| 1. |
- Fridjonsdottir, Elva, et al.
(författare)
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Mass spectrometry imaging reveals brain-region specific changes in metabolism and acetylcholine levels in experimental Parkinson’s disease and L-DOPA-induced dyskinesia
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- There is evidence that cholinergic alterations are linked to various motor and non-motor symptoms of Parkinson’s disease. We therefore used mass spectrometry imaging to investigate regional changes in acetylcholine abundance in the brain of a non-human primate model of Parkinson’s disease (PD) and L-DOPA-induced dyskinesia (LID). We also present an experimental design for performing untargeted analysis using MALDI-MSI with multiple experiments incorporating quality control samples to monitor experimental variability. We observed that MPTP treatment (i) led to reductions in putaminal acetylcholine levels that persisted after L-DOPA treatment and (ii) appeared to induce a shift of choline metabolism from α-glycerophosphocholine towards betaine. LID animals exhibited reduced levels of various metabolites important for brain homeostasis including S-adenosylmethionine, glutathione, adenosine monophosphate, and acylcarnitines. The vasculature marker heme B was upregulated in the putamen of LID animals, suggesting increased blood-flow in the dyskinetic putamen. These results provide new insights into pathological choline-related metabolic changes in PD and LID.
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| 2. |
- Vallianatou, Theodosia, et al.
(författare)
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Rapid Metabolic Profiling of 1 ÎŒL Crude Cerebrospinal Fluid by Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging Can Differentiate De Novo Parkinson's Disease
- 2023
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Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 95:50, s. 18352-18360
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Tidskriftsartikel (refereegranskat)abstract
- Parkinson's disease (PD) is a highly prevalent neurodegenerative disorder affecting the motor system. However, the correct diagnosis of PD and atypical parkinsonism may be difficult with high clinical uncertainty. There is an urgent need to identify reliable biomarkers using high-throughput, molecular-specific methods to improve current diagnostics. Here, we present a matrix-assisted laser desorption/ionization mass spectrometry imaging method that requires minimal sample preparation and only 1 mu L of crude cerebrospinal fluid (CSF). The method enables analysis of hundreds of samples in a single experiment while simultaneously detecting numerous metabolites with subppm mass accuracy. To test the method, we analyzed CSF samples from 12 de novo PD patients (that is, newly diagnosed and previously untreated) and 12 age-matched controls. Within the identified molecules, we found neurotransmitters and their metabolites such as gamma-aminobutyric acid, 3-methoxytyramine, homovanillic acid, serotonin, histamine, amino acids, and metabolic intermediates. Limits of detection were estimated for multiple neurotransmitters with high linearity (R-2 > 0.99) and sensitivity (as low as 16 pg/mu L). Application of multivariate classification led to a highly significant (P < 0.001) model of PD prediction with a 100% classification rate, which was further thoroughly validated with a permutation test and univariate analysis. Molecules related to the neuromelanin pathway were found to be significantly increased in the PD group, indicated by their elevated relative intensities compared to the control group. Our method enables rapid detection of PD-related biomarkers in low sample volumes and could serve as a valuable tool in the development of robust PD diagnostics.
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| 3. |
- Vallianatou, Theodosia, et al.
(författare)
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Rapid metabolic profiling of one microliter crude CSF by MALDI MS can differentiate de novo Parkinson’s disease
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Parkinson’s disease (PD) is a highly prevalent neurodegenerative disorder affecting the motor system. However, the correct diagnosis of PD and atypical parkinsonism may be difficult, with high clinical uncertainty. The disease is diagnosed solely based on the presence of clinical symptoms, and there is an urgent need to identify reliable biomarkers using high-throughput, molecular-specific methods to improve current diagnostics. Here, we present a matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) method that requires minimal sample preparation and only one µl of crude cerebrospinal fluid (CSF). The method enables analysis of hundreds of samples in a single experiment while simultaneously detecting numerous metabolites with sub-ppm mass accuracy. To test the method, we analyzed CSF samples from 12 de novo PD patients (that is, newly diagnosed and previously untreated) and 12 age-matched controls. Within the identified molecules, we found neurotransmitters and their metabolites, such as γ-aminobutyric acid, 3-methoxytyramine, homovanillic acid, serotonin, histamine, amino acids, and metabolic intermediates. Limits of detection were estimated for multiple neurotransmitters with high linearity (R2 > 0.99) and sensitivity (as low as 16 pg/µl). Application of multivariate classification led to a highly significant (P <0.001) model of PD prediction with 100% classification rate, which was further thoroughly validated with permutation test and univariate analysis. Molecules related to the neuromelanin pathway were found to be increased in the PD group. Our method enables rapid detection of PD-related biomarkers in low sample volumes and could serve as a valuable tool in the development of robust PD diagnostics.
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| 4. |
- Aerts, Jordan
(författare)
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Capillary electrophoresis mass spectrometry applied to structural proteomics and small molecule analysis
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Capillary electrophoresis with mass spectrometric (CE–MS) detection offers a separation method without equal in terms of flexibility, utility, and cost efficiency. Here we demonstrate precisely this through the application of several laboratory-built CE–MS instruments for the separation of brain metabolites in non-primates, enantioselective separations of synthetic anesthetic metabolites in fractionated pony urine, application in structural proteomics workflows, and identification of exogenous alkaloid biotransformationproducts in human cerebrospinal fluid (CSF).We outline a method for quickly and affordably etching austenitic steel tubing, which is widely used in electrospray sources for CE–MS. The stainless steel tapered tip emitters provide robust electrospray with low sheath liquid flow rates and can be easily fabricated in-house, offering flexibility and cost-efficiency when commercial options areunavailable. We contribute a CE–MS method for enantiomer separation, specifically targeting 6-hydroxynorketamine (HNK). By introducing chiral selectors into the separation capillary, the method enables efficient enantiomer separation and offers a newtool to assist with research on HNK as a cure for depression.We explore the feasibility of cold CE–MS in hydrogen deuterium exchange workflows. The utilization of a lab-designed Peltier-cooled CE device achieves deuterium back exchange rates on par with commercial liquid chromatography-based platforms, offering new possibilities for studying protein structures and interactions.We also demonstrate the wide ranging versatility of CE–MS with contributions to the identification of specific tobacco related metabolites in CSF samples during the development of a high throughput mass spectrometry diagnostic tool for Parkinson’sDisease.This thesis showcases the versatility and value of CE–MS in various applications, a true blessing for analytical chemistry.
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| 5. |
- Aerts, Jordan, et al.
(författare)
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Electrochemically Etched Tapered-Tip Stainless-Steel Electrospray-Ionization Emitters for Capillary Electrophoresis-Mass Spectrometry
- 2023
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 22:4, s. 1377-1380
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Tidskriftsartikel (refereegranskat)abstract
- We have used household consumables to facilitate electrochemical etching of stainless-steel hypodermic tubing to produce tapered-tip emitters suitable for electrospray ionization for use in mass spectrometry. The process involves the use of 1% oxalic acid and a 5 W USB power adapter, commonly known as a phone charger. Further, our method avoids the otherwise commonly used strong acids that entail chemical hazards: concentrated HNO3 for etching stainless steel, or concentrated HF for etching fused silica. Hence, we here provide a convenient and self-inhibiting procedure with minimal chemical hazards to manufacture tapered-tip stainless-steel emitters. We show its performance in metabolomic analysis with CE-MS of a tissue homogenate where the metabolites acetylcarnitine, arginine, carnitine, creatine, homocarnosine, and valerylcarnitine were identified, all with basepeak separated electropherograms, within <6 min of separation. The mass spectrometry data are freely available through the MetaboLight public data repository via access number MTBLS7230.
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| 6. |
- Aerts, Jordan, et al.
(författare)
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Zero-Degree Celsius Capillary Electrophoresis Electrospray Ionization for Hydrogen Exchange Mass Spectrometry
- 2023
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Ingår i: Analytical Chemistry. - : Springer Nature. - 0003-2700 .- 1520-6882. ; 95:2, s. 1149-1158
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Tidskriftsartikel (refereegranskat)abstract
- Currently, fast liquid chromatographic separations at low temperatures are exclusively used for the separation of peptides generated in hydrogen deuterium exchange (HDX) workflows. However, it has been suggested that capillary electrophoresis may be a better option for use with HDX. We performed in solution HDX on peptides and bovine hemoglobin (Hb) followed by quenching, pepsin digestion, and cold capillary electrophoretic separation coupled with mass spectrometry (MS) detection for benchmarking a laboratory-built HDX–MS platform. We found that capillaries with a neutral coating to eliminate electroosmotic flow and adsorptive processes provided fast separations with upper limit peak capacities surpassing 170. In contrast, uncoated capillaries achieved 30% higher deuterium retention for an angiotensin II peptide standard owing to faster separations but with only half the peak capacity of coated capillaries. Data obtained using two different separation conditions on peptic digests of Hb showed strong agreement of the relative deuterium uptake between methods. Processed data for denatured versus native Hb after deuterium labeling for the longest timepoint in this study (50,000 s) also showed agreement with subunit interaction sites determined by crystallographic methods. All proteomic data are available under DOI: 10.6019/PXD034245.
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| 7. |
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| 8. |
- Nezhyva, Mariya, et al.
(författare)
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POMC-specific Modulation of Metabolic and Immune Pathways via Melanocortin-3 Receptor Signaling
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- This proteomic study provides a nuanced understanding of the melanocortin-3 receptor (MC3R) and its ligand-specific effects on metabolic and immune pathways. Utilizing thermal proteome profiling with tandem mass spectrometry, we uncovered the distinct influences of adrenocorticotropic hormone (ACTH), α-melanocyte-stimulating hormone (α-MSH), and γ-melanocyte-stimulating hormone (γ-MSH) on protein thermal stability and pathway activation. ACTH uniquely affected NADPH-related metabolic proteins, α-MSH significantly modulated the IL-6 pathway via STAT3, and γ-MSH prominently activated interferon signaling. All ligands shared involvement in the cAMP-PKA-CREB and varied impacts on PI3K and ERK pathways, crucial for energy metabolism. Additionally, ligand-specific responses in mitochondrial protein stability suggest a role in cellular energy generation.
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| 9. |
- Nezhyva, Mariya, et al.
(författare)
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Spatial multiomic insights into acute cocaine exposure
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Recent studies provide compelling evidence that cocaine-induced neurotoxicity begins within hours of a single acute cocaine exposure. Despite this, a comprehensive understanding of the molecular alterations occurring in vivo within the reward system following such an exposure has been lacking. In this study, we developed an analytical workflow that combines mass spectrometry imaging with microscale proteomics of brain regions. Here, we present a multiomic perspective on the molecular consequences of acute cocaine exposure on the principal areas of the reward system and the hippocampus. Our findings include distinct region-specific alterations in the tricarboxylic acid (TCA) cycle and lipid synthesis within the reward circuitry highlighting a significant energy depletion in mice 24 hours post-cocaine injections. Additionally, we linked widespread reductions in key neurotransmitters (GABA, glutamate, aspartate) across the reward system and calcium level modifications to changes in synaptic plasticity and mitochondria dysfunction. Mitochondrial dysfunction and energy metabolism disruption were evident through imbalances in the mitochondrial ATP production and electron transport chain components, increased susceptibility to oxidative stress, disturbances in mitochondrial transport proteins, and fluctuations in creatine and taurine levels. Among the brain regions within the reward circuitry, the prefrontal cortex (PFC) exhibited the most pronounced effects. This study not only provides a holistic overview of the intricate interplay between proteins and metabolites within the reward circuitry regions during the onset of cocaine-induced neurotoxicity but also offers novel insights into the underlying molecular mechanisms.
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| 10. |
- Rofo, Fadi, et al.
(författare)
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Wide-Ranging Effects on the Brain Proteome in a Transgenic Mouse Model of Alzheimer's Disease Following Treatment with a Brain-Targeting Somatostatin Peptide
- 2021
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Ingår i: ACS Chemical Neuroscience. - : American Chemical Society (ACS). - 1948-7193. ; 12:13, s. 2529-2541
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Tidskriftsartikel (refereegranskat)abstract
- Alzheimer’s disease is the most common neurodegenerative disorder characterized by the pathological aggregation of amyloid-β (Aβ) peptide. A potential therapeutic intervention in Alzheimer’s disease is to enhance Aβ degradation by increasing the activity of Aβ-degrading enzymes, including neprilysin. The somatostatin (SST) peptide has been identified as an activator of neprilysin. Recently, we demonstrated the ability of a brain-penetrating SST peptide (SST-scFv8D3) to increase neprilysin activity and membrane-bound Aβ42 degradation in the hippocampus of mice overexpressing the Aβ-precursor protein with the Swedish mutation (APPswe). Using LC–MS, we further evaluated the anti-Alzheimer’s disease effects of SST-scFv8D3. Following a triple intravenous injection of SST-scFv8D3, the LC–MS analysis of the brain proteome revealed that the majority of downregulated proteins consisted of mitochondrial proteins regulating fatty acid oxidation, which are otherwise upregulated in APPswe mice compared to wild-type mice. Moreover, treatment with SST-scFv8D3 significantly increased hippocampal levels of synaptic proteins regulating cell membrane trafficking and neuronal development. Finally, hippocampal concentrations of growth-regulated α (KC/GRO) chemokine and degradation of neuropeptide-Y were elevated after SST-scFv8D3 treatment. In summary, our results demonstrate a multifaceted effect profile in regulating mitochondrial function and neurogenesis following treatment with SST-scFv8D3, further suggesting the development of Alzheimer’s disease therapies based on SST peptides.
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