| 1. |
- Aguei-Gonzalez, P., et al.
(författare)
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Secondary Ion Mass Spectrometry Imaging Reveals Changes in the Lipid Structure of the Plasma Membranes of Hippocampal Neurons following Drugs Affecting Neuronal Activity
- 2021
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Ingår i: Acs Chemical Neuroscience. - : American Chemical Society (ACS). - 1948-7193. ; 12:9, s. 1542-1551
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Tidskriftsartikel (refereegranskat)abstract
- The cellular functions of lipids in the neuronal plasma membranes have been increasingly acknowledged, particularly their association to neuronal processes and synaptic plasticity. However, the knowledge of their regulatory mechanisms in neuronal cells remains sparse. To address this, we investigated the lipid organization of the plasma membranes of hippocampal neurons in relation to neuronal activity using secondary ion mass spectrometry imaging. The neurons were treated with drugs, particularly tetrodotoxin (TTX) and bicuculline (BIC), to induce chronic activation and silencing. Distinct lipid organization was found in the plasma membrane of the cell body and the neurites. Moreover, significant alterations of the levels of the membrane lipids, especially ceramides, phosphatidylserines, phosphatidic acids, and triacylglycerols, were observed under the TTX and BIC treatments. We suggest that many types of membrane lipids are affected by, and may be involved in, the regulation of neuronal function.
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| 2. |
- Agui-Gonzalez, P., et al.
(författare)
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Gold-Conjugated Nanobodies for Targeted Imaging Using High-Resolution Secondary Ion Mass Spectrometry
- 2021
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Ingår i: Nanomaterials. - : MDPI AG. - 2079-4991. ; 11:7
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Tidskriftsartikel (refereegranskat)abstract
- Nanoscale imaging with the ability to identify cellular organelles and protein complexes has been a highly challenging subject in the secondary ion mass spectrometry (SIMS) of biological samples. This is because only a few isotopic tags can be used successfully to target specific proteins or organelles. To address this, we generated gold nanoprobes, in which gold nanoparticles are conjugated to nanobodies. The nanoprobes were well suited for specific molecular imaging using NanoSIMS at subcellular resolution. They were demonstrated to be highly selective to different proteins of interest and sufficiently sensitive for SIMS detection. The nanoprobes offer the possibility of correlating the investigation of cellular isotopic turnover to the positions of specific proteins and organelles, thereby enabling an understanding of functional and structural relations that are currently obscure.
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| 3. |
- Berglund, E Carina, et al.
(författare)
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Oral administration of methylphenidate blocks the effect of cocaine on uptake at the Drosophila dopamine transporter.
- 2013
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Ingår i: ACS chemical neuroscience. - : American Chemical Society (ACS). - 1948-7193. ; 4:4, s. 566-74
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Tidskriftsartikel (refereegranskat)abstract
- Although our understanding of the actions of cocaine in the brain has improved, an effective drug treatment for cocaine addiction has yet to be found. Methylphenidate binds the dopamine transporter and increases extracellular dopamine levels in mammalian central nervous systems similar to cocaine, but it is thought to elicit fewer addictive and reinforcing effects owing to slower pharmacokinetics for different routes of administration between the drugs. This study utilizes the fruit fly model system to quantify the effects of oral methylphenidate on dopamine uptake during direct cocaine exposure to the fly CNS. The effect of methylphenidate on the dopamine transporter has been explored by measuring the uptake of exogenously applied dopamine. The data suggest that oral consumption of methylphenidate inhibits the Drosophila dopamine transporter and the inhibition is concentration dependent. The peak height increased to 150% of control when cocaine was used to block the dopamine transporter for untreated flies but only to 110% for methylphenidate-treated flies. Thus, the dopamine transporter is mostly inhibited for the methylphenidate-fed flies before the addition of cocaine. The same is true for the rate of the clearance of dopamine measured by amperometry. For untreated flies the rate of clearance changes 40% when the dopamine transporter is inhibited with cocaine, and for treated flies the rate changes only 10%. The results were correlated to the in vivo concentration of methylphenidate determined by CE-MS. Our data suggest that oral consumption of methylphenidate inhibits the Drosophila dopamine transporter for cocaine uptake, and the inhibition is concentration dependent.
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| 4. |
- Berlin, Emmanuel, et al.
(författare)
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Lipid organization and turnover in the plasma membrane of human differentiating neural progenitor cells revealed by time-of-flight secondary ion mass spectrometry imaging
- 2024
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Ingår i: TALANTA. - 0039-9140 .- 1873-3573. ; 272
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Tidskriftsartikel (refereegranskat)abstract
- Membrane lipids have been known to influence multiple signalling and cellular processes. Dysregulation of lipids at the neuronal membrane is connected to a significant alteration of the brain function and morphology, leading to brain diseases and neurodegeneration. Understanding the lipid composition and turnover of neuronal membrane will provide a significant insight into the molecular events underlying the regulatory effects of these biomolecules in a neuronal system. In this study, we aimed to characterize the composition and turnover of the plasma membrane lipids in human neural progenitor cells (NPCs) at an early differentiation stage into midbrain neurons using ToF-SIMS imaging. Lipid composition of the native plasma membrane was explored, followed by an examination of the lipid turnover using different isotopically labelled lipid precursors, including 13C-choline, 13C-lauric acid, 15N-linoleic, and 13C-stearic. Our results showed that differentiating NPCs contain a high abundance of ceramides, glycerophosphoserines, neutral glycosphingolipids, diradylglycerols, and glycerophosphocholines at the plasma membrane. In addition, different precursors were found to incorporate into different membrane lipids which are specific for the short- or long -carbon chains, and the unsaturation or saturation stage of the precursors. The lipid structure of neuronal membrane reflects the differentiation status of NPCs, and it can be altered significantly using a particular lipid precursor. Our study illustrates a potential of ToF-SIMS imaging to study native plasma membrane lipids and elucidate complex cellular processes by providing molecular -rich information at a cell level.
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| 5. |
- Hanrieder, Jörg, 1980, et al.
(författare)
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Imaging mass spectrometry in neuroscience.
- 2013
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Ingår i: ACS chemical neuroscience. - : American Chemical Society (ACS). - 1948-7193. ; 4:5, s. 666-79
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Tidskriftsartikel (refereegranskat)abstract
- Imaging mass spectrometry is an emerging technique of great potential for investigating the chemical architecture in biological matrices. Although the potential for studying neurobiological systems is evident, the relevance of the technique for application in neuroscience is still in its infancy. In the present Review, a principal overview of the different approaches, including matrix assisted laser desorption ionization and secondary ion mass spectrometry, is provided with particular focus on their strengths and limitations for studying different neurochemical species in situ and in vitro. The potential of the various approaches is discussed based on both fundamental and biomedical neuroscience research. This Review aims to serve as a general guide to familiarize the neuroscience community and other biomedical researchers with the technique, highlighting its great potential and suitability for comprehensive and specific chemical imaging.
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| 6. |
- Hoang Philipsen, Thuy Mai, 1988, et al.
(författare)
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Interplay between Cocaine, Drug Removal, and Methylphenidate Reversal on Phospholipid Alterations in Drosophila Brain Determined by Imaging Mass Spectrometry
- 2020
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Ingår i: ACS Chemical Neuroscience. - : American Chemical Society (ACS). - 1948-7193. ; 11:5, s. 806-813
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Tidskriftsartikel (refereegranskat)abstract
- Cocaine dependence displays a broad impairment in cognitive performance including attention, learning, and memory. To obtain a better understanding of the action of cocaine in the nervous system, and the relation between phospholipids and memory, we have investigated whether phospholipids recover in the brain following cocaine removal using the fly model, Drosophila melanogaster. In addition, the effects of methylphenidate, a substitute medication for cocaine dependence, on fly brain lipids after cocaine abuse are also determined to see if it can rescue the lipid changes caused by cocaine. Time of flight secondary ion mass spectrometry with a (CO2)6000+ gas cluster ion beam was used to detect intact phospholipids. We show that cocaine has persistent effects, both increasing and decreasing the levels of specific phosphatidylethanolamines and phosphatidylinositols. These changes remain after cocaine withdrawal and are not rescued by methylphenidate. Cocaine is again shown to generally increase the levels of phosphatidylcholines in the fly brain; however, after drug withdrawal, the abundance of these lipids returns to the original level and methylphenidate treatment of the flies following cocaine exposure enhances the reversal of the lipid level reducing them below the original control. The study provides insight into the molecular effects of cocaine and methylphenidate on brain lipids. We suggest that phosphatidylcholines could be a potential target for the treatment of cocaine abuse as well as be a significant hallmark of cognition and memory loss with cocaine.
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| 7. |
- Hu, Keke, et al.
(författare)
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Electrochemical Measurements Reveal Reactive Oxygen Species in Stress Granules**
- 2021
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Ingår i: Angewandte Chemie - International Edition. - : Wiley. - 1433-7851 .- 1521-3773. ; 60:28, s. 15302-15306
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Tidskriftsartikel (refereegranskat)abstract
- Stress granules (SGs) are membrane-less organelles that assemble in the cytoplasm to organize cellular contents and promote rapid adaptation during stress. To understand how SGs contribute to physiological functions, we used electrochemical measurements to detect electroactive species in SGs. With amperometry, we discovered that reactive oxygen species (ROS) are encapsulated inside arsenite-induced SGs, and H2O2 is the main species. The release kinetics of H2O2 from single SGs and the number of H2O2 molecules were quantified. The discovery that SGs contain ROS implicates them as communicators of the cellular stresses rather than a simple endpoint. This may explain how SGs regulate cellular metabolism and stress responses. This may also help better understand their cytoprotective functions in pathological conditions associated with SGs such as neurodegenerative diseases (NDs), cancers and viral infections. © 2021 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.
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| 8. |
- Hu, K. K., et al.
(författare)
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Single Exosome Amperometric Measurements Reveal Encapsulation of Chemical Messengers for Intercellular Communication
- 2023
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Ingår i: Journal of the American Chemical Society. - 0002-7863. ; 145:21, s. 11499-11503
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Tidskriftsartikel (refereegranskat)abstract
- In multicellular organisms, cellstypically communicateby sendingand receiving chemical signals. Chemical messengers involved in theexocytosis of neuroendocrine cells or neurons are generally assumedto only originate from the fusing of intracellular large dense corevesicles (LDCVs) or synaptic vesicles with the cellular membrane followingstimulation. Accumulated evidence suggests that exosomes oneof the main extracellular vesicles (EVs)carrying cell-dependentDNA, mRNA, proteins, etc., play an essential role in cellular communication.Due to experimental limitations, it has been difficult to monitorthe real-time release of individual exosomes; this restricts a comprehensiveunderstanding of the basic molecular mechanisms and the functionsof exosomes. In this work, we introduce amperometry with microelectrodesto capture the dynamic release of single exosomes from a single livingcell, distinguish them from other EVs, and differentiate the moleculesinside exosomes and those secreted from LDCVs. We show that, similarto many LDCVs and synaptic vesicles, exosomes released by neuroendocrinecells also contain catecholamine transmitters. This finding revealsa different mode of chemical communication via exosome-encapsulatedchemical messengers and a potential interconnection between the tworelease pathways, changing the canonical view of exocytosis of neuroendocrinecells and possibly neurons. This defines a new mechanism for chemicalcommunication at the fundamental level and opens new avenues in theresearch of the molecular biology of exosomes in the neuroendocrineand central nervous systems.
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| 9. |
- Lanekoff, Ingela, 1975, et al.
(författare)
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Mass spectrometry imaging of freeze-dried membrane phospholipids of dividing Tetrahymena pyriformis
- 2013
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Ingår i: Surface and Interface Analysis. - : Wiley. - 0142-2421 .- 1096-9918. ; 45:1, s. 211-214
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Tidskriftsartikel (refereegranskat)abstract
- Time of Flight secondary ion mass spectrometry (TOF-SIMS) has been used to explore the distribution of phospholipids in the plasma membrane of Tetrahymena pyriformis during cell division. The dividing cells were freeze-dried prior to analysis followed by line scan and region of interest analysis at various stages of cell division. The results showed no signs of phospholipid domain formation at the junction between the dividing cells. Instead the results showed that the sample preparation technique had a great impact on one of the examined phospholipids, namely phosphatidylcholine (PC). Phosphatidylcholine and 2-aminoethylphosphonolipid (2-AEP) have therefore been evaluated in Tetrahymena cells that have been subjected to different sample preparation techniques: freeze drying ex situ, freeze fracture, and freeze fracture with partial or total freeze drying in situ. The result suggests that freeze drying ex situ causes the celia to collapse and cover the plasma membrane.
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| 10. |
- Lange, Felix, et al.
(författare)
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Correlative fluorescence microscopy, transmission electron microscopy and secondary ion mass spectrometry (CLEM-SIMS) for cellular imaging
- 2021
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Ingår i: PLoS ONE. - 1932-6203. ; 16
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Tidskriftsartikel (refereegranskat)abstract
- Electron microscopy (EM) has been employed for decades to analyze cell structure. To also analyze the positions and functions of specific proteins, one typically relies on immuno-EM or on a correlation with fluorescence microscopy, in the form of correlated light and electron microscopy (CLEM). Nevertheless, neither of these procedures is able to also address the isotopic composition of cells. To solve this, a correlation with secondary ion mass spectrometry (SIMS) would be necessary. SIMS has been correlated in the past to EM or to fluorescence microscopy in biological samples, but not to CLEM. We achieved this here, using a protocol based on transmission EM, conventional epifluorescence microscopy and nanoSIMS. The protocol is easily applied, and enables the use of all three technologies at high performance parameters. We suggest that CLEM-SIMS will provide substantial information that is currently beyond the scope of conventional correlative approaches.
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