1
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Tomagra G, Re A, Varzi V, Aprà P, Britel A, Franchino C, Sturari S, Amine NH, Westerink RHS, Carabelli V, Picollo F. Enhancing the Study of Quantal Exocytotic Events: Combining Diamond Multi-Electrode Arrays with Amperometric PEak Analysis (APE) an Automated Analysis Code. BIOSENSORS 2023; 13:1033. [PMID: 38131793 PMCID: PMC10741388 DOI: 10.3390/bios13121033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 12/11/2023] [Accepted: 12/14/2023] [Indexed: 12/23/2023]
Abstract
MicroGraphited-Diamond-Multi Electrode Arrays (μG-D-MEAs) can be successfully used to reveal, in real time, quantal exocytotic events occurring from many individual neurosecretory cells and/or from many neurons within a network. As μG-D-MEAs arrays are patterned with up to 16 sensing microelectrodes, each of them recording large amounts of data revealing the exocytotic activity, the aim of this work was to support an adequate analysis code to speed up the signal detection. The cutting-edge technology of microGraphited-Diamond-Multi Electrode Arrays (μG-D-MEAs) has been implemented with an automated analysis code (APE, Amperometric Peak Analysis) developed using Matlab R2022a software to provide easy and accurate detection of amperometric spike parameters, including the analysis of the pre-spike foot that sometimes precedes the complete fusion pore dilatation. Data have been acquired from cultured PC12 cells, either collecting events during spontaneous exocytosis or after L-DOPA incubation. Validation of the APE code was performed by comparing the acquired spike parameters with those obtained using Quanta Analysis (Igor macro) by Mosharov et al.
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Affiliation(s)
- Giulia Tomagra
- Department of Drug and Science Technology, NIS Interdepartmental Centre, University of Torino, Corso Raffaello 30, 10125 Torino, Italy; (G.T.); (C.F.); (V.C.)
| | - Alice Re
- Department of Physics, NIS Interdepartmental Centre, University of Torino and Italian Institute of Nuclear Physics, Via Giuria 1, 10125 Torino, Italy (P.A.); (A.B.); (S.S.); (N.-H.A.); (F.P.)
| | - Veronica Varzi
- Department of Physics, NIS Interdepartmental Centre, University of Torino and Italian Institute of Nuclear Physics, Via Giuria 1, 10125 Torino, Italy (P.A.); (A.B.); (S.S.); (N.-H.A.); (F.P.)
| | - Pietro Aprà
- Department of Physics, NIS Interdepartmental Centre, University of Torino and Italian Institute of Nuclear Physics, Via Giuria 1, 10125 Torino, Italy (P.A.); (A.B.); (S.S.); (N.-H.A.); (F.P.)
| | - Adam Britel
- Department of Physics, NIS Interdepartmental Centre, University of Torino and Italian Institute of Nuclear Physics, Via Giuria 1, 10125 Torino, Italy (P.A.); (A.B.); (S.S.); (N.-H.A.); (F.P.)
| | - Claudio Franchino
- Department of Drug and Science Technology, NIS Interdepartmental Centre, University of Torino, Corso Raffaello 30, 10125 Torino, Italy; (G.T.); (C.F.); (V.C.)
| | - Sofia Sturari
- Department of Physics, NIS Interdepartmental Centre, University of Torino and Italian Institute of Nuclear Physics, Via Giuria 1, 10125 Torino, Italy (P.A.); (A.B.); (S.S.); (N.-H.A.); (F.P.)
| | - Nour-Hanne Amine
- Department of Physics, NIS Interdepartmental Centre, University of Torino and Italian Institute of Nuclear Physics, Via Giuria 1, 10125 Torino, Italy (P.A.); (A.B.); (S.S.); (N.-H.A.); (F.P.)
| | - Remco H. S. Westerink
- Neurotoxicology Research Group, Division of Toxicology, Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, P.O. Box 80.177, NL-3508 TD Utrecht, The Netherlands;
| | - Valentina Carabelli
- Department of Drug and Science Technology, NIS Interdepartmental Centre, University of Torino, Corso Raffaello 30, 10125 Torino, Italy; (G.T.); (C.F.); (V.C.)
| | - Federico Picollo
- Department of Physics, NIS Interdepartmental Centre, University of Torino and Italian Institute of Nuclear Physics, Via Giuria 1, 10125 Torino, Italy (P.A.); (A.B.); (S.S.); (N.-H.A.); (F.P.)
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2
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Gonçalves PP, Stenovec M, Grácio L, Kreft M, Zorec R. Calcium-dependent subquantal peptide release from single docked lawn-resident vesicles of pituitary lactotrophs. Cell Calcium 2023; 109:102687. [PMID: 36528978 DOI: 10.1016/j.ceca.2022.102687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 12/08/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022]
Abstract
Regulated exocytosis consists of the fusion between vesicles and the plasma membranes, leading to the formation of a narrow fusion pore through which secretions exit the vesicle lumen into the extracellular space. An increase in the cytosolic concentration of free Ca2+ ([Ca2+]i) is considered the stimulus of this process. However, whether this mechanism can be preserved in a simplified system of membrane lawns with docked secretory vesicles, devoid of cellular components, is poorly understood. Here, we studied peptide discharge from individual secretory vesicles docked at the plasma membrane, prepared from primary endocrine pituitary cells (the lactotrophs), releasing hormone prolactin. To label secretory vesicles, we transfected lactotrophs to express the fluorescent atrial natriuretic peptide (ANP.emd), previously shown to be expressed in and released from prolactin-containing vesicles. We used stimulating solutions containing different [Ca2+] to evoke vesicle peptide discharge, which appeared similar in membrane lawns and in intact stimulated lactotrophs. All vesicles examined discharged peptides in a subquantal manner, either exhibiting a unitary or sequential time course. In the membrane lawns, the unitary vesicle peptide discharge was predominant and slightly slower than that recorded in intact cells, but with a shorter delay with respect to the stimulation onset. This study revealed directly that Ca2+ triggers peptide discharge from docked single vesicles in the membrane lawns with a half-maximal response of ∼8 µM [Ca2+], consistent with previous whole-cell patch-clamp studies in endocrine cells where the rapid component of exocytosis, interpreted to represent docked vesicles, was fully activated at <10 µM [Ca2+]. Interestingly, the sequential subquantal peptide vesicle discharge indicates that fluctuations between constricted and dilated fusion pore states are preserved in membrane lawns and that fusion pore regulation appears to be an autonomously controlled process.
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Affiliation(s)
- Paula P Gonçalves
- CESAM - Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal
| | - Matjaž Stenovec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Zaloška 4, 1000, Ljubljana, Slovenia; Laboratory of Cell Engineering, Celica Biomedical, Tehnološki Park 24, 1000, Ljubljana, Slovenia
| | - Luciano Grácio
- CRACS & INESC-TEC - Centre for Research in Advanced Computing Systems & Institute for Systems and Computer Engineering, Technology and Science, Department of Computer Science, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
| | - Marko Kreft
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Zaloška 4, 1000, Ljubljana, Slovenia; Laboratory of Cell Engineering, Celica Biomedical, Tehnološki Park 24, 1000, Ljubljana, Slovenia; Department of Biology, University of Ljubljana, Biotechnical Faculty, 1000 Ljubljana, Slovenia
| | - Robert Zorec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Zaloška 4, 1000, Ljubljana, Slovenia; Laboratory of Cell Engineering, Celica Biomedical, Tehnološki Park 24, 1000, Ljubljana, Slovenia.
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3
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Houy S, Streit L, Drissa I, Rame M, Decraene C, Moog S, Brunaud L, Lanoix J, Chelbi R, Bihain F, Lacomme S, Lomazzi S, Campoli P, Vix M, Mutter D, Paramithiotis E, Dubessy C, Vitale N, Ory S, Gasman S. Dysfunction of calcium-regulated exocytosis at a single-cell level causes catecholamine hypersecretion in patients with pheochromocytoma. Cancer Lett 2022; 543:215765. [PMID: 35680072 DOI: 10.1016/j.canlet.2022.215765] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Revised: 05/13/2022] [Accepted: 05/28/2022] [Indexed: 11/27/2022]
Abstract
Neuroendocrine tumors constitute a heterogeneous group of tumors arising from hormone-secreting cells and are generally associated with a dysfunction of secretion. Pheochromocytoma (Pheo) is a neuroendocrine tumor that develops from chromaffin cells of the adrenal medulla, and is responsible for an excess of catecholamine secretion leading to severe clinical symptoms such as hypertension, elevated stroke risk and various cardiovascular complications. Surprisingly, while the hypersecretory activity of Pheo is well known to pathologists and clinicians, it has never been carefully explored at the cellular and molecular levels. In the present study, we have combined catecholamine secretion measurement by carbon fiber amperometry on human tumor cells directly cultured from freshly resected Pheos, with the analysis by mass spectrometry of the exocytotic proteins differentially expressed between the tumor and the matched adjacent non-tumor tissue. In most patients, catecholamine secretion recordings from single Pheo cells revealed a higher number of exocytic events per cell associated with faster kinetic parameters. Accordingly, we unravel significant tumor-associated modifications in the expression of key proteins involved in different steps of the calcium-regulated exocytic pathway. Altogether, our findings indicate that dysfunction of the calcium-regulated exocytosis at the level of individual Pheo cell is a cause of the tumor-associated hypersecretion of catecholamines.
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Affiliation(s)
- Sébastien Houy
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, F-67000, Strasbourg, France
| | - Laura Streit
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, F-67000, Strasbourg, France
| | - Inès Drissa
- Univ. Rouen, INSERM, Normandie Univ., Différenciation et Communication Neuroendocrine, Endocrine et Germinale, F-76000, Rouen, France
| | - Marion Rame
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, F-67000, Strasbourg, France
| | - Charles Decraene
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, F-67000, Strasbourg, France; Centre National de la Recherche Scientifique, Université de Strasbourg, Laboratoire de Neurosciences Cognitives et Adaptatives, F-67000 Strasbourg, France
| | - Sophie Moog
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, F-67000, Strasbourg, France
| | - Laurent Brunaud
- Département de Chirurgie Viscérale, Métabolique et Cancérologique (CVMC), INSERM NGERE-U1256, Université de Lorraine, CHRU NANCY, Hôpital Brabois adultes, F-54511, Vandœuvre-lès-Nancy, France
| | - Joël Lanoix
- Institut de Recherche en Immunologie et en Cancérologie (IRIC), Université de Montréal, Montréal, Canada, Département de Médecine, Université de Montréal, Montréal, QC H3C 3J7, Canada
| | - Rabie Chelbi
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, F-67000, Strasbourg, France; Inovarion, F-75005, Paris, France
| | - Florence Bihain
- Département de Chirurgie Viscérale, Métabolique et Cancérologique (CVMC), INSERM NGERE-U1256, Université de Lorraine, CHRU NANCY, Hôpital Brabois adultes, F-54511, Vandœuvre-lès-Nancy, France
| | - Stéphanie Lacomme
- Centre de Ressources Biologiques Lorrain, CHRU Nancy, Hôpitaux de Brabois, F-54511, Vandœuvre-lès-Nancy, France
| | - Sandra Lomazzi
- Centre de Ressources Biologiques Lorrain, CHRU Nancy, Hôpitaux de Brabois, F-54511, Vandœuvre-lès-Nancy, France
| | - Philippe Campoli
- Department of Biopathology, CHRU-ICL, CHRU Nancy, Vandoeuvre-lès-Nancy, France and Faculty of Medicine, Université de Lorraine, F-54511, Vandoeuvre-lès-Nancy, France
| | - Michel Vix
- NHC Strasbourg, Service de Chirurgie Digestive et Endocrinienne des Hôpitaux Universitaires de Strasbourg, Hôpital Civil, F-67000, Strasbourg, France
| | - Didier Mutter
- NHC Strasbourg, Service de Chirurgie Digestive et Endocrinienne des Hôpitaux Universitaires de Strasbourg, Hôpital Civil, F-67000, Strasbourg, France
| | | | - Christophe Dubessy
- Univ. Rouen, INSERM, Normandie Univ., Différenciation et Communication Neuroendocrine, Endocrine et Germinale, F-76000, Rouen, France; Univ. Rouen, INSERM, CNRS, HERACLES, PRIMACEN, F-76000, Rouen, France
| | - Nicolas Vitale
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, F-67000, Strasbourg, France
| | - Stéphane Ory
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, F-67000, Strasbourg, France
| | - Stéphane Gasman
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, F-67000, Strasbourg, France.
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4
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Chang CW, Hsiao YT, Scheuer KS, Jackson MB. Full-Fusion and Kiss-and-Run in Chromaffin Cells controlled by Irreversible Vesicle Size-Dependent Fusion Pore Transitions. Cell Calcium 2022; 105:102606. [DOI: 10.1016/j.ceca.2022.102606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 05/18/2022] [Indexed: 11/02/2022]
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5
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CMOS Perceptron for Vesicle Fusion Classification. ELECTRONICS 2022. [DOI: 10.3390/electronics11060843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Edge computing (processing data close to its source) is one of the fastest developing areas of modern electronics and hardware information technology. This paper presents the implementation process of an analog CMOS preprocessor for use in a distributed environment for processing medical data close to the source. The task of the circuit is to analyze signals of vesicle fusion, which is the basis of life processes in multicellular organisms. The functionality of the preprocessor is based on a classifier of full and partial fusions. The preprocessor is dedicated to operate in amperometric systems, and the analyzed signals are data from carbon nanotube electrodes. The accuracy of the classifier is at the level of 93.67%. The implementation was performed in the 65 nm CMOS technology with a 0.3 V power supply. The circuit operates in the weak-inversion mode and is dedicated to be powered by thermal cells of the human energy harvesting class. The maximum power consumption of the circuit equals 416 nW, which makes it possible to use it as an implantable chip. The results can be used, among others, in the diagnosis of precancerous conditions.
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6
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Szczęsny S, Pietrzak P. Exocytotic vesicle fusion classification for early disease diagnosis using a mobile GPU microsystem. Neural Comput Appl 2022. [DOI: 10.1007/s00521-021-06676-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
AbstractThis work addresses monitoring vesicle fusions occurring during the exocytosis process, which is the main way of intercellular communication. Certain vesicle behaviors may also indicate certain precancerous conditions in cells. For this purpose we designed a system able to detect two main types of exocytosis: a full fusion and a kiss-and-run fusion, based on data from multiple amperometric sensors at once. It uses many instances of small perceptron neural networks in a massively parallel manner and runs on Jetson TX2 platform, which uses a GPU for parallel processing. Based on performed benchmarking, approximately 140,000 sensors can be processed in real time within the sensor sampling period equal to 10 ms and an accuracy of 99$$\%$$
%
. The work includes an analysis of the system performance with varying neural network sizes, input data sizes, and sampling periods of fusion signals.
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7
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Bouret Y, Guille-Collignon M, Lemaître F. Simulations of amperometric monitoring of exocytosis: moderate pH variations within the cell-electrode cleft with the buffer diffusion. Anal Bioanal Chem 2021; 413:6769-6776. [PMID: 34120197 DOI: 10.1007/s00216-021-03443-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 05/28/2021] [Indexed: 10/21/2022]
Abstract
Amperometry with ultramicroelectrodes is nowadays a routine technique to investigate neurotransmitter secretion by vesicular exocytosis at the single-cell level. This electroanalytical tool allows one to understand many aspects of the vesicular release in terms of mechanisms. However, the electrochemical detection relies on the oxidation of released neurotransmitters that produce 2H+ and thus the possible acidification of the cell-electrode cleft. In a previous work, we considered a model involving the H+ diffusion or/and its reaction with buffer species. In this article, we report a more general model which takes into account the ability of buffer species to move and to be regenerated within the cell-electrode cleft. As a consequence, the pH within the cleft is still equal to its physiological value regardless of the electrochemical detection of the vesicular release for usual exocytotic cell frequencies. This confirms that amperometry at the single-cell level is a very robust technique for investigating vesicular exocytosis.
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Affiliation(s)
- Yann Bouret
- CNRS-UMR 7010 Institut de Physique de Nice, Université Nice Côte d'Azur, Av. Joseph Vallot, 06100, Nice, France
| | - Manon Guille-Collignon
- PASTEUR, Département de chimie, École normale supérieure, PSL University, Sorbonne Université, CNRS, 75005, Paris, France
| | - Frédéric Lemaître
- PASTEUR, Département de chimie, École normale supérieure, PSL University, Sorbonne Université, CNRS, 75005, Paris, France.
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8
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Spiking Neural Network with Linear Computational Complexity for Waveform Analysis in Amperometry. SENSORS 2021; 21:s21093276. [PMID: 34068538 PMCID: PMC8125990 DOI: 10.3390/s21093276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/03/2021] [Accepted: 05/08/2021] [Indexed: 11/17/2022]
Abstract
The paper describes the architecture of a Spiking Neural Network (SNN) for time waveform analyses using edge computing. The network model was based on the principles of preprocessing signals in the diencephalon and using tonic spiking and inhibition-induced spiking models typical for the thalamus area. The research focused on a significant reduction of the complexity of the SNN algorithm by eliminating most synaptic connections and ensuring zero dispersion of weight values concerning connections between neuron layers. The paper describes a network mapping and learning algorithm, in which the number of variables in the learning process is linearly dependent on the size of the patterns. The works included testing the stability of the accuracy parameter for various network sizes. The described approach used the ability of spiking neurons to process currents of less than 100 pA, typical of amperometric techniques. An example of a practical application is an analysis of vesicle fusion signals using an amperometric system based on Carbon NanoTube (CNT) sensors. The paper concludes with a discussion of the costs of implementing the network as a semiconductor structure.
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9
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Houy S, Martins JS, Mohrmann R, Sørensen JB. Measurements of Exocytosis by Capacitance Recordings and Calcium Uncaging in Mouse Adrenal Chromaffin Cells. Methods Mol Biol 2021; 2233:233-251. [PMID: 33222139 DOI: 10.1007/978-1-0716-1044-2_16] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Fusion of vesicles with the plasma membrane and liberation of their contents is a multistep process involving several proteins. Correctly assigning the role of specific proteins and reactions in this cascade requires a measurement method with high temporal resolution. Patch-clamp recordings of cell membrane capacitance in combination with calcium measurements, calcium uncaging, and carbon-fiber amperometry allow for the accurate determination of vesicle pool sizes, their fusion kinetics, and their secreted oxidizable content. Here, we will describe this method in a model system for neurosecretion, the adrenal chromaffin cells, which secrete adrenaline.
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Affiliation(s)
- Sébastien Houy
- Department of Neuroscience, University of Copenhagen, Copenhagen N, Denmark
| | - Joana S Martins
- Department of Neuroscience, University of Copenhagen, Copenhagen N, Denmark
| | - Ralf Mohrmann
- Institute for Physiology, Otto-von-Guericke University, Magdeburg, Germany
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10
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Guille-Collignon M, Lemaître F. Overview and outlook of the strategies devoted to electrofluorescence surveys: Application to single cell secretion analysis. Trends Analyt Chem 2020. [DOI: 10.1016/j.trac.2020.116055] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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11
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Mono- and Poly-unsaturated Phosphatidic Acid Regulate Distinct Steps of Regulated Exocytosis in Neuroendocrine Cells. Cell Rep 2020; 32:108026. [DOI: 10.1016/j.celrep.2020.108026] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 06/16/2020] [Accepted: 07/21/2020] [Indexed: 12/21/2022] Open
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12
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Lebègue E, Barrière F, Bard AJ. Lipid Membrane Permeability of Synthetic Redox DMPC Liposomes Investigated by Single Electrochemical Collisions. Anal Chem 2020; 92:2401-2408. [DOI: 10.1021/acs.analchem.9b02809] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Estelle Lebègue
- Université de Nantes, CNRS, CEISAM UMR 6230, F-44000 Nantes, France
| | - Frédéric Barrière
- Univ Rennes, CNRS, Institut des Sciences Chimiques de Rennes - UMR 6226, F-35000 Rennes, France
| | - Allen J. Bard
- Center for Electrochemistry, Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
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13
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Sangsiri S, Xu H, Fernandes R, Fink GD, Lujan HL, DiCarlo SE, Galligan JJ. Spinal cord injury alters purinergic neurotransmission to mesenteric arteries in rats. Am J Physiol Heart Circ Physiol 2019; 318:H223-H237. [PMID: 31774690 DOI: 10.1152/ajpheart.00525.2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Complications associated with spinal cord injury (SCI) result from unregulated reflexes below the lesion level. Understanding neurotransmission distal to the SCI could improve quality of life by mitigating complications. The long-term impact of SCI on neurovascular transmission is poorly understood, but reduced sympathetic activity below the site of SCI enhances arterial neurotransmission (1). We studied sympathetic neurovascular transmission using a rat model of long-term paraplegia (T2-3) and tetraplegia (C6-7). Sixteen weeks after SCI, T2-3 and C6-7 rats had lower blood pressure (BP) than sham rats (103 ± 2 and 97 ± 4 vs. 117 ± 6 mmHg, P < 0.05). T2-3 rats had tachycardia (410 ± 6 beats/min), and C6-7 rats had bradycardia (299 ± 10 beats/min) compared with intact rats (321 ± 4 beats/min, P < 0.05). Purinergic excitatory junction potentials (EJPs) were measured in mesenteric arteries (MA) using microlectrodes, and norepinephrine (NE) release was measured using amperometry. NE release was similar in all groups, while EJP frequency-response curves from T2-3 and C6-7 rats were left-shifted vs. sham rats. EJPs in T2-3 and C6-7 rats showed facilitation followed by run-down during stimulation trains (10 Hz, 50 stimuli). MA reactivity to exogenous NE and ATP was similar in all rats. In T2-3 and C6-7 rats, NE content was increased in left cardiac ventricles compared with intact rats, but was not changed in MA, kidney, or spleen. Our data indicate that peripheral purinergic, but not adrenergic, neurotransmission increases following SCI via enhanced ATP release from periarterial nerves. Sympathetic BP support is reduced after SCI, but improving neurotransmitter release might maintain cardiovascular stability in individuals living with SCI.NEW & NOTEWORTHY This study revealed increased purinergic, but not noradrenergic, neurotransmission to mesenteric arteries in rats with spinal cord injury (SCI). An increased releasable pool of ATP in periarterial sympathetic nerves may contribute to autonomic dysreflexia following SCI, suggesting that purinergic neurotransmission may be a therapeutic target for maintaining stable blood pressure in individuals living with SCI. The selective increase in ATP release suggests that ATP and norepinephrine may be stored in separate synaptic vesicles in periarterial sympathetic varicosities.
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Affiliation(s)
- Sutheera Sangsiri
- Department of Preclinical Science, Thammasat University, Pathumthani, Thailand.,Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan
| | - Hui Xu
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan.,Neuroscience Program, Michigan State University, East Lansing, Michigan
| | - Roxanne Fernandes
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan
| | - Greg D Fink
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan.,Neuroscience Program, Michigan State University, East Lansing, Michigan
| | - Heidi L Lujan
- Department of Physiology, Michigan State University, East Lansing, Michigan
| | - Stephen E DiCarlo
- Department of Physiology, Michigan State University, East Lansing, Michigan
| | - James J Galligan
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan.,Neuroscience Program, Michigan State University, East Lansing, Michigan
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14
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Liu X, Tong Y, Fang PP. Recent development in amperometric measurements of vesicular exocytosis. Trends Analyt Chem 2019. [DOI: 10.1016/j.trac.2019.01.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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15
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Conzuelo F, Schulte A, Schuhmann W. Biological imaging with scanning electrochemical microscopy. Proc Math Phys Eng Sci 2018; 474:20180409. [PMID: 30839832 PMCID: PMC6237495 DOI: 10.1098/rspa.2018.0409] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Accepted: 09/04/2018] [Indexed: 12/27/2022] Open
Abstract
Scanning electrochemical microscopy (SECM) is a powerful and versatile technique for visualizing the local electrochemical activity of a surface as an ultramicroelectrode tip is moved towards or over a sample of interest using precise positioning systems. In comparison with other scanning probe techniques, SECM not only enables topographical surface mapping but also gathers chemical information with high spatial resolution. Considerable progress has been made in the analysis of biological samples, including living cells and immobilized biomacromolecules such as enzymes, antibodies and DNA fragments. Moreover, combinations of SECM with comple-mentary analytical tools broadened its applicability and facilitated multi-functional analysis with extended life science capabilities. The aim of this review is to present a brief topical overview on recent applications of biological SECM, with particular emphasis on important technical improvements of this surface imaging technique, recommended applications and future trends.
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Affiliation(s)
- Felipe Conzuelo
- Analytical Chemistry—Center for Electrochemical Sciences (CES), Faculty for Chemistry and Biochemistry, Ruhr-Universität Bochum, Universitätsstr. 150, 44780 Bochum, Germany
| | - Albert Schulte
- School of Biomolecular Science and Engineering (BSE), Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong 21210, Thailand
| | - Wolfgang Schuhmann
- Analytical Chemistry—Center for Electrochemical Sciences (CES), Faculty for Chemistry and Biochemistry, Ruhr-Universität Bochum, Universitätsstr. 150, 44780 Bochum, Germany
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16
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Eßmann V, Santana Santos C, Tarnev T, Bertotti M, Schuhmann W. Scanning Bipolar Electrochemical Microscopy. Anal Chem 2018; 90:6267-6274. [DOI: 10.1021/acs.analchem.8b00928] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Vera Eßmann
- Analytical Chemistry − Center for Electrochemical Sciences (CES), Ruhr-Universität Bochum, Universitätßtrasse 150, D-44780 Bochum, Germany
| | - Carla Santana Santos
- Analytical Chemistry − Center for Electrochemical Sciences (CES), Ruhr-Universität Bochum, Universitätßtrasse 150, D-44780 Bochum, Germany
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Professor Lineu Prestes, 748 05513-970, São Paulo, Brazil
| | - Tsvetan Tarnev
- Analytical Chemistry − Center for Electrochemical Sciences (CES), Ruhr-Universität Bochum, Universitätßtrasse 150, D-44780 Bochum, Germany
| | - Mauro Bertotti
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Professor Lineu Prestes, 748 05513-970, São Paulo, Brazil
| | - Wolfgang Schuhmann
- Analytical Chemistry − Center for Electrochemical Sciences (CES), Ruhr-Universität Bochum, Universitätßtrasse 150, D-44780 Bochum, Germany
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