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Stuber A, Cavaccini A, Manole A, Burdina A, Massoud Y, Patriarchi T, Karayannis T, Nakatsuka N. Interfacing Aptamer-Modified Nanopipettes with Neuronal Media and Ex Vivo Brain Tissue. ACS MEASUREMENT SCIENCE AU 2024; 4:92-103. [PMID: 38404490 PMCID: PMC10885324 DOI: 10.1021/acsmeasuresciau.3c00047] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 10/31/2023] [Accepted: 11/01/2023] [Indexed: 02/27/2024]
Abstract
Aptamer-functionalized biosensors exhibit high selectivity for monitoring neurotransmitters in complex environments. We translated nanoscale aptamer-modified nanopipette sensors to detect endogenous dopamine release in vitro and ex vivo. These sensors employ quartz nanopipettes with nanoscale pores (ca. 10 nm diameter) that are functionalized with aptamers that enable the selective capture of dopamine through target-specific conformational changes. The dynamic behavior of aptamer structures upon dopamine binding leads to the rearrangement of surface charge within the nanopore, resulting in measurable changes in ionic current. To assess sensor performance in real time, we designed a fluidic platform to characterize the temporal dynamics of nanopipette sensors. We then conducted differential biosensing by deploying control sensors modified with nonspecific DNA alongside dopamine-specific sensors in biological milieu. Our results confirm the functionality of aptamer-modified nanopipettes for direct measurements in undiluted complex fluids, specifically in the culture media of human-induced pluripotent stem cell-derived dopaminergic neurons. Moreover, sensor implantation and repeated measurements in acute brain slices was possible, likely owing to the protected sensing area inside nanoscale DNA-filled orifices, minimizing exposure to nonspecific interferents and preventing clogging. Further, differential recordings of endogenous dopamine released through electrical stimulation in the dorsolateral striatum demonstrate the potential of aptamer-modified nanopipettes for ex vivo recordings with unprecedented spatial resolution and reduced tissue damage.
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Affiliation(s)
- Annina Stuber
- Laboratory
of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zürich, Zurich CH-8092, Switzerland
| | - Anna Cavaccini
- Laboratory
of Neural Circuit Assembly, Brain Research Institute, University of Zurich, Zurich CH-8057, Switzerland
- Neuroscience
Center Zurich, University and ETH Zurich, Zurich CH-8057, Switzerland
| | - Andreea Manole
- iXCells
Biotechnologies, Inc., San Diego, California 92131, United States
| | - Anna Burdina
- Laboratory
of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zürich, Zurich CH-8092, Switzerland
| | - Yassine Massoud
- Laboratory
of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zürich, Zurich CH-8092, Switzerland
| | - Tommaso Patriarchi
- Neuroscience
Center Zurich, University and ETH Zurich, Zurich CH-8057, Switzerland
- Institute
of Pharmacology and Toxicology, University
of Zurich, Zurich CH-8057, Switzerland
| | - Theofanis Karayannis
- Laboratory
of Neural Circuit Assembly, Brain Research Institute, University of Zurich, Zurich CH-8057, Switzerland
- Neuroscience
Center Zurich, University and ETH Zurich, Zurich CH-8057, Switzerland
| | - Nako Nakatsuka
- Laboratory
of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zürich, Zurich CH-8092, Switzerland
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Mahabir S, Chatterjee D, Gerlai R. Short exposure to low concentrations of alcohol during embryonic development has only subtle and strain- dependent effect on the levels of five amino acid neurotransmitters in zebrafish. Neurotoxicol Teratol 2018; 68:91-96. [PMID: 29886245 DOI: 10.1016/j.ntt.2018.05.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 05/30/2018] [Accepted: 05/31/2018] [Indexed: 12/21/2022]
Abstract
The zebrafish has been successfully employed to model and study the effects of embryonic alcohol exposure. Short exposure to low alcohol concentrations during embryonic development has been shown to significantly disrupt social behavior as well as the dopaminergic and serotoninergic systems in zebrafish. However, analysis of potential effects of embryonic alcohol exposure on other amino acid neurotransmitter systems has not been performed. Here we analyzed neurochemicals obtained from adult AB and TU strain zebrafish that were immersed in 0.00% (control), 0.25%, 0.50%, 0.75% or 1.00% alcohol solution (vol/vol%) at 24 h post-fertilization for 2 h. From whole brain extracts, we quantified glutamate, aspartate, glycine, taurine and GABA levels using high performance liquid chromatography (HPLC). We found embryonic alcohol exposure not to have any significant effect on the levels of glutamate, aspartate, glycine and GABA in both AB and TU zebrafish. AB zebrafish showed a significant elevation of taurine levels, but only in the highest alcohol dose group compared to control. These results, albeit mainly negative, together with prior findings suggest that behavioral abnormalities resulting from embryonic alcohol exposure described before for AB zebrafish may primarily be due to altered dopaminergic and serotoninergic mechanisms. Furthermore, a Principal Component Analysis conducted with all neurochemicals tested in this and in our prior study, found a strain-dependent correlation structure response to embryonic alcohol treatment, confirming that embryonic alcohol effects may be genotype dependent.
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Affiliation(s)
- Samantha Mahabir
- Department of Cell & Systems Biology, University of Toronto, Canada
| | | | - Robert Gerlai
- Department of Cell & Systems Biology, University of Toronto, Canada; Department of Psychology, University of Toronto Mississauga, Canada.
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3
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Capillary electrophoresis hyphenated with UV-native-laser induced fluorescence detection (CE/UV-native-LIF). Electrophoresis 2016; 38:135-149. [DOI: 10.1002/elps.201600248] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 07/11/2016] [Accepted: 07/12/2016] [Indexed: 01/01/2023]
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4
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Crick EW, Osorio I, Frei M, Mayer AP, Lunte CE. Correlation of 3-mercaptopropionic acid induced seizures and changes in striatal neurotransmitters monitored by microdialysis. Eur J Pharm Sci 2014; 57:25-33. [PMID: 24462767 PMCID: PMC4004672 DOI: 10.1016/j.ejps.2013.11.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 11/11/2013] [Indexed: 10/25/2022]
Abstract
OBJECTIVES The goal of this study was to use a status epilepticus steady-state chemical model in rats using the convulsant, 3-mercaptopropionic acid (3-MPA), and to compare the changes in striatal neurotransmission on a slow (5min) and fast (60s) timescale. In vivo microdialysis was combined with electrophysiological methods in order to provide a complete evaluation of the dynamics of the results obtained. OBJECTIVE To compare the effects of a steady-state chemical model pof status epilepticus on striatal amino-acid and amine neurotransmitters contents, as measured via in vivo microdialysis combined with electrophysiological methods. Measurements were performed on samples collected every 60s and every 5min. "Fast" (60s) and "slow" (5min) sampling timescales were selected, to gain more insight into the dynamics of GABA synthesis inhibition and of its effects on other neurotransmitters and on cortical electrical activity. METHODS 3-MPA was administered in the form of an intra-venous load (60mg/kg) followed by a constant infusion (50mg/kg/min) for min. Microdialysis samples were collected from the striatum at intervals of 5min and 60s and analyzed for biogenic amine and amino acid neurotransmitters. ECoG activity was monitored via screws placed over the cortex. RESULTS In the 5min samples, glutamate (Glu) increased and γ-aminobutyric acid (GABA) decreased monotonically while changes in dopamine (DA) concentration were bimodal. In the sixty second samples, Glu changes were bimodal, a feature that was not apparent with the 5min samples. ECoG activity was indicative of status epilepticus. CONCLUSIONS This study describes the combination of in vivo microdialysis with electrophysiology to monitor the effect of 3-MPA on neurotransmission in the brain. This led to a better understanding of the chemical changes in the striatum due to the applied 3-MPA chemical model of status epilepticus.
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Affiliation(s)
- Eric W Crick
- R.N. Adams Institute for Bioanalytical Chemistry, Department of Chemistry, University of Kansas, 2030 Becker Drive, Lawrence, KS 66047, United States
| | - Ivan Osorio
- Comprehensive Epilepsy Center, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160, United States; Flint Hills Scientific, LLC, 5040 Bob Billings Parkway, Suite A, Lawrence, KS 66049, United States
| | - Mark Frei
- Flint Hills Scientific, LLC, 5040 Bob Billings Parkway, Suite A, Lawrence, KS 66049, United States
| | - Andrew P Mayer
- R.N. Adams Institute for Bioanalytical Chemistry, Department of Chemistry, University of Kansas, 2030 Becker Drive, Lawrence, KS 66047, United States
| | - Craig E Lunte
- R.N. Adams Institute for Bioanalytical Chemistry, Department of Chemistry, University of Kansas, 2030 Becker Drive, Lawrence, KS 66047, United States.
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5
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Automated method for analysis of tryptophan and tyrosine metabolites using capillary electrophoresis with native fluorescence detection. Anal Bioanal Chem 2013; 405:2451-9. [PMID: 23307134 DOI: 10.1007/s00216-012-6685-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 11/28/2012] [Accepted: 12/20/2012] [Indexed: 02/04/2023]
Abstract
Capillary electrophoresis (CE) with laser-induced native fluorescence (LINF) detection offers the ability to characterize low levels of selected analyte classes, depending on the excitation and emission wavelengths used. Here a new automated CE-LINF system that provides deep ultraviolet (DUV) excitation (224 nm) and variable emission wavelength detection was evaluated for the analysis of small molecule tryptophan- and tyrosine-related metabolites. The optimized instrument design includes several features that increase throughput, lower instrument cost and maintenance, and decrease complexity when compared with earlier systems using DUV excitation. Sensitivity is enhanced by using an ellipsoid detection cell to increase the fluorescence collection efficiency. The limits of detection ranged from 4 to 30 nmol/L for serotonin and tyrosine, respectively. The system demonstrated excellent linearity over several orders of magnitude of concentration and intraday precision from 1-11 % relative standard deviation (RSD). The instrument's performance was validated via tryptophan and serotonin characterization using tissue extracts from the mammalian brain stem, with RSDs of less than 10 % for both metabolites. The flexibility and sensitivity offered by DUV laser excitation and tunable emission enables a broad range of small-volume measurements.
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6
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Squires LN, Rubakhin SS, Wadhams AA, Talbot KN, Nakano H, Moroz LL, Sweedler JV. Serotonin and its metabolism in basal deuterostomes: insights from Strongylocentrotus purpuratus and Xenoturbella bocki. ACTA ACUST UNITED AC 2010; 213:2647-54. [PMID: 20639426 DOI: 10.1242/jeb.042374] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Serotonin (5-HT), an important molecule in metazoans, is involved in a range of biological processes including neurotransmission and neuromodulation. Both its creation and release are tightly regulated, as is its removal. Multiple neurochemical pathways are responsible for the catabolism of 5-HT and are phyla specific; therefore, by elucidating these catabolic pathways we glean greater understanding of the relationships and origins of various transmitter systems. Here, 5-HT catabolic pathways were studied in Strongylocentrotus purpuratus and Xenoturbella bocki, two organisms occupying distinct positions in deuterostomes. The 5-HT-related compounds detected in these organisms were compared with those reported in other phyla. In S. purpuratus, 5-HT-related metabolites include N-acetyl serotonin, gamma-glutamyl-serotonin and 5-hydroxyindole acetic acid; the quantity and type were found to vary based on the specific tissues analyzed. In addition to these compounds, varying levels of tryptamine were also seen. Upon addition of a 5-HT precursor and a monoamine oxidase inhibitor, 5-HT itself was detected. In similar experiments using X. bocki tissues, the 5-HT-related compounds found included 5-HT sulfate, gamma-glutamyl-serotonin and 5-hydroxyindole acetic acid, as well as 5-HT and tryptamine. The sea urchin metabolizes 5-HT in a manner similar to both gastropod mollusks, as evidenced by the detection of gamma-glutamyl-serotonin, and vertebrates, as indicated by the presence of 5-hydroxyindole acetic acid and N-acetyl serotonin. In contrast, 5-HT metabolism in X. bocki appears more similar to common protostome 5-HT catabolic pathways.
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Affiliation(s)
- Leah N Squires
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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7
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CE coupled with amperometric detection using a boron-doped diamond microelectrode: Validation of a method for endogenous norepinephrine analysis in tissue. Electrophoresis 2008; 29:441-7. [DOI: 10.1002/elps.200700398] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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8
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Hatcher NG, Zhang X, Stuart JN, Moroz LL, Sweedler JV, Gillette R. 5-HT and 5-HT-SO4, but not tryptophan or 5-HIAA levels in single feeding neurons track animal hunger state. J Neurochem 2007; 104:1358-63. [PMID: 18036151 DOI: 10.1111/j.1471-4159.2007.05084.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Serotonin (5-HT) is an intrinsic modulator of neural network excitation states in gastropod molluscs. 5-HT and related indole metabolites were measured in single, well-characterized serotonergic neurons of the feeding motor network of the predatory sea-slug Pleurobranchaea californica. Indole amounts were compared between paired hungry and satiated animals. Levels of 5-HT and its metabolite 5-HT-SO4 in the metacerebral giant neurons were observed in amounts approximately four-fold and two-fold, respectively, below unfed partners 24 h after a satiating meal. Intracellular levels of 5-hydroxyindole acetic acid and of free tryptophan did not differ significantly with hunger state. These data demonstrate that neurotransmitter levels and their metabolites can vary in goal-directed neural networks in a manner that follows internal state.
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Affiliation(s)
- N G Hatcher
- Department of Molecular & Integrative Physiology, Department of Chemistry and Beckman Institute, University of Illinois, Urbana, Illinois, USA
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9
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Novotny M, Quaiserova-Mocko V, Wehrwein EA, Kreulen DL, Swain GM. Determination of endogenous norepinephrine levels in different chambers of the rat heart by capillary electrophoresis coupled with amperometric detection. J Neurosci Methods 2007; 163:52-9. [PMID: 17383009 PMCID: PMC2679869 DOI: 10.1016/j.jneumeth.2007.02.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2006] [Revised: 02/12/2007] [Accepted: 02/12/2007] [Indexed: 12/27/2022]
Abstract
Capillary electrophoresis with end-column amperometric detection (CE-EC) was used to determine the regional distribution of norepinephrine (NE) in the hearts of sympathetically innervated (control) and chemically sympathectomized rats. Key features of the method are (i) the sample preparation and clean-up step that involved the application of off-line solid phase extraction (SPE) with a 95% NE recovery and (ii) the use of a diamond microelectrode for detection. NE was quantified in the left and right ventricle, the ventricular septum, and the left and right atrium. The NE concentration in the atria was three to five times higher than in the ventricles and ventricular septum of control rats. Basal NE levels in the left and right ventricle and the ventricular septum were reduced to below the detection limit (0.034 microg/g tissue) in tissues treated with the neurotoxin, 6-hydroxydopamine (6-OHDA), while only a moderate reduction was observed in the left and right atrium. Importantly, the diamond microelectrode provided low and stable background current and low peak-to-peak noise <or=0.65 pA at a detection potential of +0.86 V versus Ag/AgCl. A reproducible electrode response was observed for multiple injections of tissue homogenates with minimal response attenuation due to electrode fouling.
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Affiliation(s)
- Martin Novotny
- Department of Chemistry and the Neuroscience Program, Michigan State University, East Lansing, MI, 48824
| | - Veronika Quaiserova-Mocko
- Department of Chemistry and the Neuroscience Program, Michigan State University, East Lansing, MI, 48824
| | - Erica A. Wehrwein
- Department of Physiology and the Neuroscience Program, Michigan State University, East Lansing, MI, 48824
| | - David L. Kreulen
- Department of Physiology and the Neuroscience Program, Michigan State University, East Lansing, MI, 48824
- Corresponding authors: Greg M. Swain, Department of Chemistry, Michigan State University, 320 Chemistry Building, East Lansing, MI 48824-1322. Tel. (517) 355-9715 x229, Fax. (517)353-1793, Email. . David L. Kreulen, Department of Physiology, Michigan State University, 2201 Biomedical Physical Sciences Building, East Lansing, MI 48824-1320. Tel. (517) 355-6475 x1312, Fax. (517) 355-5125, Email.
| | - Greg M. Swain
- Department of Chemistry and the Neuroscience Program, Michigan State University, East Lansing, MI, 48824
- Corresponding authors: Greg M. Swain, Department of Chemistry, Michigan State University, 320 Chemistry Building, East Lansing, MI 48824-1322. Tel. (517) 355-9715 x229, Fax. (517)353-1793, Email. . David L. Kreulen, Department of Physiology, Michigan State University, 2201 Biomedical Physical Sciences Building, East Lansing, MI 48824-1320. Tel. (517) 355-6475 x1312, Fax. (517) 355-5125, Email.
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Thiébaut D, Vial J, Michel M, Hennion MC, Greibrokk T. Evaluation of reversed phase columns designed for polar compounds and porous graphitic carbon in “trapping” and separating neurotransmitters. J Chromatogr A 2006; 1122:97-104. [PMID: 16723131 DOI: 10.1016/j.chroma.2006.04.074] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2005] [Revised: 04/06/2006] [Accepted: 04/18/2006] [Indexed: 10/24/2022]
Abstract
Quantification of neurotransmitters as biologically active analytes in neurological samples is of high interest for studying their effect on multiple targets. This work is part of a strategy involving two-dimensional liquid chromatography (2D LC) system with mass spectrometry (MS) detection. The concept of the on-line LC system is the coupling of reversed phase liquid chromatography (RPLC, the second separation dimension) to ion-exchange chromatography (IEC, the first dimension). Our objective in this study is to find the appropriate second dimension column, ensuring that samples of neurotransmitters are refocused and separated on it. Silica-based columns designed specifically to retain polar compounds were tested in LC conditions and compared with results obtained with a porous graphitic carbon (PGC, Hypercarb) column. These polar embedded, polar endcapped, and high-density alkyl chain columns successfully separated analytes in question using mobile phase systems with high percentage of water, or even pure water. Only Hypercarb column provided efficient retention of the most polar neurotransmitters and could be used for trapping and preconcentrating the compounds without rapid breakthrough.
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Affiliation(s)
- Didier Thiébaut
- Laboratoire Environnement et Chimie Analytique (CNRS, UMR 7121), ESPCI, 10 rue Vauquelin, 75005 Paris, France.
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11
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Squires LN, Jakubowski JA, Stuart JN, Rubakhin SS, Hatcher NG, Kim WS, Chen K, Shih JC, Seif I, Sweedler JV. Serotonin Catabolism and the Formation and Fate of 5-Hydroxyindole Thiazolidine Carboxylic Acid. J Biol Chem 2006; 281:13463-13470. [PMID: 16537538 DOI: 10.1074/jbc.m602210200] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Serotonin (5-HT) functions as a neurotransmitter and neuromodulator in both the central and enteric nervous systems of mammals. The dynamic degradation of 5-HT metabolites in 5-HT-containing nervous system tissues is monitored by capillary electrophoresis with wavelength-resolved laser-induced native fluorescence detection in an effort to investigate known and novel 5-HT catabolic pathways. Tissue samples from wild type mice, genetically altered mice, Long Evans rats, and cultured differentiated rat pheochromocytoma PC-12 cells, are analyzed before and after incubation with excess 5-HT. From these experiments, several new compounds are detected. One metabolite, identified as 5-hydroxyindole thiazoladine carboxylic acid (5-HITCA), has been selected for further study. In 5-HT-incubated central and enteric nervous system tissue samples and differentiated PC-12 cells, 5-HITCA forms at levels equivalent to 5-hydroxyindole acetic acid, via a condensation reaction between L-cysteine and 5-hydroxyindole acetaldehyde. In the enteric nervous system, 5-HITCA is detected without the addition of 5-HT. The levels of L-cysteine and homocysteine in rat brain mitochondria are measured between 80 and 140 microm and 1.9 and 3.4 microm, respectively, demonstrating that 5-HITCA can be formed using available, free L-cysteine in these tissues. The lack of significant accumulation of 5-HITCA in the central and enteric nervous systems, along with data showing the degradation of 5-HITCA into 5-hydroxyindole acetaldehyde, suggests that an equilibrium coupled to the enzyme, aldehyde dehydrogenase type 2, prevents the accumulation of 5-HITCA. Even so, the formation of 5-HITCA represents a catabolic pathway of 5-HT that can affect the levels of 5-HT-derived compounds in the body.
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Affiliation(s)
- Leah N Squires
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Jennifer A Jakubowski
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Jeffrey N Stuart
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Stanislav S Rubakhin
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Nathan G Hatcher
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Won-Suk Kim
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Kevin Chen
- Department of Molecular Pharmacology and Toxicology, Pharmaceutical Sciences Center, Keck School of Medicine, University of Southern California, Los Angeles, California 90089
| | - Jean C Shih
- Department of Molecular Pharmacology and Toxicology, Pharmaceutical Sciences Center, Keck School of Medicine, University of Southern California, Los Angeles, California 90089
| | - Isabelle Seif
- CNRS, Unité Mixte de Recherche 146, Institut Curie, 91405 Orsay, France
| | - Jonathan V Sweedler
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801.
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12
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Cao L, Wang H, Zhang H. Analytical potential of 6-oxy-(N-succinimidyl acetate)-9-(2'-methoxycarbonyl) fluorescein for the determination of amino compounds by capillary electrophoresis with laser-induced fluorescence detection. Electrophoresis 2005; 26:1954-62. [PMID: 15818574 DOI: 10.1002/elps.200410227] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The analytical potential of a fluorescein analogue, 6-oxy-(N-succinimidyl acetate)-9-(2'-methoxycarbonyl) fluorescein (SAMF), for the first time synthesized in our laboratory, as a labeling reagent for the labeling and determination of amino compounds by capillary electrophoresis (CE) with laser-induced fluorescence (LIF) detection was investigated. Biogenic monoamines and amino acids were chosen as model analytes to evaluate the analytical possibilities of this approach. The derivatization conditions and separation parameters for the biogenic amines were optimized in detail. The derivatization was performed at 30 degrees C for 6 min in boric acid buffer (pH 8.0). The derivatives were baseline-separated in 15 min with 25 mM boric acid running buffer (pH 9.0), containing 24 mM SDS and 12.5% v/v acetonitrile. The concentration detection limit for biogenic amines reaches 8 x 10(-11) mol.L(-1) (signal-to-noise ratio = 3). The application of CE in the analysis of the SAMF-derivatized amino acids was also exploited. The optimal running buffer for amino acids suggested that weak acidic background electrolyte offered better separation than the basic one. The proposed method was applied to the determination of biogenic amines in three different beer samples with satisfying recoveries varying from 92.8% to 104.8%. Finally, comparison of several fluorescein-based probes for amino compounds was discussed. With good labeling reaction, excellent photostability, pH-independent fluorescence (pH 4-9), and the resultant widely suited running buffer pH, SAMF has a great prospect in the determination of amino compounds in CE.
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Affiliation(s)
- Liwei Cao
- Department of Chemistry, Wuhan University, Wuhan 430072, China
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13
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Klampfl CW. Determination of Underivatized Amino Acids by Capillary Electrophoresis and Capillary Electrochromatography. JOURNAL OF CHROMATOGRAPHY LIBRARY 2005. [DOI: 10.1016/s0301-4770(05)80012-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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14
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Stuart JN, Zhang X, Jakubowski JA, Romanova EV, Sweedler JV. Serotonin catabolism depends upon location of release: characterization of sulfated and gamma-glutamylated serotonin metabolites in Aplysia californica. J Neurochem 2003; 84:1358-66. [PMID: 12614336 DOI: 10.1046/j.1471-4159.2003.01617.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Serotonin is a vital neurotransmitter for the functioning of the nervous system in species throughout the animal phyla. Despite its ubiquitous nature, the metabolism of this molecule has yet to be completely elucidated in even the most basic of organisms. Two novel serotonin catabolites, serotonin-O-sulfate and gamma-glu-serotonin-O-sulfate, are chemically characterized using capillary electrophoresis with wavelength-resolved fluorescence detection and electrospray mass spectrometry, and the formation of gamma-glu-serotonin in Aplysia californica is confirmed. These novel compounds appear to be synthesized enzymatically, and known mammalian enzymes exist for all serotonin transformations observed here. The pathway of serotonin inactivation depends upon the type of neuronal tissue subjected to neurotransmitter incubation, with assorted serotonin products observed in distinct locations. Initially demonstrated to be in the metacerebral cell (MCC) soma, the new serotonin metabolite serotonin-O-sulfate may contribute to important functions in the serotonergic system beyond simple serotonin inactivation.
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Affiliation(s)
- Jeffrey N Stuart
- Department of Chemistry, University of Illinois, Urbana, Illinois 61801, USA
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15
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Zhang X, Kim WS, Hatcher N, Potgieter K, Moroz LL, Gillette R, Sweedler JV. Interfering with nitric oxide measurements. 4,5-diaminofluorescein reacts with dehydroascorbic acid and ascorbic acid. J Biol Chem 2002; 277:48472-8. [PMID: 12370177 DOI: 10.1074/jbc.m209130200] [Citation(s) in RCA: 157] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
4,5-Diaminofluorescein (DAF-2) is widely used for detection and imaging of NO based on its sensitivity, noncytotoxicity, and specificity. In the presence of oxygen, NO and NO-related reactive nitrogen species nitrosate 4,5-diaminofluorescein to yield the highly fluorescent DAF-2 triazole (DAF-2T). However, as reported here, the DAF-2 reaction to form a fluorescent product is not specific to NO because it reacts with dehydroascorbic acid (DHA) and ascorbic acid (AA) to generate new compounds that have fluorescence emission profiles similar to that of DAF-2T. When DHA is present, the formation of DAF-2T is attenuated because the DHA competes for DAF-2, whereas AA decreases the nitrosation of DAF-2 to a larger extent, possibly because of additional reducing activity that affects the amount of available N(2)O(3) from the NO. The reaction products of DAF-2 with DHA and AA have been characterized using capillary electrophoresis with laser-induced fluorescence detection and electrospray mass spectrometry. The reactions of DAF-2 with DHA and AA are particularly significant because DHA and AA often colocalize with nitric-oxide synthase in the central nervous, cardiovascular, and immune systems, indicating the importance of understanding this chemistry.
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Affiliation(s)
- Xin Zhang
- Department of Chemistry and the Beckman Institute, University of Illinois, Urbana 61801, USA
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