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Mellor NG, Chung SA, Graham ES, Day BW, Unsworth CP. Eliciting calcium transients with UV nanosecond laser stimulation in adult patient-derived glioblastoma brain cancer cells in vitro. J Neural Eng 2023; 20:066026. [PMID: 37988746 DOI: 10.1088/1741-2552/ad0e7d] [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: 10/03/2022] [Accepted: 11/21/2023] [Indexed: 11/23/2023]
Abstract
Objective.Glioblastoma (GBM) is the most common and lethal type of high-grade adult brain cancer. The World Health Organization have classed GBM as an incurable disease because standard treatments have yielded little improvement with life-expectancy being 6-15 months after diagnosis. Different approaches are now crucial to discover new knowledge about GBM communication/function in order to establish alternative therapies for such an aggressive adult brain cancer. Calcium (Ca2+) is a fundamental cell molecular messenger employed in GBM being involved in a wide dynamic range of cellular processes. Understanding how the movement of Ca2+behaves and modulates activity in GBM at the single-cell level is relatively unexplored but holds the potential to yield opportunities for new therapeutic strategies and approaches for cancer treatment.Approach.In this article we establish a spatially and temporally precise method for stimulating Ca2+transients in three patient-derived GBM cell-lines (FPW1, RN1, and RKI1) such that Ca2+communication can be studied from single-cell to larger network scales. We demonstrate that this is possible by administering a single optimized ultra-violet (UV) nanosecond laser pulse to trigger GBM Ca2+transients.Main results.We determine that 1.58µJµm-2is the optimal UV nanosecond laser pulse energy density necessary to elicit a single Ca2+transient in the GBM cell-lines whilst maintaining viability, functionality, the ability to be stimulated many times in an experiment, and to trigger further Ca2+communication in a larger network of GBM cells.Significance.Using adult patient-derived mesenchymal GBM brain cancer cell-lines, the most aggressive form of GBM cancer, this work is the first of its kind as it provides a new effective modality of which to stimulate GBM cells at the single-cell level in an accurate, repeatable, and reliable manner; and is a first step toward Ca2+communication in GBM brain cancer cells and their networks being more effectively studied.
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Affiliation(s)
- Nicholas G Mellor
- Department of Engineering Science, The University of Auckland, Auckland, New Zealand
| | - Sylvia A Chung
- Adult Cancer Program, Lowy Cancer Research Centre, The University of New South Wales, Sydney, Australia
| | - E Scott Graham
- Department of Molecular Medicine and Pathology & The Centre for Brain Research, The University of Auckland, Auckland, New Zealand
| | - Bryan W Day
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Charles P Unsworth
- Department of Engineering Science, The University of Auckland, Auckland, New Zealand
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Li S, Graham ES, Unsworth CP. Extracellular ATP release predominantly mediates Ca2+ communication locally in highly organised, stellate-Like patterned networks of adult human astrocytes. PLoS One 2023; 18:e0289350. [PMID: 37788259 PMCID: PMC10547170 DOI: 10.1371/journal.pone.0289350] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 07/17/2023] [Indexed: 10/05/2023] Open
Abstract
The 'Astrocyte Network' and the understanding of its communication has been posed as a new grand challenge to be investigated by contemporary science. However, communication studies in astrocyte networks have investigated traditional petri-dish in vitro culture models where cells are closely packed and can deviate from the stellate form observed in the brain. Using novel cell patterning approaches, highly organised, regular grid networks of astrocytes on chip, to single-cell fidelity are constructed, permitting a stellate-like in vitro network model to be realised. By stimulating the central cell with a single UV nanosecond laser pulse, the initiation/propagation pathways of stellate-like networks are re-explored. The authors investigate the mechanisms of intercellular Ca2+ communication and discover that stellate-like networks of adult human astrocytes in vitro actually exploit extracellular ATP release as their dominant propagation pathway to cells in the network locally; being observed even down to the nearest neighbour and next nearest neighbouring cells-contrary to the reported gap junction. This discovery has significant ramifications to many neurological conditions such as epilepsy, stroke and aggressive astrocytomas where gap junctions can be targeted. In cases where such gap junction targeting has failed, this new finding suggests that these conditions should be re-visited and the ATP transmission pathway targeted instead.
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Affiliation(s)
- Si Li
- Department of Engineering Science, The University of Auckland, Auckland, New Zealand
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Auckland, New Zealand
| | - E. Scott Graham
- Department of Molecular Medicine and Pathology & Centre for Brain Research, The University of Auckland, Auckland, New Zealand
| | - Charles P. Unsworth
- Department of Engineering Science, The University of Auckland, Auckland, New Zealand
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Auckland, New Zealand
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3
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Mellor NG, Cheung SA, Graham ES, Day BW, Unsworth CP. UV Laser Stimulation of Ca 2+ Transients in Aggressive Glioblastoma Brain Cancer Cells . ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023; 2023:1-4. [PMID: 38083047 DOI: 10.1109/embc40787.2023.10341039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
Glioblastoma (GBM) is a lethal astrocytoma being the most common highest-grade adult brain cancer. GBM tumours are highly invasive and display rapid growth to surrounding areas of the brain. Despite treatment, diagnosed patients continue to have poor prognosis with average survival time of 8 months. Calcium (Ca2+) is a main communication channel used in GBM and its understanding holds the potential to unlock new approaches to treatment. The aim of this work is to provide a first step to accurately evoking Ca2+ transients in GBM cells using single UV nanosecond laser pulses in vitro such that this communication pathway can be more reliably studied from the single-cell to the network level.
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Liu S, Chen D, Xie Z, Zhao S, Tang W, He H, Ho YP, Ho HP, Kong SK. A high spatial resolution osteogenic differentiation in human mesenchymal stem cells induced by femtosecond laser. JOURNAL OF BIOPHOTONICS 2022; 15:e202200144. [PMID: 35852043 DOI: 10.1002/jbio.202200144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 06/28/2022] [Accepted: 07/01/2022] [Indexed: 06/15/2023]
Abstract
A variety of physical and chemical methods have been developed in research laboratories for the induction of stem cell differentiation. However, the use of exogenous chemicals and materials may limit their widespread utility in clinics. To develop a clean and precise induction approach with minimal invasion, we reported here that 1-second stimulation by a tightly focused femtosecond laser (fsL) (140 mW/μm2 , 200 fs) can modulate the signaling systems in human mesenchymal cells, such as intracellular calcium and reactive oxygen species. Upon stimulation on an automatic platform, hMSCs were found to express osteoblastic markers and form calcium-rich deposits. Moreover, tissue mineralization was observed when the fsL-illuminated hMSCs were ectopically transplanted into nude mice. Collectively, we described a novel and non-contact optical stimulation method for cell differentiation with high spatiotemporal resolution.
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Affiliation(s)
- Shiyue Liu
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Dihan Chen
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Zhenming Xie
- Department of Biomedical Engineering, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Shirui Zhao
- Department of Biomedical Engineering, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Wanyi Tang
- Med-X Research Institute, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Hao He
- Med-X Research Institute, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Yi-Ping Ho
- Department of Biomedical Engineering, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Ho-Pui Ho
- Department of Biomedical Engineering, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Siu-Kai Kong
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, SAR, China
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5
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Tian X, He H. Activation of Mitochondrial Ca 2+ Oscillation and Mitophagy Induction by Femtosecond Laser Photostimulation. Bio Protoc 2022; 12:e4369. [PMID: 35991968 PMCID: PMC9382407 DOI: 10.21769/bioprotoc.4369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 11/22/2021] [Accepted: 02/14/2022] [Indexed: 12/29/2022] Open
Abstract
Ultra-precise stimulation solely to individual mitochondria, without any influence to the whole cell, is quite difficult by traditional biochemical reagents. In mitophagy research, the mitochondria and even the whole cell usually suffer irreversible and great damage caused by treatment with potent chemicals. In this protocol, we present the technical procedures of our developed noninvasive ultra- precise laser stimulation (UPLaS) technology, which introduces precise stimulation to individual mitochondria, to excite mitochondrial Ca 2+ (mitoCa 2+ ) oscillations, with little perturbation to mitochondrial membrane potential (MMP), or mitochondrial reactive oxygen species (mitoROS). The mitoCa 2+ oscillation by UPLaS was able to initiate the PINK1/Parkin pathway for mitophagy. This protocol has good potential to benefit researches on mitophagy and mitochondrial diseases. Graphic abstract: Figure 1.Flowchart of the UPLaS technology.The femtosecond laser (1030 nm, 1 MHz, 220 fs) can stimulate individual mitochondria (1 μm 2 ) for a short period (0.1 s), whereas confocal microscopy (CM) provides continuous cell imaging to monitor molecular dynamics in real time, before and after UPLaS.
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Affiliation(s)
- Xiaoying Tian
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Hao He
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China,*For correspondence:
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Current Review of Optical Neural Interfaces for Clinical Applications. MICROMACHINES 2021; 12:mi12080925. [PMID: 34442547 PMCID: PMC8400671 DOI: 10.3390/mi12080925] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/20/2021] [Accepted: 07/29/2021] [Indexed: 11/16/2022]
Abstract
Neural interfaces, which enable the recording and stimulation of living neurons, have emerged as valuable tools in understanding the brain in health and disease, as well as serving as neural prostheses. While neural interfaces are typically based on electrical transduction, alternative energy modalities have been explored to create safe and effective approaches. Among these approaches, optical methods of linking neurons to the outside world have gained attention because light offers high spatial selectivity and decreased invasiveness. Here, we review the current state-of-art of optical neural interfaces and their clinical applications. Optical neural interfaces can be categorized into optical control and optical readout, each of which can be divided into intrinsic and extrinsic approaches. We discuss the advantages and disadvantages of each of these methods and offer a comparison of relative performance. Future directions, including their clinical opportunities, are discussed with regard to the optical properties of biological tissue.
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7
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Li S, Graham ES, Unsworth CP. Nanosecond Laser Stimulation in an Organized Grid Network of Human Astrocytes. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2020:2245-2248. [PMID: 33018454 DOI: 10.1109/embc44109.2020.9175812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Recently, the study of communication in an 'Astrocyte Network' has been suggested to be of equal importance to that of the traditional 'Neural Network'. In this paper, for the first time, we use nanosecond laser stimulation to stimulate the central cell in an organized grid network of connected human astrocytes in order to observe calcium wave propagation at the single-cell level. We show that the calcium waves indeed propagate from the central astrocyte to the outer periphery of the organized astrocyte network. We observe also, like astrocytes in standard in vitro petri dishes, that the calcium wave propagates through specific connections to the outer periphery of cells rather than in a uniform radial manner predicted by mathematical theory. The results show that such a platform provides an excellent environment to perform repeatable, controlled studies of calcium wave signal propagation through an organized grid network of human astrocytes at single-cell resolution.
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8
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Pham C, Moro DH, Mouffle C, Didienne S, Hepp R, Pfrieger FW, Mangin JM, Legendre P, Martin C, Luquet S, Cauli B, Li D. Mapping astrocyte activity domains by light sheet imaging and spatio-temporal correlation screening. Neuroimage 2020; 220:117069. [PMID: 32585347 DOI: 10.1016/j.neuroimage.2020.117069] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 06/12/2020] [Accepted: 06/15/2020] [Indexed: 02/08/2023] Open
Abstract
Astrocytes are a major type of glial cell in the mammalian brain, essentially regulating neuronal development and function. Quantitative imaging represents an important approach to study astrocytic signaling in neural circuits. Focusing on astrocytic Ca2+ activity, a key pathway implicated in astrocye-neuron interaction, we here report a strategy combining fast light sheet fluorescence microscopy (LSFM) and correlative screening-based time series analysis, to map activity domains in astrocytes in living mammalian nerve tissue. Light sheet of micron-scale thickness enables wide-field optical sectioning to image astrocytes in acute mouse brain slices. Using both chemical and genetically encoded Ca2+ indicators, we demonstrate the complementary advantages of LSFM in mapping Ca2+ domains in astrocyte populations as compared to epifluorescence and two-photon microscopy. Our approach then revealed distinct kinetics of Ca2+ signals between cortical and hypothalamic astrocytes in resting conditions and following the activation of adrenergic G protein coupled receptor (GPCR). This observation highlights the activity heterogeneity across regionally distinct astrocyte populations, and indicates the potential of our method for investigating dynamic signals in astrocytes.
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Affiliation(s)
- Cuong Pham
- Sorbonne Université, Institute of Biology Paris Seine, Neuroscience Paris Seine, CNRS UMR8246, INSERM U1130, UPMC UMCR18, Paris, 75005, France
| | - Daniela Herrera Moro
- Unité de Biologie Fonctionnelle et Adaptative, Centre National la Recherche Scientifique, Unité Mixte de Recherche 8251, Université Paris Diderot, Sorbonne Paris Cité, 75205, Paris, France
| | - Christine Mouffle
- Sorbonne Université, Institute of Biology Paris Seine, Neuroscience Paris Seine, CNRS UMR8246, INSERM U1130, UPMC UMCR18, Paris, 75005, France
| | - Steve Didienne
- Sorbonne Université, Institute of Biology Paris Seine, Neuroscience Paris Seine, CNRS UMR8246, INSERM U1130, UPMC UMCR18, Paris, 75005, France
| | - Régine Hepp
- Sorbonne Université, Institute of Biology Paris Seine, Neuroscience Paris Seine, CNRS UMR8246, INSERM U1130, UPMC UMCR18, Paris, 75005, France
| | - Frank W Pfrieger
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, F-67000, Strasbourg, France
| | - Jean-Marie Mangin
- Sorbonne Université, Institute of Biology Paris Seine, Neuroscience Paris Seine, CNRS UMR8246, INSERM U1130, UPMC UMCR18, Paris, 75005, France
| | - Pascal Legendre
- Sorbonne Université, Institute of Biology Paris Seine, Neuroscience Paris Seine, CNRS UMR8246, INSERM U1130, UPMC UMCR18, Paris, 75005, France
| | - Claire Martin
- Unité de Biologie Fonctionnelle et Adaptative, Centre National la Recherche Scientifique, Unité Mixte de Recherche 8251, Université Paris Diderot, Sorbonne Paris Cité, 75205, Paris, France
| | - Serge Luquet
- Unité de Biologie Fonctionnelle et Adaptative, Centre National la Recherche Scientifique, Unité Mixte de Recherche 8251, Université Paris Diderot, Sorbonne Paris Cité, 75205, Paris, France
| | - Bruno Cauli
- Sorbonne Université, Institute of Biology Paris Seine, Neuroscience Paris Seine, CNRS UMR8246, INSERM U1130, UPMC UMCR18, Paris, 75005, France
| | - Dongdong Li
- Sorbonne Université, Institute of Biology Paris Seine, Neuroscience Paris Seine, CNRS UMR8246, INSERM U1130, UPMC UMCR18, Paris, 75005, France.
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9
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Borrachero-Conejo AI, Adams WR, Saracino E, Mola MG, Wang M, Posati T, Formaggio F, De Bellis M, Frigeri A, Caprini M, Hutchinson MR, Muccini M, Zamboni R, Nicchia GP, Mahadevan-Jansen A, Benfenati V. Stimulation of water and calcium dynamics in astrocytes with pulsed infrared light. FASEB J 2020; 34:6539-6553. [PMID: 32202681 DOI: 10.1096/fj.201903049r] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 02/25/2020] [Accepted: 03/06/2020] [Indexed: 06/14/2024]
Abstract
Astrocytes are non-neuronal cells that govern the homeostatic regulation of the brain through ions and water transport, and Ca2+ -mediated signaling. As they are tightly integrated into neural networks, label-free tools that can modulate cell function are needed to evaluate the role of astrocytes in brain physiology and dysfunction. Using live-cell fluorescence imaging, pharmacology, electrophysiology, and genetic manipulation, we show that pulsed infrared light can modulate astrocyte function through changes in intracellular Ca2+ and water dynamics, providing unique mechanistic insight into the effect of pulsed infrared laser light on astroglial cells. Water transport is activated and, IP3 R, TRPA1, TRPV4, and Aquaporin-4 are all involved in shaping the dynamics of infrared pulse-evoked intracellular calcium signal. These results demonstrate that astrocyte function can be modulated with infrared light. We expect that targeted control over calcium dynamics and water transport will help to study the crucial role of astrocytes in edema, ischemia, glioma progression, stroke, and epilepsy.
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Affiliation(s)
- Ana I Borrachero-Conejo
- Istituto per lo Studio dei Materiali Nanostrutturati, Consiglio Nazionale delle Ricerche, Bologna, Italy
| | - Wilson R Adams
- Department Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
- Vanderbilt Biophotonics Center, Vanderbilt University, Nashville, TN, USA
| | - Emanuela Saracino
- Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche, Bologna, Italy
| | - Maria Grazia Mola
- Department of Bioscience, Biotechnology and Biopharmaceutics and Centre of Excellence in Comparative Genomics, University of Bari Aldo Moro, Bari, Italy
| | - Manqing Wang
- Vanderbilt Biophotonics Center, Vanderbilt University, Nashville, TN, USA
- Bioengineering College, Chongqing University, Chongqing, China
| | - Tamara Posati
- Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche, Bologna, Italy
| | - Francesco Formaggio
- Dipartimento di Farmacia e Biotecnologie, University of Bologna, Bologna, Italy
| | - Manuela De Bellis
- Department of Bioscience, Biotechnology and Biopharmaceutics and Centre of Excellence in Comparative Genomics, University of Bari Aldo Moro, Bari, Italy
| | - Antonio Frigeri
- Department of Basic Medical Sciences, Neuroscience and Sense Organs, School of Medicine, University of Bari Aldo Moro, Bari, Italy
- Department of Neuroscience, Albert Einstein College of Medicine, Yeshiva University, New York, NY, USA
| | - Marco Caprini
- Istituto per lo Studio dei Materiali Nanostrutturati, Consiglio Nazionale delle Ricerche, Bologna, Italy
- Dipartimento di Farmacia e Biotecnologie, University of Bologna, Bologna, Italy
| | - Mark R Hutchinson
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia
| | - Michele Muccini
- Istituto per lo Studio dei Materiali Nanostrutturati, Consiglio Nazionale delle Ricerche, Bologna, Italy
| | - Roberto Zamboni
- Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche, Bologna, Italy
| | - Grazia Paola Nicchia
- Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche, Bologna, Italy
- Department of Bioscience, Biotechnology and Biopharmaceutics and Centre of Excellence in Comparative Genomics, University of Bari Aldo Moro, Bari, Italy
- Department of Neuroscience, Albert Einstein College of Medicine, Yeshiva University, New York, NY, USA
| | - Anita Mahadevan-Jansen
- Department Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
- Vanderbilt Biophotonics Center, Vanderbilt University, Nashville, TN, USA
- Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Valentina Benfenati
- Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche, Bologna, Italy
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10
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Eom K, Hwang S, Yun S, Byun KM, Jun SB, Kim SJ. Photothermal activation of astrocyte cells using localized surface plasmon resonance of gold nanorods. JOURNAL OF BIOPHOTONICS 2017; 10:486-493. [PMID: 28164459 DOI: 10.1002/jbio.201600280] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 12/30/2016] [Accepted: 01/12/2016] [Indexed: 06/06/2023]
Abstract
Although it has been revealed that astrocytes, generally known as star-shaped glial cells, play critical roles in the functions of central nervous system, there have been few efforts to directly modulate their activities and responses. In this study, an optical stimulation strategy for producing intracellular Ca2+ transients of astrocytes is demonstrated using near-infrared (NIR) light and localized surface plasmon resonance. It is presented that NIR stimulation of micro-second duration combined with gold nanorods (GNRs) efficiently produces stronger Ca2+ transients of astrocytes, which seems to be associated with a local heat generation by photothermal effects of GNRs. Since the proposed scheme can directly activate astrocytes with a high reliability, it is expected that GNR-mediated NIR stimulation could be utilized to facilitate minimally invasive physiological studies on the astrocyte functions. Photos of intracellular Ca2+ transient of astrocytes with membrane-bound GNRs after optical stimulation at 30 s.
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Affiliation(s)
- Kyungsik Eom
- Department of Electrical and Computer Engineering, Seoul National University, Seoul, 08826, South Korea
| | - Seoyoung Hwang
- Department of Electronics Engineering, Ewha Womans University, Seoul, 03760, South Korea
| | - Seunghyeon Yun
- Department of Electrical and Computer Engineering, Seoul National University, Seoul, 08826, South Korea
| | - Kyung Min Byun
- Department of Biomedical Engineering, Kyung Hee University, Yongin, 17104, South Korea
| | - Sang Beom Jun
- Department of Electronics Engineering, Ewha Womans University, Seoul, 03760, South Korea
- Department of Brain and Cognitive Sciences, Ewha Womans University, Seoul, 03760, South Korea
| | - Sung June Kim
- Department of Electrical and Computer Engineering, Seoul National University, Seoul, 08826, South Korea
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11
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Raos BJ, Graham ES, Unsworth CP. Nanosecond UV lasers stimulate transient Ca2+elevations in human hNT astrocytes. J Neural Eng 2017; 14:035001. [DOI: 10.1088/1741-2552/aa5f27] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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12
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Raos BJ, Graham ES, Unsworth CP. Investigation of the Ca2+ response of human hNT astrocytes to laser removal of cellular processes. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2017; 2016:1750-1753. [PMID: 28268665 DOI: 10.1109/embc.2016.7591055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We demonstrate, for the first time, UV laser ablative microsurgery as a method for pruning astrocytic processes from live hNT astrocytic networks in vitro. Calcium fluorescence imaging was used to evaluate the cellular response to process ablation. The results showed that ablation of astrocyte processes induced an immediate increase in intracellular calcium level which propagated through the cells cytoplasm as a wave originating from the ablation site. The increased intracellular calcium dissipated from the body of the cell but remained high in the vicinity of the ablation site. Cell viability post ablation was confirmed by observing the integrity of the cell membrane. Ablation of astrocytic processes did not compromise cell viability whereas ablation of the cytoplasm using the same laser energy resulted in cell lysis.
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13
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Molokanova E, Mercola M, Savchenko A. Bringing new dimensions to drug discovery screening: impact of cellular stimulation technologies. Drug Discov Today 2017; 22:1045-1055. [PMID: 28179145 DOI: 10.1016/j.drudis.2017.01.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 12/09/2016] [Accepted: 01/27/2017] [Indexed: 01/08/2023]
Abstract
The current mandate for the drug discovery industry is to develop more efficient drugs faster while reducing the costs associated with their development. Incorporation of cell stimulation technologies during screening assays is expected to revolutionize the discovery of novel drugs as well as safety pharmacology. In this review, we highlight 'classical' and emerging cell stimulation technologies that provide the ability to evaluate the effects of drug candidates on cells in different functional states to assess clinically relevant phenotypes.
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Affiliation(s)
- Elena Molokanova
- Nanotools Bioscience, Encinitas, CA 92024, USA; Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Mark Mercola
- Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA 92037, USA; Department of Medicine and Cardiovascular Institute, Stanford University, Palo Alto, CA 94304, USA
| | - Alex Savchenko
- Department of Medicine and Cardiovascular Institute, Stanford University, Palo Alto, CA 94304, USA; Department of Pediatrics, University of California-San Diego, La Jolla, CA 92093, USA.
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14
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Gold nanoparticle-assisted all optical localized stimulation and monitoring of Ca²⁺ signaling in neurons. Sci Rep 2016; 6:20619. [PMID: 26857748 PMCID: PMC4746645 DOI: 10.1038/srep20619] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 01/08/2016] [Indexed: 11/21/2022] Open
Abstract
Light-assisted manipulation of cells to control membrane activity or intracellular signaling has become a major avenue in life sciences. However, the ability to perform subcellular light stimulation to investigate localized signaling has been limited. Here, we introduce an all optical method for the stimulation and the monitoring of localized Ca2+ signaling in neurons that takes advantage of plasmonic excitation of gold nanoparticles (AuNPs). We show with confocal microscopy that 800 nm laser pulse application onto a neuron decorated with a few AuNPs triggers a transient increase in free Ca2+, measured optically with GCaMP6s. We show that action potentials, measured electrophysiologically, can be induced with this approach. We demonstrate activation of local Ca2+ transients and Ca2+ signaling via CaMKII in dendritic domains, by illuminating a single or few functionalized AuNPs specifically targeting genetically-modified neurons. This NP-Assisted Localized Optical Stimulation (NALOS) provides a new complement to light-dependent methods for controlling neuronal activity and cell signaling.
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15
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Lumbreras V, Bas E, Gupta C, Rajguru SM. Pulsed infrared radiation excites cultured neonatal spiral and vestibular ganglion neurons by modulating mitochondrial calcium cycling. J Neurophysiol 2014; 112:1246-55. [PMID: 24920028 DOI: 10.1152/jn.00253.2014] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Cochlear implants are currently the most effective solution for profound sensorineural hearing loss, and vestibular prostheses are under development to treat bilateral vestibulopathies. Electrical current spread in these neuroprostheses limits channel independence and, in some cases, may impair their performance. In comparison, optical stimuli that are spatially confined may result in a significant functional improvement. Pulsed infrared radiation (IR) has previously been shown to elicit responses in neurons. This study analyzes the response of neonatal rat spiral and vestibular ganglion neurons in vitro to IR (wavelength = 1,863 nm) using Ca(2+) imaging. Both types of neurons responded consistently with robust intracellular Ca(2+) ([Ca(2+)]i) transients that matched the low-frequency IR pulses applied (4 ms, 0.25-1 pps). Radiant exposures of ∼637 mJ/cm(2) resulted in continual neuronal activation. Temperature or [Ca(2+)] variations in the media did not alter the IR-evoked transients, ruling out extracellular Ca(2+) involvement or primary mediation by thermal effects on the plasma membrane. While blockage of Na(+), K(+), and Ca(2+) plasma membrane channels did not alter the IR-evoked response, blocking of mitochondrial Ca(2+) cycling with CGP-37157 or ruthenium red reversibly inhibited the IR-evoked [Ca(2+)]i transients. Additionally, the magnitude of the IR-evoked transients was dependent on ryanodine and cyclopiazonic acid-dependent Ca(2+) release. These results suggest that IR modulation of intracellular calcium cycling contributes to stimulation of spiral and vestibular ganglion neurons. As a whole, the results suggest selective excitation of neurons in the IR beam path and the potential of IR stimulation in future auditory and vestibular prostheses.
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Affiliation(s)
- Vicente Lumbreras
- Department of Biomedical Engineering, University of Miami, Miami, Florida; and
| | - Esperanza Bas
- Department of Otolaryngology, University of Miami, Miami, Florida
| | - Chhavi Gupta
- Department of Otolaryngology, University of Miami, Miami, Florida
| | - Suhrud M Rajguru
- Department of Biomedical Engineering, University of Miami, Miami, Florida; and Department of Otolaryngology, University of Miami, Miami, Florida
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Benfenati V, Martino N, Antognazza MR, Pistone A, Toffanin S, Ferroni S, Lanzani G, Muccini M. Photostimulation of whole-cell conductance in primary rat neocortical astrocytes mediated by organic semiconducting thin films. Adv Healthc Mater 2014; 3:392-9. [PMID: 23966220 DOI: 10.1002/adhm.201300179] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Indexed: 12/19/2022]
Abstract
Astroglial ion channels are fundamental molecular targets in the study of brain physiology and pathophysiology. Novel tools and devices intended for stimulation and control of astrocytes ion channel activity are therefore highly desirable. The study of the interactions between astrocytes and biomaterials is also essential to control and minimize reactive astrogliosis, in view of the development of implantable functional devices. Here, the growth of rat primary neocortical astrocytes on the top of a light sensitive, organic polymer film is reported; by means of patch-clamp analyses, the effect of the visible light stimulation on membrane conductance is then determined. Photoexcitation of the active material causes a significant depolarization of the astroglial resting membrane potential: the effect is associated to an increase in whole-cell conductance at negative potentials. The magnitude of the evoked inward current density is proportional to the illumination intensity. Biophysical and pharmacological characterization suggests that the ion channel mediating the photo-transduction mechanism is a chloride channel, the ClC-2 channel. These results open interesting perspectives for the selective manipulation of astrocyte bioelectrical activity by non-invasive, label-free, organic-based, photostimulation approaches.
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Affiliation(s)
- Valentina Benfenati
- Consiglio Nazionale delle Ricerche (CNR), Istituto per la Sintesi Organica e la Fotoreattività (ISOF); Via Gobetti 101 40129 Bologna Italy
| | - Nicola Martino
- Center for Nanoscience and Technology @PoliMi, Istituto Italiano di Tecnologia; Via Pascoli 70/3 20133 Milano Italy
- Politecnico di Milano, Dip. di Fisica; Piazza L. Da Vinci 32 20133 Milano Italy
| | - Maria Rosa Antognazza
- Center for Nanoscience and Technology @PoliMi, Istituto Italiano di Tecnologia; Via Pascoli 70/3 20133 Milano Italy
| | - Assunta Pistone
- Consiglio Nazionale delle Ricerche (CNR), Istituto per la Sintesi Organica e la Fotoreattività (ISOF); Via Gobetti 101 40129 Bologna Italy
| | - Stefano Toffanin
- Consiglio Nazionale delle Ricerche (CNR), Istituto per lo Studio dei Materiali Nanostrutturati (ISMN); Via P. Gobetti 101 40129 Bologna Italy
| | - Stefano Ferroni
- Department of Pharmacy and Biotechnology; University of Bologna; Via S. Donato, 19/2 40127 Bologna Italy
| | - Guglielmo Lanzani
- Center for Nanoscience and Technology @PoliMi, Istituto Italiano di Tecnologia; Via Pascoli 70/3 20133 Milano Italy
- Politecnico di Milano, Dip. di Fisica; Piazza L. Da Vinci 32 20133 Milano Italy
| | - Michele Muccini
- Consiglio Nazionale delle Ricerche (CNR), Istituto per lo Studio dei Materiali Nanostrutturati (ISMN); Via P. Gobetti 101 40129 Bologna Italy
- E. T. C. s.r.l.; via P. Gobetti 101 I-40129 Bologna Italy
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17
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Chen Y, Mancuso J, Zhao Z, Li X, Cheng J, Roman G, Wong STC. Vasodilation by in vivo activation of astrocyte endfeet via two-photon calcium uncaging as a strategy to prevent brain ischemia. JOURNAL OF BIOMEDICAL OPTICS 2013; 18:126012. [PMID: 24343443 PMCID: PMC3865896 DOI: 10.1117/1.jbo.18.12.126012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 11/04/2013] [Accepted: 11/05/2013] [Indexed: 06/03/2023]
Abstract
Decreased cerebral blood flow causes brain ischemia and plays an important role in the pathophysiology of many neurodegenerative diseases, including Alzheimer's disease and vascular dementia. In this study, we photomodulated astrocytes in the live animal by a combination of two-photon calcium uncaging in the astrocyte endfoot and in vivo imaging of neurovasculature and astrocytes by intravital two-photon microscopy after labeling with cell type specific fluorescent dyes. Our study demonstrates that photomodulation at the endfoot of a single astrocyte led to a 25% increase in the diameter of a neighboring arteriole, which is a crucial factor regulating cerebral microcirculation in downstream capillaries. Two-photon uncaging in the astrocyte soma or endfoot near veins does not show the same effect on microcirculation. These experimental results suggest that infrared photomodulation on astrocyte endfeet may be a strategy to increase cerebral local microcirculation and thus prevent brain ischemia.
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Affiliation(s)
- Yuanxin Chen
- Weill Cornell Medical College, Houston Methodist Research Institute, \Systems Medicine and Bioengineering Department, TT and WF Chao Center for BRAIN, Houston, Texas 77030
| | - James Mancuso
- Weill Cornell Medical College, Houston Methodist Research Institute, \Systems Medicine and Bioengineering Department, TT and WF Chao Center for BRAIN, Houston, Texas 77030
| | - Zhen Zhao
- Weill Cornell Medical College, Houston Methodist Research Institute, \Systems Medicine and Bioengineering Department, TT and WF Chao Center for BRAIN, Houston, Texas 77030
- Southeast University, Zhongda Hospital, Medical School, Department of Radiology, Jiangsu Key Laboratory of Molecular and Functional Imaging, Nanjing 210009, China
| | - Xuping Li
- Weill Cornell Medical College, Houston Methodist Research Institute, \Systems Medicine and Bioengineering Department, TT and WF Chao Center for BRAIN, Houston, Texas 77030
| | - Jie Cheng
- Weill Cornell Medical College, Houston Methodist Research Institute, \Systems Medicine and Bioengineering Department, TT and WF Chao Center for BRAIN, Houston, Texas 77030
| | - Gustavo Roman
- Weill Cornell Medical College, Houston Methodist Hospital, Nantz National Alzheimer Center, Houston, Texas 77030
| | - Stephen T. C. Wong
- Weill Cornell Medical College, Houston Methodist Research Institute, \Systems Medicine and Bioengineering Department, TT and WF Chao Center for BRAIN, Houston, Texas 77030
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18
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Hirase H, Nikolenko V, Yuste R. Multiphoton stimulation of neurons and spines. Cold Spring Harb Protoc 2012; 2012:472-5. [PMID: 22474661 DOI: 10.1101/pdb.prot068569] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
This protocol describes an optical method to directly stimulate a neuron (i.e., without using any caged chemicals or genetic probes) using an infrared ultrafast mode-locked laser. This method can trigger action potentials in a targeted neuron when a laser beam is applied to the somatic membrane. Alternatively, it can mimic excitatory postsynaptic potentials (EPSPs) when applied to dendritic spines. The protocol has been applied successfully using juvenile (postnatal day 7-14) C57 mouse neocortical and hippocampal acute slices (∼300-µm thickness). It can be used in conjunction with slices bulk loaded with calcium indicators, such as Fura-2 AM.
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Choi M, Yoon J, Ku T, Choi K, Choi C. Label-free optical activation of astrocyte in vivo. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:075003. [PMID: 21806260 DOI: 10.1117/1.3600774] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
As the most abundant cell type in the central nervous system, astrocyte has been one of main research topics in neuroscience. Although various tools have been developed, at present, there is no tool that allows noninvasive activation of astrocyte in vivo without genetic or pharmacological perturbation. Here we report a noninvasive label-free optical method for physiological astrocyte activation in vivo using a femtosecond pulsed laser. We showed the laser stimulation robustly induced astrocytic calcium activation in vivo and further verified physiological relevance of the calcium increase by demonstrating astrocyte mediated vasodilation in the brain. This novel optical method will facilitate noninvasive physiological study on astrocyte function.
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Affiliation(s)
- Myunghwan Choi
- KAIST, Department of Bio and Brain Engineering, Cell Signaling and Bioimaging Laboratory, 335 Gwahak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
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20
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Dittami GM, Rajguru SM, Lasher RA, Hitchcock RW, Rabbitt RD. Intracellular calcium transients evoked by pulsed infrared radiation in neonatal cardiomyocytes. J Physiol 2011; 589:1295-306. [PMID: 21242257 DOI: 10.1113/jphysiol.2010.198804] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Neonatal rat ventricular cardiomyocytes were used to investigate mechanisms underlying transient changes in intracellular free Ca2+ concentration ([Ca2+]i) evoked by pulsed infrared radiation (IR, 1862 nm). Fluorescence confocal microscopy revealed IR-evoked [Ca2+]i events with each IR pulse (3-4 ms pulse⁻¹, 9.1-11.6 J cm⁻² pulse⁻¹). IR-evoked [Ca2+]i events were distinct from the relatively large spontaneous [Ca2+]i transients, with IR-evoked events exhibiting smaller amplitudes (0.88 ΔF/F0 vs. 1.99 ΔF/F0) and shorter time constants (τ =0.64 s vs. 1.19 s, respectively). Both IR-evoked [Ca2+]i events and spontaneous [Ca2+]i transients could be entrained by the IR pulse (0.2-1 pulse s⁻¹), provided the IR dose was sufficient and the radiation was applied directly to the cell. Examination of IR-evoked events during peak spontaneous [Ca2+]i periods revealed a rapid drop in [Ca2+]i, often restoring the baseline [Ca2+]i concentration, followed by a transient increase in [Ca2+]i.Cardiomyocytes were challenged with pharmacological agents to examine potential contributors to the IR-evoked [Ca2+]i events. Three compounds proved to be the most potent, reversible inhibitors: (1) CGP-37157 (20 μM, n =12), an inhibitor of the mitochondrial Na+/Ca2+ exchanger (mNCX), (2) Ruthenium Red (40 μM, n =13), an inhibitor of the mitochondrial Ca2+ uniporter (mCU), and (3) 2-aminoethoxydiphenylborane (10 μM, n =6), an IP3 channel antagonist. Ryanodine blocked the spontaneous [Ca2+]i transients but did not alter the IR-evoked events in the same cells. This pharmacological array implicates mitochondria as the major intracellular store of Ca2+ involved in IR-evoked responses reported here. Results support the hypothesis that 1862 nm pulsed IR modulates mitochondrial Ca2+ transport primarily through actions on mCU and mNCX.
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Affiliation(s)
- Gregory M Dittami
- Department of Bioengineering, University of Utah, Salt Lake City, UT 84112, USA.
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21
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Modulation of synchronous calcium oscillations in hippocampal neurons by photostimulation of astrocytes with femtosecond laser. CHINESE SCIENCE BULLETIN-CHINESE 2010. [DOI: 10.1007/s11434-010-3376-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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22
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He H, Kong SK, Chan KT. Identification of source of calcium in HeLa cells by femtosecond laser excitation. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:057010. [PMID: 21054126 DOI: 10.1117/1.3485741] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Calcium is an important messenger in cells and whose store and diffusion dynamics at the subcellular level remain unclear. By inducing a controlled slow subcellular Ca2+ release through femtosecond laser irradiation in HeLa cells immersed in different media, cytoplasm is identified to be the major intracellular Ca2+ store, with the nucleus being the minor store and the extracellular Ca2+ also contributing to the total cellular Ca2+ level. Furthermore, Ca2+ released in either the cytoplasm or nucleus diffuses into the nucleus or cytoplasm, respectively, at different rates and influences the Ca2+ release in those regions.
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Affiliation(s)
- Hao He
- Chinese University of Hong Kong, Department of Electronic Engineering, Hong Kong
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23
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Zhao Y, Zhang Y, Zhou W, Liu X, Zeng S, Luo Q. Characteristics of calcium signaling in astrocytes induced by photostimulation with femtosecond laser. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:035001. [PMID: 20615001 DOI: 10.1117/1.3454390] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Astrocytes have been identified to actively contribute to brain functions through Ca(2+) signaling, serving as a bridge to communicate with neurons and other brain cells. However, conventional stimulation techniques are hard to apply to delicate investigations on astrocytes. Our group previously reported photostimulation with a femtosecond laser to evoke astrocytic calcium (Ca(2+)) waves, providing a noninvasive and efficient approach with highly precise targeting. In this work, detailed characteristics of astrocytic Ca(2+) signaling induced by photostimulation are presented. In a purified astrocytic culture, after the illumination of a femtosecond laser onto one cell, a Ca(2+) wave throughout the network with reduced speed is induced, and intracellular Ca(2+) oscillations are observed. The intercellular propagation is pharmacologically confirmed to be mainly mediated by ATP through P(2)Y receptors. Different patterns of Ca(2+) elevations with increased amplitude in the stimulated astrocyte are discovered by varying the femtosecond laser power, which is correspondingly followed by broader intercellular waves. These indicate that the strength of photogenerated Ca(2+) signaling in astrocytes has a positive relationship with the stimulating laser power. Therefore, distinct Ca(2+) signaling is feasibly available for specific studies on astrocytes by employing precisely controlled photostimulation.
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Affiliation(s)
- Yuan Zhao
- Huazhong University of Science and Technology, Wuhan National Laboratory for Optoelectronics, Britton Chance Center for Biomedical Photonics, Wuhan 430074, China
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24
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Parys B, Côté A, Gallo V, De Koninck P, Sík A. Intercellular calcium signaling between astrocytes and oligodendrocytes via gap junctions in culture. Neuroscience 2010; 167:1032-43. [PMID: 20211698 DOI: 10.1016/j.neuroscience.2010.03.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Revised: 02/23/2010] [Accepted: 03/02/2010] [Indexed: 11/16/2022]
Abstract
To understand further how oligodendrocytes regulate brain function, the mechanism of communication between oligodendrocytes and other cell types needs to be explored. An important mode of communication between various cell types in the nervous system involves gap junctions. Astroglial cells are extensively connected through gap junctions forming the glial syncytium. Although the presence of gap junctions between oligodendrocytes and astrocytes have been well documented, evidence for gap junction-mediated calcium transfer between these two glial populations is still missing. To measure functional coupling between astrocytes and oligodendrocytes and to test whether this coupling is mediated by gap junctions we used laser photostimulation and monitored Ca(2+) propagation in cultures from transgenic animals in which oligodendrocytes express enhanced green fluorescent protein (eGFP). We show that waves of Ca(2+) spread from astrocytes to oligodendrocytes and that these waves are blocked by the broad-spectrum gap junction blocker carbenoxolone, but not the neuron-specific gap junction blocker quinine. We also show that the spread of Ca(2+) waves between astrocytes and oligodendrocytes is bi-directional. Thus, increase of Ca(2+) concentration in astrocytes triggered by surrounding neuronal activity may feed back onto different neuronal populations through oligodendrocytes.
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Affiliation(s)
- B Parys
- Centre de Recherche Université Laval Robert-Giffard; 2601, chemin de la Canardière, Quebec, QC, G1J 2G3 Canada
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25
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Photomedicine and LLLT Literature Watch. Photomed Laser Surg 2009; 27:377-8. [DOI: 10.1089/pho.2009.9954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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