| 1. |
- Madeira, Alexandra, et al.
(författare)
-
Caveolin-1 interacts with alpha-synuclein and mediates toxic actions of cellular alpha-synuclein overexpression
- 2011
-
Ingår i: Neurochemistry International. - : Elsevier BV. - 0197-0186 .- 1872-9754. ; 59:2, s. 280-289
-
Tidskriftsartikel (refereegranskat)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.
|
|
| 2. |
- Madeira, Alexandra, et al.
(författare)
-
Identification of protein-protein interactions by surface plasmon resonance followed by mass spectrometry
- 2011
-
Ingår i: Current protocols in protein science. - Hoboken, NJ, USA : John Wiley & Sons, Inc.. - 1934-3663. ; Suppl. 65, s. 19.21.1-19.21.9
-
Tidskriftsartikel (refereegranskat)abstract
- Elucidation of the function and meaning of the protein networks can be useful in the understanding of many pathological processes and the identification of new therapeutic targets. This unit describes an approach to discover protein-protein interactions by coupling surface plasmon resonance to mass spectrometry. Briefly, a protein is covalently bound to a sensor chip, which is then exposed to brain extracts injected over the surface via a microfluidic system. This allows the monitoring in real-time of the interactions between the immobilized ligand and the extracts. Interacting proteins from the extracts are then recovered, trypsinized, and identified using mass spectrometry. The data obtained are searched against a sequence database using the Mascot software. To exclude nonspecific interactors, control experiments using blank sensor chips, and/or randomized peptides, are performed. The protocol presented here does not require specific labeling or modification of proteins and can be performed in <4 days.
|
|
| 3. |
- Nilsson, Anna, et al.
(författare)
-
Neuropeptidomics of mouse hypothalamus after imipramine treatment reveal somatostatin as a potential mediator of antidepressant effects
- 2012
-
Ingår i: Neuropharmacology. - : Elsevier BV. - 0028-3908 .- 1873-7064. ; 62:1, s. 347-357
-
Tidskriftsartikel (refereegranskat)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.
|
|
| 4. |
- Shariatgorji, Mohammadreza, et al.
(författare)
-
Controlled-pH Tissue Cleanup Protocol for Signal Enhancement of Small Molecule Drugs Analyzed by MALDI-MS Imaging
- 2012
-
Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 1520-6882 .- 0003-2700. ; 84:10, s. 4603-4607
-
Tidskriftsartikel (refereegranskat)abstract
- The limit of detection of low-molecular weight compounds in tissue sections, analyzed by matrix assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI), was significantly improved by employing sample washing using a pH-controlled buffer solution. The pH of the washing solutions were set at values whereby the target analytes would have low solubility. Washing the tissue sections in the buffered solution resulted in removal of endogenous soluble ionization-suppressing compounds and salts, while the target compound remained in situ with minor or no delocalization during the buffered washing procedure. Two pharmaceutical compounds (cimetidine and imipramine) and one new protease inhibitor compound were successfully used to evaluate the feasibility of the pH-controlled tissue washing protocol for MALDI-MSI. Enhancement in signal-to-noise ratio was achieved by a factor of up to 10.
|
|
| 5. |
- Shariatgorji, Mohammadreza, et al.
(författare)
-
Deuterated Matrix-Assisted Laser Desorption Ionization Matrix Uncovers Masked Mass Spectrometry Imaging Signals of Small Molecules
- 2012
-
Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 84:16, s. 7152-7157
-
Tidskriftsartikel (refereegranskat)abstract
- D-4-alpha-Cyano-4-hydroxycinnamic acid (D-4-CHCA) has been synthesized for use as a matrix for matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS) and MALDI-MS imaging (MSI) of small molecule drugs and endogenous compounds. MALDI-MS analysis of small molecules has historically been hindered by interference from matrix ion clusters and fragment peaks that mask signals of low molecular weight compounds of interest. By using D-4-CHCA, the cluster and fragment peaks of CHCA, the most common matrix for analysis of small molecules, are shifted by + 4, + 8 and + 12 Da, which expose signals across areas of the previously concealed low mass range. Here, obscured MALDI-MS signals of a synthetic small molecule pharmaceutical, a naturally occurring isoquinoline alkaloid, and endogenous compounds including the neurotransmitter acetylcholine have been unmasked and imaged directly from biological tissue sections.
|
|
| 6. |
- Shariatgorji, Mohammadreza, et al.
(författare)
-
Direct targeted quantitative molecular imaging of neurotransmitters in brain tissue sections
- 2014
-
Ingår i: Neuron. - : Elsevier BV. - 0896-6273 .- 1097-4199. ; 84:4, s. 697-707
-
Tidskriftsartikel (refereegranskat)abstract
- Current neuroimaging techniques have very limited abilities to directly identify and quantify neurotransmitters from brain sections. We 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, GABA, glutamate, acetylcholine, and L-alpha-glycerylphosphorylcholine, in histological tissue sections at high spatial resolutions. The method is employed to directly measure changes in the absolute and relative levels ofneurotransmitters in specific brain structures in animal disease models and in response to drug treatments, demonstrating the power of mass spectrometry imaging in neuroscience.
|
|
| 7. |
- Shariatgorji, Mohammadreza, et al.
(författare)
-
Mass Spectrometry Imaging, an Emerging Technology in Neuropsychopharmacology
- 2014
-
Ingår i: Neuropsychopharmacology. - : Springer Science and Business Media LLC. - 0893-133X .- 1740-634X. ; 39:1, s. 34-49
-
Forskningsöversikt (refereegranskat)abstract
- Mass spectrometry imaging is a powerful tool for directly determining the distribution of proteins, peptides, lipids, neurotransmitters, metabolites and drugs in neural tissue sections in situ. Molecule-specific imaging can be achieved using various ionization techniques that are suited to different applications but which all yield data with high mass accuracies and spatial resolutions. The ability to simultaneously obtain images showing the distributions of chemical species ranging from metal ions to macromolecules makes it possible to explore the chemical organization of a sample and to correlate the results obtained with specific anatomical features. The imaging of biomolecules has provided new insights into multiple neurological diseases, including Parkinson's and Alzheimer's disease. Mass spectrometry imaging can also be used in conjunction with other imaging techniques in order to identify correlations between changes in the distribution of important chemical species and other changes in the properties of the tissue. Here we review the applications of mass spectrometry imaging in neuroscience research and discuss its potential. The results presented demonstrate that mass spectrometry imaging is a useful experimental method with diverse applications in neuroscience.
|
|
| 8. |
- Zhang, Xiaoqun, et al.
(författare)
-
Distribution, Level, Pharmacology, Regulation, and Signaling of 5-HT6 Receptors in Rats and Marmosets With Special Reference to an Experimental Model of Parkinsonism
- 2011
-
Ingår i: Journal of Comparative Neurology. - : Wiley. - 0021-9967 .- 1096-9861. ; 519:9, s. 1815-1827
-
Tidskriftsartikel (refereegranskat)abstract
- Serotonin 5-HT6 receptors have been implicated in the regulation of cognition, locomotion, and mood, but the elucidation of their functions is complicated by conflicting data using various animal models. Here, a systematic evaluation showed that autoradiographic binding with the selective 5-HT6 receptor antagonist [I-125]SB-258585 was similar in marmosets and rats. In both species, [I-125]SB-258585 binding was enriched in the caudate-putamen. Various recently developed agonists and antagonists toward 5-HT6 receptors exhibited similarities in their abilities to displace [I-125]SB-258585 binding in marmosets and rats. The rank order of pEC50 values were as follows: (+) EMDT-CR = EMD386088 > MS-245 = 5-HT > EMDT >>(-)EMDT-CR; and (+)EMDT-CR = EMD386088 > 5-HT = MS-245 = EMDT >>(-)EMDT-CR, in marmosets and rats, respectively. Unilateral 6-hydroxydopamine lesioning of dopaminergic axons caused a significant decrease of [I-125]SB-258585 binding in the caudate-putamen of both marmosets and rats. Nonetheless, acute administration of the 5-HT6 receptor agonist EMDT to unilaterally 6-hydroxydopamine-lesioned rats, caused an induction of egr-1, homer, and enkephalin mRNAs in the dopamine-depleted hemisphere, indicating a supersensitization of 5-HT6 receptors following dopamine depletion. In conclusion, this study provides evidence for significant similarities in the distribution, level, pharmacology, and regulation of 5-HT6 receptors between rats and marmosets.
|
|
| 9. |
- Domellöf, Magdalena Eriksson, 1977-
(författare)
-
Cognitive and motor dysfunction in the early phase of Parkinson's disease
- 2013
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Parkinson’s disease (PD) is a chronic and progressive neurodegenerative disease. The diagnosis is based on a combination of the motor signs: tremor, bradykinesia, rigidity and postural abnormalities. Mild Cognitive Impairment (MCI) is common early in the disease and a large proportion of patients with PD develop dementia (PDD). Associations between motor symptoms and cognitive decline have been suggested but the results are inconclusive due to differences in the selection of participants and variables tested. Large population based studies with comprehensive neuropsychological investigation in newly diagnosed cases with PD followed prospectively are rare. The aim of this thesis was to improve characterization and understanding of cognition in PD, and to explore the relationship to motor impairment in the early phase of PD.Methods: All new patients with suspected idiopathic parkinsonism in the catchment area (142 ooo inhabitants) were examined during a period of five years and four months. Among other investigations, a comprehensive neuropsychological evaluation was carried out in 119 of 148 patients with PD together with 30 age matched healthy controls. Assessments were repeated after one three and five years.Results: Patients performed worse than healthy controls in a majority of neuropsychological tests. MCI at the time of diagnosis were found in 36% according to recently published MCI criteria. Thirty % were cognitively impaired using another definition. One fourth of the patients developed PDD within five years after diagnosis and 25 % of those with MCI at baseline reversed back to normal cognition. Age and MCI were significant predictors of dementia. Education was an independent predictor for severe cognitive dysfunction at diagnosis but did not predict PDD. Patients with MCI converting to PDD had worse performance on visuospatial function, semantic fluency, episodic memory, mental flexibility and conceptual thinking. There were no differences in cognitive performance between patients with predominant Postural and Gait Disturbances (PIGD) and the tremor dominant subtype at the baseline investigation and belonging to the PIGD subgroup at baseline did not predict PDD. Dementia converters declined more rapidly than non-converters in posture/gait function. Associations between bradykinesia and measures of executive functions and working memory were found, and between posture and gait disturbances and visuospatial function. Some of these associations were persistent after one year. Patients receiving the dopamine agonist pramipexole performed significantly worse on a measure of verbal fluency at the one year follow up.Conclusions: The differences in proportions of cognitively impaired in the different studies emphasize the value of joint criteria for PD-MCI. Even when using such criteria, a substantial proportion of patients revert back to normal function. The increase in motor disability in patients with PDD could have several different causes that need to be further investigated. Associated motor and cognitive dysfunctions could reflect common pathophysiological processes in partly shared networks. Both dopaminergic and non-dopaminergic motor and cognitive functions seems to be involved in PDD which suggests that pharmacological treatment in PD needs to go beyond the scope of dopaminergic deficiency in search for new therapies that would also be effective for non-motor symptoms.
|
|
| 10. |
- Kadkhodaei, Banafsheh, et al.
(författare)
-
Transcription factor Nurr1 maintains fiber integrity and nuclear-encoded mitochondrial gene expression in dopamine neurons
- 2013
-
Ingår i: Proceedings of the National Academy of Sciences. - : Proceedings of the National Academy of Sciences. - 1091-6490 .- 0027-8424. ; 110:6, s. 2360-2365
-
Tidskriftsartikel (refereegranskat)abstract
- Developmental transcription factors important in early neuron specification and differentiation often remain expressed in the adult brain. However, how these transcription factors function to mantain appropriate neuronal identities in adult neurons and how transcription factor dysregulation may contribute to disease remain largely unknown. The transcription factor Nurr1 has been associated with Parkinson's disease and is essential for the development of ventral midbrain dopamine (DA) neurons. We used conditional Nurr1 gene-targeted mice in which Nurr1 is ablated selectively in mature DA neurons by treatment with tamoxifen. We show that Nurr1 ablation results in a progressive pathology associated with reduced striatal DA, impaired motor behaviors, and dystrophic axons and dendrites. We used laser-microdissected DA neurons for RNA extraction and next-generation mRNA sequencing to identify Nurr1-regulated genes. This analysis revealed that Nurr1 functions mainly in transcriptional activation to regulate a battery of genes expressed in DA neurons. Importantly, nuclear-encoded mitochondrial genes were identified as the major functional category of Nurr1-regulated target genes. These studies indicate that Nurr1 has a key function in sustaining high respiratory function in these cells, and that Nurr1 ablation in mice recapitulates early features of Parkinson's disease.
|
|
