| 1. |
- Källback, Patrik
(författare)
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Development and Application of Software Tools for Mass Spectrometry Imaging
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Mass spectrometry imaging (MSI) has been extensively used to produce qualitative maps of distributions of proteins, peptides, lipids, neurotransmitters, small molecule pharmaceuticals and their metabolites directly in biological tissue sections. Moreover, during the last 10 years, there has been growing demand to quantify target compounds in tissue sections of various organs. This thesis focuses on development and application of a novel instrument- and manufacturer-independent MSI software suite, msIQuant, in the open access format imzML, which has been developed specifically for quantitative analysis of MSI data. The functionality of msIQuant facilitates automatic generation of calibration curves from series of standards that can be used to determine concentrations of specific analytes. In addition, it provides many tools for image visualization, including modules enabling multiple interpolation, low intensity transparency display, and image fusion and sharpening. Moreover, algorithms and advanced data management modules in msIQuant facilitate management of the large datasets generated following rapid recent increases in the mass and spatial resolutions of MSI instruments, by using spectra transposition and data entropy reduction (at four selectable levels: coarse, medium, fine or superfine) before lossless compression of the data. As described in the thesis, implementation of msIQuant has been exemplified in both quantitative (relative or absolute) and qualitative analyses of distributions of neurotransmitters, endogenous substances and pharmaceutical drugs in brain tissue sections. Our laboratory have developed a molecular-specific approach for the simultaneous imaging and quantitation of multiple neurotransmitters, precursors, and metabolites, such as tyrosine, tryptamine, tyramine, phenethylamine, dopamine, 3-methoxytyramine, serotonin, gamma-aminobutyric acid (GABA), and acetylcholine, in histological tissue sections at high spatial resolution by matrix-assisted laser desorption ionization (MALDI) and desorption electrospray ionization (DESI) MSI. Chemical derivatization by charge-tagging primary amines of analytes significantly increased the sensitivity, enabling mapping of neurotransmitters that were not previously detectable by MSI. The two MSI approaches have been used to directly measure changes in neurotransmitter levels in specific brain structures in animal disease models, which facilitates understanding of biochemical mechanisms of drug treatments. In summary, msIQuant software has proven potency (particularly in combination with the reported derivatization technique) for both qualitative and quantitative analyses. Further developments will enable its implementation in multiple operating system platforms and use for statistical analysis.
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| 2. |
- Martinez-Martin, Pablo, et al.
(författare)
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EuroInf: A Multicenter Comparative Observational Study of Apomorphine and Levodopa Infusion in Parkinson's Disease
- 2015
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Ingår i: Movement Disorders. - : Wiley. - 0885-3185. ; 30:4, s. 510-516
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Tidskriftsartikel (refereegranskat)abstract
- Subcutaneous apomorphine infusion (Apo) and intrajejunal levodopa infusion (IJLI) are two treatment options for patients with advanced Parkinson's disease (PD) and refractory motor complications, with varying cost of treatment. There are no multicenter studies comparing the effects of the two strategies. This open-label, prospective, observational, 6-month, multicenter study compared 43 patients on Apo (48.8% males, age 62.3 +/- 10.6 years; disease duration: 14 +/- 4.4 years; median H & Y stage 3; interquartile range [IQR]: 3-4) and 44 on IJLI (56.8% males, age 62.7 +/- 9.1 years; disease duration: 16.1 +/- 6.7 years; median H & Y stage 4; IQR, 3-4). Cohen's effect sizes (0.8 considered as large) were large with both therapies with respect to total motor, nonmotor, and quality-of-life scores. The Non-Motor Symptoms Scale (NMSS) with Apo showed moderate improvement, whereas sleep/fatigue, gastrointestinal, urinary, and sexual dimensions of the NMSS showed significantly higher improvement with IJLI. Seventy-five percent on IJLI improved in their quality-of-life and nonmotor symptoms (NMS), whereas in the Apo group, a similar proportion improved in quality of life, but 40% in NMS. Adverse effects included peritonitis with IJLI and skin nodules on Apo. Based on this open-label, nonrandomized, comparative study, we report that, in advanced Parkinson's patients, both IJLI and Apo infusion therapy appear to provide a robust improvement in motor symptoms, motor complications, quality-of-life, and some NMS. Controlled, randomized studies are required. (c) 2014 International Parkinson and Movement Disorder Society
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| 3. |
- Paslawski, Wojciech, et al.
(författare)
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alpha-synuclein-lipoprotein interactions and elevated ApoE level in cerebrospinal fluid from Parkinson's disease patients
- 2019
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : NATL ACAD SCIENCES. - 0027-8424 .- 1091-6490. ; 116:30, s. 15226-15235
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Tidskriftsartikel (refereegranskat)abstract
- The progressive accumulation, aggregation, and spread of alpha-synuclein (alpha SN) are common hallmarks of Parkinson's disease (PD) pathology. Moreover, numerous proteins interact with alpha SN species, influencing its toxicity in the brain. In the present study, we extended analyses of alpha SN-interacting proteins to cerebrospinal fluid (CSF). Using coimmunoprecipitation, followed by mass spectrometry, we found that alpha SN colocalize with apolipoproteins on lipoprotein vesicles. We confirmed these interactions using several methods, including the enrichment of lipoproteins with a recombinant alpha SN, and the subsequent uptake of prepared vesicles by human dopaminergic neuronal-like cells. Further, we report an increased level of ApoE in CSF from early PD patients compared with matched controls in 3 independent cohorts. Moreover, in contrast to controls, we observed the presence of ApoE-positive neuromelanin-containing dopaminergic neurons in substantia nigra of PD patients. In conclusion, the cooccurrence of alpha SN on lipoprotein vesicles, and their uptake by dopaminergic neurons along with an increase of ApoE in early PD, proposes a mechanism(s) for alpha SN spreading in the extracellular milieu of PD.
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| 4. |
- Paul-Visse, Gesine, et al.
(författare)
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Safety and tolerability of intracerebroventricular PDGF-BB in Parkinson's disease patients
- 2015
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Ingår i: Journal of Clinical Investigation. - 0021-9738 .- 1558-8238. ; 125:3, s. 1339-1346
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND. Recombinant human PDGF-BB (rhPDGF-BB) reduces Parkinsonian symptoms and increases dopamine transporter (DAT) binding in several animal models of Parkinson's disease (PD). Effects of rhPDGF-BB are the result of proliferation of ventricular wall progenitor cells and reversed by blocking mitosis. Based on these restorative effects, we assessed the safety and tolerability of intracerebroventricular (i.c.v.) rhPDGF-BB administration in individuals with PD. METHODS. We conducted a double-blind, randomized, placebo-controlled phase I/IIa study at two clinical centers in Sweden. Twelve patients with moderate PD received rhPDGF-BB via an implanted drug infusion pump and an investigational i.c.v. catheter. Patients were assigned to a dose cohort (0.2, 1.5, or 5 mu g rhPDGF-BB per day) and then randomized to active treatment or placebo (3:1) for a 12-day treatment period. The primary objective was to assess safety and tolerability of i.c.v.-delivered rhPDGF-BB. Secondary outcome assessments included several clinical rating scales and changes in DAT binding. The follow-up period was 85 days. RESULTS. All patients completed the study. There were no unresolved adverse events. Serious adverse events occurred in three patients; however, these were unrelated to rhPDGF-BB administration. Secondary outcome parameters did not show dose-dependent changes in clinical rating scales, but there was a positive effect on DAT binding in the right putamen. CONCLUSION. At all doses tested, i.c.v. administration of rhPDGF-BB was well tolerated. Results support further clinical development of rhPDGF-BB for patients with PD.
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| 5. |
- Shariatgorji, Mohammadreza, et al.
(författare)
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Comprehensive mapping of neurotransmitter networks by MALDI-MS imaging
- 2019
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Ingår i: Nature Methods. - : NATURE PUBLISHING GROUP. - 1548-7091 .- 1548-7105. ; 16:10, s. 1021-1028
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Tidskriftsartikel (refereegranskat)abstract
- We present a mass spectrometry imaging (MSI) approach for the comprehensive mapping of neurotransmitter networks in specific brain regions. Our fluoromethylpyridinium-based reactive matrices facilitate the covalent charge-tagging of molecules containing phenolic hydroxyl and/or primary or secondary amine groups, including dopaminergic and serotonergic neurotransmitters and their associated metabolites. These matrices improved the matrix-assisted laser desorption/ionization (MALDI)-MSI detection limit toward low-abundance neurotransmitters and facilitated the simultaneous imaging of neurotransmitters in fine structures of the brain at a lateral resolution of 10 mu m. We demonstrate strategies for the identification of unknown molecular species using the innate chemoselectivity of the reactive matrices and the unique isotopic pattern of a brominated reactive matrix. We illustrate the capabilities of the developed method on Parkinsonian brain samples from human post-mortem tissue and animal models. The direct imaging of neurotransmitter systems provides a method for exploring how various neurological diseases affect specific brain regions through neurotransmitter modulation.
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| 6. |
- Shariatgorji, Mohammadreza, et al.
(författare)
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Pyrylium Salts as Reactive Matrices for MALDI-MS Imaging of Biologically Active Primary Amines
- 2015
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Ingår i: Journal of the American Society for Mass Spectrometry. - : American Chemical Society (ACS). - 1044-0305 .- 1879-1123. ; 26:6, s. 934-939
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Tidskriftsartikel (refereegranskat)abstract
- Many neuroactive substances, including endogenous biomolecules, environmental compounds, and pharmaceuticals possess primary amine functional groups. Among these are catecholamine neurotransmitters (e.g., dopamine), many substituted phenethylamines (e.g., amphetamine), as well as amino acids and neuropeptides. In most cases, mass spectrometric (ESI and MALDI) analyses of trace amounts of such compounds are challenging because of their poor ionization properties. We present a method for chemical derivatization of primary amines by reaction with pyrylium salts that facilitates their detection by MALDI-MS and enables the imaging of primary amines in brain tissue sections. A screen of pyrylium salts revealed that the 2,4-diphenyl-pyranylium ion efficiently derivatizes primary amines and can be used as a reactive MALDI-MS matrix that induces both derivatization and desorption. MALDI-MS imaging with such matrix was used to map the localization of dopamine and amphetamine in brain tissue sections and to quantitatively map the distribution of the neurotoxin beta-N-methylamino-L-alanine.
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| 7. |
- Shariatgorji, Mohammadreza, et al.
(författare)
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Simultaneous imaging of multiple neurotransmitters and neuroactive substances in the brain by desorption electrospray ionization mass spectrometry
- 2016
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Ingår i: NeuroImage. - : Elsevier BV. - 1053-8119 .- 1095-9572. ; 136, s. 129-138
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Tidskriftsartikel (refereegranskat)abstract
- With neurological processes involving multiple neurotransmitters and neuromodulators, it is important to have the ability to directly map and quantify multiple signaling molecules simultaneously in a single analysis. By utilizing a molecular-specific approach, namely desorption electrospray ionization mass spectrometry imaging (DESI-MSI), we demonstrated that the technique can be used to image multiple neurotransmitters and their metabolites (dopamine, dihydroxyphenylacetic acid, 3-methoxytyramine, serotonin, glutamate, glutamine, aspartate,gamma-aminobutyric acid, adenosine) as well as neuroactive drugs (amphetamine, sibutramine, fluvoxamine) and drug metabolites in situ directly in brain tissue sections. The use of both positive and negative ionization modes increased the number of identified molecular targets. Chemical derivatization by charge-tagging the primary amines of molecules significantly increased the sensitivity, enabling the detection of low abundant neurotransmitters and other neuroactive substances previously undetectable by MSI. The sensitivity of the imaging approach of neurochemicals has a great potential in many diverse applications in fields such as neuroscience, pharmacology, drug discovery, neurochemistry, and medicine.
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| 8. |
- Vallianatou, Theodosia, et al.
(författare)
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A mass spectrometry imaging approach for investigating how drug-drug interactions influence drug blood-brain barrier permeability
- 2018
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Ingår i: NeuroImage. - : Elsevier BV. - 1053-8119 .- 1095-9572. ; 172, s. 808-816
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Tidskriftsartikel (refereegranskat)abstract
- There is a high need to develop quantitative imaging methods capable of providing detailed brain localization information of several molecular species simultaneously. In addition, extensive information on the effect of the blood-brain barrier on the penetration, distribution and efficacy of neuroactive compounds is required. Thus, we have developed a mass spectrometry imaging method to visualize and quantify the brain distribution of drugs with varying blood-brain barrier permeability. With this approach, we were able to determine blood-brain barrier transport of different drugs and define the drug distribution in very small brain structures (e.g., choroid plexus) due to the high spatial resolution provided. Simultaneously, we investigated the effect of drug-drug interactions by inhibiting the membrane transporter multidrug resistance 1 protein. We propose that the described approach can serve as a valuable analytical tool during the development of neuroactive drugs, as it can provide physiologically relevant information often neglected by traditional imaging technologies.
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| 9. |
- Vallianatou, Theodosia, et al.
(författare)
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Molecular imaging identifies age-related attenuation of acetylcholine in retrosplenial cortex in response to acetylcholinesterase inhibition
- 2019
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Ingår i: Neuropsychopharmacology. - : Springer Science and Business Media LLC. - 0893-133X .- 1740-634X. ; 44, s. 2091-2098
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Tidskriftsartikel (refereegranskat)abstract
- The neurotransmitter of the cholinergic system, acetylcholine plays a major role in the brain's cognitive function and is involved in neurodegenerative disorders. Here, we present age-related alterations of acetylcholine levels after administration of the acetylcholinesterase inhibitor drug tacrine in normal mice. Using a quantitative, robust and molecular-specific mass spectrometry imaging method we found that tacrine administration significantly raised acetylcholine levels in most areas of sectioned mice brains, inter alia the striatum, hippocampus and cortical areas. However, acetylcholine levels in retrosplenial cortex were significantly lower in 14-month-old than in 12-week-old animals following its administration, indicating that normal aging affects the cholinergic system's responsivity. This small brain region is interconnected with an array of brain networks and is involved in numerous cognitive tasks. Simultaneous visualization of distributions of tacrine and its hydroxylated metabolites in the brain revealed a significant decrease in levels of the metabolites in the 14-month-old mice. The results highlight strengths of the imaging technique to simultaneously investigate multiple molecular species and the drug-target effects in specific regions of the brain. The proposed approach has high potential in studies of neuropathological conditions and responses to neuroactive treatments.
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| 10. |
- Zhang, Xiaoqun, et al.
(författare)
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Striatal Tyrosine Hydroxylase Is Stimulated via TAAR1 by 3-Iodothyronamine, But Not by Tyramine or beta-Phenylethylamine
- 2018
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Ingår i: Frontiers in Pharmacology. - : FRONTIERS MEDIA SA. - 1663-9812. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- The trace amine-associated receptor 1 (TAAR1) is expressed by dopaminergic neurons, but the precise influence of trace amines upon their functional activity remains to be fully characterized. Here, we examined the regulation of tyrosine hydroxylase (TH) by tyramine and beta-phenylethylamine (beta-PEA) compared to 3-iodothyronamine (T(1)AM). Immunoblotting and amperometry were performed in dorsal striatal slices from wildtype (WT) and TAAR1 knockout (KO) mice. T(1)AM increased TH phosphorylation at both Ser(19) and Ser(40), actions that should promote functional activity of TH. Indeed, HPLC data revealed higher rates of L-dihydroxyphenylalanine (DOPA) accumulation in WT animals treated with T(1)AM after the administration of a DOPA decarboxylase inhibitor. These effects were abolished both in TAAR1 KO mice and by the TAAR1 antagonist, EPPTB. Further, they were specific inasmuch as Ser(845) phosphorylation of the post-synaptic GluA1 AMPAR subunit was unaffected. The effects of T1AM on TH phosphorylation at both Ser(19) (CamKII-targeted), and Ser40 (PKA-phosphorylated) were inhibited by KN-92 and H-89, inhibitors of CamKII and PKA respectively. Conversely, there was no effect of an EPAC analog, 8-CPT-2Me-cAMP, on TH phosphorylation. In line with these data, T(1)AM increased evoked striatal dopamine release in TAAR1 WT mice, an action blunted in TAAR1 KO mice and by EPPTB. Mass spectrometry imaging revealed no endogenous T(1)AM in the brain, but detected T(1)AM in several brain areas upon systemic administration in both WT and TAAR1 KO mice. In contrast to T1AM, tyramine decreased the phosphorylation of Ser40-TH, while increasing Ser(845)-GluA1 phosphorylation, actions that were not blocked in TAAR1 KO mice. Likewise, beta-PEA reduced Ser(40)-TH and tended to promote Ser845-GluA1 phosphorylation. The D-1 receptor antagonist SCH23390 blocked tyramine-induced Ser(845)-GluA1 phosphorylation, but had no effect on tyramine-or beta-PEA-induced Ser(40)-TH phosphorylation. In conclusion, by intracellular cascades involving CaMKII and PKA, T(1)AM, but not tyramine and beta-PEA, acts via TAAR1 to promote the phosphorylation and functional activity of TH in the dorsal striatum, supporting a modulatory influence on dopamine transmission.
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