| 1. |
- He, Yachao, et al.
(author)
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Prosaposin maintains lipid homeostasis in dopamine neurons and counteracts experimental parkinsonism in rodents
- 2023
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In: Nature Communications. - : Springer Nature. - 2041-1723. ; 14
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Journal article (peer-reviewed)abstract
- Prosaposin (PSAP) modulates glycosphingolipid metabolism and variants have been linked to Parkinson's disease (PD). Here, we find altered PSAP levels in the plasma, CSF and post-mortem brain of PD patients. Altered plasma and CSF PSAP levels correlatewith PD-relatedmotor impairments. Dopaminergic PSAP-deficient (cPSAP(DAT)) mice display hypolocomotion and depression/anxiety-like symptoms with mildly impaired dopaminergic neurotransmission, while serotonergic PSAP-deficient (cPSAP(SERT)) mice behave normally. Spatial lipidomics revealed an accumulation of highly unsaturated and shortened lipids and reduction of sphingolipids throughout the brains of cPSAP(DAT) mice. The overexpression of alpha-synuclein via AAV lead to more severe dopaminergic degeneration and higher p-Ser129 alpha-synuclein levels in cPSAP(DAT) mice compared to WT mice. Overexpression of PSAP via AAV and encapsulated cell biodelivery protected against 6-OHDA and alpha-synuclein toxicity in wild-type rodents. Thus, these findings suggest PSAP may maintain dopaminergic lipid homeostasis, which is dysregulated in PD, and counteract experimental parkinsonism.
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| 2. |
- Hulme, Heather, et al.
(author)
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Simultaneous mass spectrometry imaging of multiple neuropeptides in the brain and alterations induced by experimental parkinsonism and L-DOPA therapy
- 2020
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In: Neurobiology of Disease. - : ACADEMIC PRESS INC ELSEVIER SCIENCE. - 0969-9961 .- 1095-953X. ; 137
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Journal article (peer-reviewed)abstract
- Neuropeptides are important signalling molecules in the brain and alterations in their expression levels have been linked to neurological disorders such as Parkinson's disease. It is challenging to map neuropeptide changes across and within brain regions because of their low in vivo concentrations and complex post-translational processing. Consequently, the role of neuropeptides in Parkinson's disease is not well understood. Thus, we have developed and evaluated a method to image multiple neuropeptides simultaneously in both rat and primate brain tissue sections by matrix-assisted laser desorption/ionisation mass spectrometry imaging at high lateral resolution. Using a unilateral 6-hydroxydopamine rat model of Parkinson's disease, we imaged changes in enkephalins, dynorphins, tachykinins and neurotensin associated with the dopaminergic denervation and L-DOPA treatment in multiple brain regions. L-DOPA administration significantly affected neuropeptides in the globus pallidus, while neuropeptides in the caudate-putamen were mostly affected by dopamine depletion. Using high lateral resolution imaging, we observed an increase of neurotensin in the dorsal sub-region of the globus pallidus after dopamine depletion. This study highlights the capacity of mass spectrometry imaging to elucidate the dynamics of neuropeptide signalling during Parkinson's disease and its treatment.
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| 3. |
- Kaya, Ibrahim, et al.
(author)
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On-Tissue Chemical Derivatization for Comprehensive Mapping of Brain Carboxyl and Aldehyde Metabolites by MALDI-MS Imaging
- 2023
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In: Journal of the American Society for Mass Spectrometry. - : American Chemical Society (ACS). - 1044-0305 .- 1879-1123. ; 34:5, s. 836-846
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Journal article (peer-reviewed)abstract
- The visualization of small metabolites by MALDI mass spectrometry imaging in brain tissue sections is challenging due to low detection sensitivity and high background interference. We present an on-tissue chemical derivatization MALDI mass spectrometry imaging approach for the comprehensive mapping of carboxyls and aldehydes in brain tissue sections. In this approach, the AMPP (1-(4-(aminomethyl)phenyl)pyridin-1-ium chloride) derivatization reagent is used for the covalent charge-tagging of molecules containing carboxylic acid (in the presence of peptide coupling reagents) and aldehydes. This includes free fatty acids and the associated metabolites, fatty aldehydes, dipeptides, neurotoxic reactive aldehydes, amino acids, neurotransmitters and associated metabolites, as well as tricarboxylic acid cycle metabolites. We performed sensitive ultrahigh mass resolution MALDI-MS detection and imaging of various carboxyl-and aldehyde containing endogenous metabolites simultaneously in rodent brain tissue sections. We verified the AMPP-derivatized metabolites by tandem MS for structural elucidation. This approach allowed us to image numerous aldehydes and carboxyls, including certain metabolites which had been undetectable in brain tissue sections. We also demonstrated the application of on-tissue derivatization to carboxyls and aldehydes in coronal brain tissue sections of a nonhuman primate Parkinson's disease model. Our methodology provides a powerful tool for the sensitive, simultaneous spatial molecular imaging of numerous aldehydes and carboxylic acids during pathological states, including neurodegeneration, in brain tissue.
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| 4. |
- Madeira, Alexandra, et al.
(author)
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Caveolin-1 interacts with alpha-synuclein and mediates toxic actions of cellular alpha-synuclein overexpression
- 2011
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In: Neurochemistry International. - : Elsevier BV. - 0197-0186 .- 1872-9754. ; 59:2, s. 280-289
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Journal article (peer-reviewed)abstract
- Caveolin-1 (Cav-1) is a transmembrane protein which clusters proteins and lipids at the cell membrane into a subclass of lipid rafts named caveolae. To increase our understanding about putative functions of Cav-1 in neuronal cells, we used mouse brain extracts and a novel technology coupling surface plasmon resonance to mass spectrometry to find binding partners to Cav-1. An interaction between Cav-1 and alpha-synclein was found and confirmed in reciprocal pulldown experiments. Genetic overexpression of alpha-synclein in mouse neuroblastoma Neuro2A cells (N2A) expectedly decreased cell survival, but also significantly increased the levels of Cav-1. Furthermore, si-RNA-mediated knockdown of Cav-1 counteracted cell death induced by overexpression of alpha-synuclein. We also used an inhibitor of proteasome (MG132) to induce cell death in a Parkinson's disease context. Cav-1 knockdown had no effect on cell death induced by MG132. Conversely, treating the cells with mevastatin, an inhibitor of cholesterol synthesis, inhibits cell death induced by MG132, but not by alpha synuclein overexpression. It can be concluded that Cav-1 may play a functional role in neuronal cells by virtue of its physical interaction with alpha-synuclein and regulate alpha synuclein-mediated actions on cell death, processes known to be involved in synucleinopathies including Parkinson's disease.
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| 5. |
- Mantas, Ioannis, et al.
(author)
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TAAR1-Dependent and-Independent Actions of Tyramine in Interaction With Glutamate Underlie Central Effects of Monoamine Oxidase Inhibition
- 2021
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In: Biological Psychiatry. - : Elsevier. - 0006-3223 .- 1873-2402. ; 90:1, s. 16-27
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Journal article (peer-reviewed)abstract
- BACKGROUND: Monoamine oxidase inhibitors (MAOIs) exert therapeutic actions by elevating extracellular levels of monoamines in the brain. Irreversible MAOIs cause serious hypertensive crises owing to peripheral accumulation of tyramine, but the role of tyramine in the central effects of MAOIs remains elusive, an issue addressed herein. To achieve robust inhibition of MAOA/B, the clinically used antidepressant tranylcypromine (TCP) was employed. METHODS: Behavioral, histological, mass spectrometry imaging, and biosensor-mediated measures of glutamate were conducted with MAOIs in wild-type and TAAR1-knockout (KO) mice. RESULTS: Both antidepressant and locomotion responses to TCP were enhanced in TAAR1-KO mice. A recently developed fluoromethylpyridinium-based mass spectrometry imaging method revealed robust accumulation of striatal tyramine on TCP administration. Furthermore, tyramine accumulation was higher in TAAR1-KO versus wild type mice, suggesting a negative feedback mechanism for TAAR1 in sensing tyramine levels. Combined histoenzymological and immunohistological studies revealed hitherto unknown TAAR1 localization in brain areas projecting to the substantia nigra/ventral tegmental area. Using an enzyme-based biosensor technology, we found that both TCP and tyramine reduced glutamate release in the substantia nigra in wild-type but not in TAAR1-KO mice. Moreover, glutamate measures in freely moving animals treated with TCP demonstrated that TAAR1 prevents glutamate accumulation in the substantia nigra during hyperlocomotive states. CONCLUSIONS: These observations suggest that tyramine, in interaction with glutamate, is involved in centrally mediated behavioral, transcriptional, and neurochemical effects of MAOIs.
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| 6. |
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| 7. |
- Nilsson, Anna, et al.
(author)
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Increased striatal mRNA and protein levels of the immunophilin FKBP-12 in experimental Parkinson’s Disease and identification of FKBP-12-binding proteins
- 2007
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In: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 6:10, s. 3952-3961
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Journal article (peer-reviewed)abstract
- FKBP-12, a 12 kDa FK506-binding protein (neuroimmunophilin), acts as a receptor for the immunosuppressant drug FK506. Neuroimmunophilins, including FKBP-12, are abundant in the brain and have been shown to be involved in reversing neuronal degeneration and preventing cell death. In this report, we have utilized several analytical techniques, such as in situ hybridization, Western blotting, two-dimensional gel electrophoresis, and liquid chromatography electrospray tandem mass spectrometry to study the transcriptional expression as well as protein levels of FKBP-12 in the unilateral 6-hydroxydopamine (6-OHDA) rat model of Parkinson's disease. The FKBP-12 protein was also detected directly on brain tissue sections using mass spectrometry profiling. We found increased levels of FKBP-12 mRNA and protein in the dorsal and middle part of the 6-OHDA lesioned striatum. Thus, these studies clearly demonstrate that FKBP-12 is increased in the brain of a common animal model of Parkinson's disease (PD). Additionally, we have identified potential binding partners to FKBP-12 that may be implicated in the pathophysiology of Parkinson's disease, such as alpha-enolase, 14-3-3 zeta/delta, pyruvate kinase isozymes, and heat shock protein 70, using surface plasmon resonance sensor technology in combination with mass spectrometry. In conclusion, these data strongly suggests that FKBP-12 is altered in an experimental model of PD.
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| 8. |
- Nilsson, Anna, et al.
(author)
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Neuropeptidomics of mouse hypothalamus after imipramine treatment reveal somatostatin as a potential mediator of antidepressant effects
- 2012
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In: Neuropharmacology. - : Elsevier BV. - 0028-3908 .- 1873-7064. ; 62:1, s. 347-357
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Journal article (peer-reviewed)abstract
- Excessive activation of the hypothalamic pituitary adrenal (HPA) axis has been associated with numerous diseases, including depression, and the tricyclic antidepressant imipramine has been shown to suppress activity of the HPA axis. Central hypothalamic control of the HPA axis is complex and involves a number of neuropeptides released from multiple hypothalamic subnuclei. The present study was therefore designed to determine the effects of imipramine administration on the mouse hypothalamus using a peptidomics approach. Among the factors found to be downregulated after acute (one day) or chronic (21 days) imipramine administration were peptides derived from secretogranin 1 (chromogranin B) as well as peptides derived from cerebellin precursors. In contrast, peptides SRIF-14 and SRIF-28 (1-11) derived from somatostatin (SRIF, somatotropin release inhibiting factor) were significantly upregulated by imipramine in the hypothalamus. Because diminished SRIF levels have long been known to occur in depression, a second part of the study investigated the roles of individual SRIF receptors in mediating potential antidepressant effects. SRA880, an antagonist of the somatostatin-1 autoreceptor (sst1) which positively modulates release of endogenous SRIF, was found to synergize with imipramine in causing antidepressant-like effects in the tail suspension test. Furthermore, chronic co-administration of SRA880 and imipramine synergistically increased BDNF mRNA expression in the cerebral cortex. Application of SRIF or L054264, an sst2 receptor agonist, but not 1,803807, an sst4 receptor agonist, increased phosphorylation of CaMKII and GluR1 in cerebrocortical slices. Our present experiments thus provide evidence for antidepressant-induced upregulation of SRIF in the brain, and strengthen the notion that augmented SRIF expression and signaling may counter depressive-like symptoms.
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| 9. |
- Nilsson, Anna, et al.
(author)
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Striatal alterations of secretogranin-1, somatostatin, prodynorphin and cholecystokinin peptides in an experimental mouse model of Parkinson’s disease
- 2009
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In: Molecular & Cellular Proteomics. - 1535-9476 .- 1535-9484. ; 8:5, s. 1094-1104
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Journal article (peer-reviewed)abstract
- The principal causative pathology of Parkinson disease is the progressive degeneration of dopaminergic neurons in the substantia nigra pars compacta projecting to the striatum in the brain. The information regarding the expression of neuropeptides in parkinsonism is very limited. Here we have elucidated striatal neuropeptide mechanisms in experimental parkinsonism using the unilateral 6-hydroxydopamine model to degenerate dopamine neurons. A thoroughly controlled sample preparation technique together with a peptidomics approach and targeted neuropeptide sequence collections enabled sensitive detection, identification, and relative quantitation of a great number of endogenous neuropeptides. Previously not recognized alterations in neuropeptide levels were identified in the unilateral lesioned mice with or without subchronic 3,4-dihydroxy-L-phenylalanine administration, the conventional treatment of Parkinson disease. Several of these peptides originated from the same precursor such as secretogranin-1, somatostatin, prodynorphin, and cholecystokinin. Disease-related biotransformation of precursors into individual peptides was observed in the experimental model of Parkinson disease. Several previously unreported potentially biologically active peptides were also identified from the striatal samples. This study provides further evidence that neuropeptides take part in mediating the central nervous system failure associated with Parkinson disease.
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| 10. |
- Paslawski, Wojciech, et al.
(author)
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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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In: 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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Journal article (peer-reviewed)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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