-University, Max-von-Laue-Straße 9, 60438 Frankfurt, Germany
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Shui B, Lee JC, Reining S, Lee FK, Kotlikoff MI. Optogenetic sensors and effectors: CHROMus-the Cornell Heart Lung Blood Institute Resource for Optogenetic Mouse Signaling. Front Physiol 2014; 5:428. [PMID: 25414670 PMCID: PMC4222331 DOI: 10.3389/fphys.2014.00428] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 10/15/2014] [Indexed: 01/21/2023] Open
Abstract
Significant progress has been made in the last decade in the development of optogenetic effectors and sensors that can be deployed to understand complex biological signaling in mammals at a molecular level, without disrupting the distributed, lineage specific signaling circuits that comprise nuanced physiological responses. A major barrier to the widespread exploitation of these imaging tools, however, is the lack of readily available genetic reagents that can be easily combined to probe complex biological processes. Ideally, one could envision purpose–produced mouse lines expressing optically compatible sensors and effectors, sensor pairs in distinct lineages, or sensor pairs in discrete subcellular compartments, such that they could be crossed to enable in vivo imaging studies of unprecedented scientific power. Such lines could also be combined with mice to determine the alteration in signaling accompanying targeted gene deletion or addition. In order to address this lack, the National Heart Lung and Blood Institute has recently funded an optogenetic resource designed to create optically compatible, combinatorial mouse lines that will advance NHLBI research. Here we review recent advances in optogenetic sensor and effectors and describe the rationale and goals for the establishment of the Cornell/National Heart Lung Blood Resource for Optogenetic Mouse Signaling (CHROMus).
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Affiliation(s)
- Bo Shui
- Department of Biomedical Sciences, College of Veteirnary Medicine, Cornell University Ithaca, NY, USA
| | - Jane C Lee
- Department of Biomedical Sciences, College of Veteirnary Medicine, Cornell University Ithaca, NY, USA
| | - Shaun Reining
- Department of Biomedical Sciences, College of Veteirnary Medicine, Cornell University Ithaca, NY, USA
| | - Frank K Lee
- Department of Biomedical Sciences, College of Veteirnary Medicine, Cornell University Ithaca, NY, USA
| | - Michael I Kotlikoff
- Department of Biomedical Sciences, College of Veteirnary Medicine, Cornell University Ithaca, NY, USA
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Deng W, Goldys EM, Farnham MMJ, Pilowsky PM. Optogenetics, the intersection between physics and neuroscience: light stimulation of neurons in physiological conditions. Am J Physiol Regul Integr Comp Physiol 2014; 307:R1292-302. [PMID: 25274906 DOI: 10.1152/ajpregu.00072.2014] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Neuronal stimulation by light is a novel approach in the emerging field of optogenetics, where genetic engineering is used to introduce light-activated channels. However, light is also capable of stimulating neurons even in the absence of genetic modifications through a range of physical and biological mechanisms. As a result, rigorous design of optogenetic experiments needs to take note of alternative and parallel effects of light illumination of neuronal tissues. Thus all matters relating to light penetration are critical to the development of studies using light-activated proteins. This paper discusses ways to quantify light, light penetration in tissue, as well as light stimulation of neurons in physiological conditions. We also describe the direct effect of light on neurons investigated at different sites.
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Affiliation(s)
- Wei Deng
- Physics and Astronomy Department, Macquarie University, Sydney, Australia; and
| | - Ewa M Goldys
- Physics and Astronomy Department, Macquarie University, Sydney, Australia; and
| | | | - Paul M Pilowsky
- Heart Research Institute and Sydney University, Sydney, Australia
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Belzung C, Turiault M, Griebel G. Optogenetics to study the circuits of fear- and depression-like behaviors: A critical analysis. Pharmacol Biochem Behav 2014; 122:144-57. [DOI: 10.1016/j.pbb.2014.04.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 03/31/2014] [Accepted: 04/03/2014] [Indexed: 02/05/2023]
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40
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Effect of Optogenetic Stimulus on the Proliferation and Cell Cycle Progression of Neural Stem Cells. J Membr Biol 2014; 247:493-500. [DOI: 10.1007/s00232-014-9659-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2013] [Accepted: 03/17/2014] [Indexed: 12/29/2022]
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Wang YT, Gu S, Ma P, Watanabe M, Rollins AM, Jenkins MW. Optical stimulation enables paced electrophysiological studies in embryonic hearts. BIOMEDICAL OPTICS EXPRESS 2014; 5:1000-13. [PMID: 24761284 PMCID: PMC3985989 DOI: 10.1364/boe.5.001000] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 02/13/2014] [Accepted: 02/21/2014] [Indexed: 05/11/2023]
Abstract
Cardiac electrophysiology plays a critical role in the development and function of the heart. Studies of early embryonic electrical activity have lacked a viable point stimulation technique to pace in vitro samples. Here, optical pacing by high-precision infrared stimulation is used to pace excised embryonic hearts, allowing electrophysiological parameters to be quantified during pacing at varying rates with optical mapping. Combined optical pacing and optical mapping enables electrophysiological studies in embryos under more physiological conditions and at varying heart rates, allowing detection of abnormal conduction and comparisons between normal and pathological electrical activity during development in various models.
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Affiliation(s)
- Yves T. Wang
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, 44120, USA
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH, 44120, USA
| | - Shi Gu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, 44120, USA
| | - Pei Ma
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, 44120, USA
| | - Michiko Watanabe
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH, 44120, USA
| | - Andrew M. Rollins
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, 44120, USA
| | - Michael W. Jenkins
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, 44120, USA
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH, 44120, USA
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42
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Herman AM, Huang L, Murphey DK, Garcia I, Arenkiel BR. Cell type-specific and time-dependent light exposure contribute to silencing in neurons expressing Channelrhodopsin-2. eLife 2014; 3:e01481. [PMID: 24473077 PMCID: PMC3904216 DOI: 10.7554/elife.01481] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Channelrhodopsin-2 (ChR2) has quickly gained popularity as a powerful tool for eliciting genetically targeted neuronal activation. However, little has been reported on the response kinetics of optogenetic stimulation across different neuronal subtypes. With excess stimulation, neurons can be driven into depolarization block, a state where they cease to fire action potentials. Herein, we demonstrate that light-induced depolarization block in neurons expressing ChR2 poses experimental challenges for stable activation of specific cell types and may confound interpretation of experiments when ‘activated’ neurons are in fact being functionally silenced. We show both ex vivo and in vivo that certain neuronal subtypes targeted for ChR2 expression become increasingly susceptible to depolarization block as the duration of light pulses are increased. We find that interneuron populations have a greater susceptibility to this effect than principal excitatory neurons, which are more resistant to light-induced depolarization block. Our results highlight the need to empirically determine the photo-response properties of targeted neurons when using ChR2, particularly in studies designed to elicit complex circuit responses in vivo where neuronal activity will not be recorded simultaneous to light stimulation. DOI:http://dx.doi.org/10.7554/eLife.01481.001 The brain is a highly complex structure composed of trillions of interconnecting nerve cells. The pattern of connections between these cells gives rise to the various brain circuits that govern how the brain functions. Understanding how the brain is wired together is important for determining how ‘faulty circuits’ contribute to various neurological disorders. New optogenetic technique tools allow neuroscientists to turn on specific neurons simply by shining light on them. These techniques involve genetically manipulating the organisms so that their neurons express proteins that are activated when they are exposed to light of a particular wavelength. However, it is important to understand the limitations of this approach—including the possibility that the light might actually turn off some neurons—when using it to study animal behavior. Now, Herman, Huang et al. show that shining light pulses for long durations onto neurons expressing a light-activated protein called channelrhodopsin-2 causes the neurons to become silenced rather than activated. Moreover, certain types of neurons, called interneurons, are more susceptible to this effect—termed ‘depolarization block’—than the other types of neurons. Researchers need to be mindful of this effect when channelrhodopsin-2 is used in optogenetic experiments to study the behavior of living animals. However, this silencing property could be useful in experiments that investigate situations in which depolarization block is thought to contribute to brain function and health: such as in the treatments of schizophrenia and Parkinson’s disease. DOI:http://dx.doi.org/10.7554/eLife.01481.002
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Affiliation(s)
- Alexander M Herman
- Program in Developmental Biology, Baylor College of Medicine, Houston, United States
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43
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Abstract
Optogenetics, the use of light to stimulate or inhibit neural circuits via viral transduction of protein channels, has emerged as a possible method of treating epilepsy. By introducing viral vectors carrying algal-derived cation or anion channels, known as opsins, neurons that initiate or propagate seizures may be silenced. To date, studies using this technique have been performed in animal models, and current efforts are moving toward more sophisticated nonhuman primate models. In this paper, the authors present a brief overview of the development of optogenetics and review recent studies investigating optogenetic modification of circuits involved in seizures. Further developments in the field are explored, with an emphasis on how optogenetics may influence future neurosurgical interventions.
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Affiliation(s)
- J Nicole Bentley
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI 48109, USA
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Gratwicke J, Kahan J, Zrinzo L, Hariz M, Limousin P, Foltynie T, Jahanshahi M. The nucleus basalis of Meynert: A new target for deep brain stimulation in dementia? Neurosci Biobehav Rev 2013; 37:2676-88. [DOI: 10.1016/j.neubiorev.2013.09.003] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 08/30/2013] [Accepted: 09/02/2013] [Indexed: 10/26/2022]
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Smedemark-Margulies N, Trapani JG. Tools, methods, and applications for optophysiology in neuroscience. Front Mol Neurosci 2013; 6:18. [PMID: 23882179 PMCID: PMC3713398 DOI: 10.3389/fnmol.2013.00018] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Accepted: 06/27/2013] [Indexed: 11/13/2022] Open
Abstract
The advent of optogenetics and genetically encoded photosensors has provided neuroscience researchers with a wealth of new tools and methods for examining and manipulating neuronal function in vivo. There exists now a wide range of experimentally validated protein tools capable of modifying cellular function, including light-gated ion channels, recombinant light-gated G protein-coupled receptors, and even neurotransmitter receptors modified with tethered photo-switchable ligands. A large number of genetically encoded protein sensors have also been developed to optically track cellular activity in real time, including membrane-voltage-sensitive fluorophores and fluorescent calcium and pH indicators. The development of techniques for controlled expression of these proteins has also increased their utility by allowing the study of specific populations of cells. Additionally, recent advances in optics technology have enabled both activation and observation of target proteins with high spatiotemporal fidelity. In combination, these methods have great potential in the study of neural circuits and networks, behavior, animal models of disease, as well as in high-throughput ex vivo studies. This review collects some of these new tools and methods and surveys several current and future applications of the evolving field of optophysiology.
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Abstract
Nestin-Cre mice have a significant metabolic phenotype that is hard to discern from current literature. Indeed, the Cre-lox system has numerous problems that can affect physiological parameters, and these are missed when the correct control strains are not used. Despite the increasing use of the Cre-lox system, these issues were not visible to the scientific community previously and may have affected published work. This makes it important to highlight the issues and raise awareness of the pitfalls of the Cre-lox system. Therefore, this perspective will discuss the impact of CNS and peripheral "off-target" Cre recombination on metabolic systems and describe the development of new approaches to obviate the difficulties.
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Affiliation(s)
- Erika Harno
- Neuroscience Research Group, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
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Müller K, Weber W. Optogenetic tools for mammalian systems. MOLECULAR BIOSYSTEMS 2013; 9:596-608. [DOI: 10.1039/c3mb25590e] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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48
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Höckendorf B, Thumberger T, Wittbrodt J. Quantitative Analysis of Embryogenesis: A Perspective for Light Sheet Microscopy. Dev Cell 2012; 23:1111-20. [DOI: 10.1016/j.devcel.2012.10.008] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 10/04/2012] [Accepted: 10/04/2012] [Indexed: 01/06/2023]
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Erbguth K, Prigge M, Schneider F, Hegemann P, Gottschalk A. Bimodal activation of different neuron classes with the spectrally red-shifted channelrhodopsin chimera C1V1 in Caenorhabditis elegans. PLoS One 2012; 7:e46827. [PMID: 23056472 PMCID: PMC3463556 DOI: 10.1371/journal.pone.0046827] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 09/06/2012] [Indexed: 11/24/2022] Open
Abstract
The C. elegans nervous system is particularly well suited for optogenetic analyses of circuit function: Essentially all connections have been mapped, and light can be directed at the neuron of interest in the freely moving, transparent animals, while behavior is observed. Thus, different nodes of a neuronal network can be probed for their role in controlling a particular behavior, using different optogenetic tools for photo-activation or –inhibition, which respond to different colors of light. As neurons may act in concert or in opposing ways to affect a behavior, one would further like to excite these neurons concomitantly, yet independent of each other. In addition to the blue-light activated Channelrhodopsin-2 (ChR2), spectrally red-shifted ChR variants have been explored recently. Here, we establish the green-light activated ChR chimera C1V1 (from Chlamydomonas and Volvox ChR1′s) for use in C. elegans. We surveyed a number of red-shifted ChRs, and found that C1V1-ET/ET (E122T; E162T) works most reliable in C. elegans, with 540–580 nm excitation, which leaves ChR2 silent. However, as C1V1-ET/ET is very light sensitive, it still becomes activated when ChR2 is stimulated, even at 400 nm. Thus, we generated a highly efficient blue ChR2, the H134R; T159C double mutant (ChR2-HR/TC). Both proteins can be used in the same animal, in different neurons, to independently control each cell type with light, enabling a further level of complexity in circuit analyses.
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Affiliation(s)
- Karen Erbguth
- Buchmann Institute for Molecular Life Sciences, Goethe-University, Frankfurt, Germany
- Institute of Biochemistry, Goethe-University, Frankfurt, Germany
| | - Matthias Prigge
- Institute of Biology (Experimental Biophysics), Humboldt-University, Berlin, Germany
| | - Franziska Schneider
- Institute of Biology (Experimental Biophysics), Humboldt-University, Berlin, Germany
| | - Peter Hegemann
- Institute of Biology (Experimental Biophysics), Humboldt-University, Berlin, Germany
| | - Alexander Gottschalk
- Buchmann Institute for Molecular Life Sciences, Goethe-University, Frankfurt, Germany
- Institute of Biochemistry, Goethe-University, Frankfurt, Germany
- * E-mail:
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