| 1. |
- Ekegren, Titti, et al.
(författare)
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Clinical perspectives of high-resolution mass spectrometry-based proteomics in neuroscience: exemplified in amyotrophic lateral sclerosis biomarker discovery research.
- 2008
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Ingår i: Journal of mass spectrometry : JMS. - : Wiley. - 1076-5174 .- 1096-9888. ; 43:5, s. 559-71
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Forskningsöversikt (refereegranskat)abstract
- Biomarker discovery is a central application in today's proteomic research. There is an urgent need for valid biomarkers to improve diagnostic tools and treatment in many disorders, such as the rapidly progressing neurodegenerative disorder amyotrophic lateral sclerosis (ALS) that has a fatal outcome in about 3 years and yet no curative treatment. Screening for clinically relevant biomarkers puts high demands on high-throughput, rapid and precise proteomic techniques. There is a large variety in the methods of choice involving mainly gel-based approaches as well as chromatographic techniques for multi-dimensional protein and peptide separations followed by mass spectrometry (MS) analysis. This special feature article will discuss some important aspects of MS-based clinical proteomics and biomarker discovery in the field of neurodegenerative diseases and ALS research respectively, with the aim to provide a prospective view on current and future research aspects in the field. Furthermore, examples for application of high-resolution MS-based proteomic strategies for ALS biomarker discovery will be demonstrated with two studies previously reported by our group. These studies include among others, utilization of capillary liquid chromatography-Fourier transform ion cyclotron resonance mass spectrometry (LC-FTICR-MS) for advanced protein pattern classification in cerebrospinal fluid (CSF) samples of ALS patients as well as highly sensitive protein identification in minimal amounts of postmortem spinal cord tissue and laser micro-dissected motor neurons using FT-ICR-MS in conjunction with nanoflow LC coupled to matrix-assisted laser desorption ionization time-of-flight tandem mass spectrometry (LC-MALDI-TOF-TOF-MS).
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| 2. |
- Zhu, Changlian, 1964, et al.
(författare)
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X chromosome-linked inhibitor of apoptosis protein reduces oxidative stress after cerebral irradiation or hypoxia-ischemia through up-regulation of mitochondrial antioxidants.
- 2007
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Ingår i: The European journal of neuroscience. - : Wiley. - 1460-9568 .- 0953-816X. ; 26:12, s. 3402-10
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate that X chromosome-linked inhibitor of apoptosis protein (XIAP) counteracts oxidative stress in two essentially different disease-related models of brain injury, hypoxia-ischemia and irradiation, as judged by lower expression of nitrotyrosine (5-fold) and 4-hydroxy-2-nonenal (10-fold) in XIAP-overexpressing compared with wild-type mice. XIAP overexpression induced up-regulation of at least three antioxidants residing in mitochondria, superoxide dismutase 2, thioredoxin 2 and lysine oxoglutarate reductase. Cytochrome c release from mitochondria was reduced in XIAP-overexpressing mice. Hence, in addition to blocking caspases, XIAP can regulate reactive oxygen species in the brain, at least partly through up-regulation of mitochondrial antioxidants. XIAP-induced prevention of oxidative stress was not secondary to tissue protection because although XIAP overexpression provides tissue protection after hypoxia-ischemia, it does not prevent tissue loss after irradiation. This is a previously unknown role of XIAP and may provide the basis for development of novel protective strategies for both acute and chronic neurodegenerative diseases, where oxidative stress is an integral component of the injury mechanisms involved.
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| 3. |
- Rajda, Cecilia, et al.
(författare)
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Increased dopamine content in lymphocytes from high-dose L-Dopa-treated Parkinson's disease patients
- 2005
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Ingår i: Neuroimmunomodulation. - : S. Karger AG. - 1021-7401 .- 1423-0216. ; 12:2, s. 81-84:12, s. 81-84
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: The intracellular (i.c.) content of dopamine and its metabolites was measured in the peripheral blood lymphocytes (PBLs) of Parkinson's disease (PD) patients and healthy controls. METHODS: Catecholamine levels of PBLs were measured using capillary electrophoresis in healthy controls and PD patients receiving different doses of L-dihydroxyphenylalanine (L-Dopa). RESULTS: Higher i.c. dopamine content was found in lymphocytes from PD patients receiving a high dose of L-Dopa (700 +/- 30 mg/day) as compared to lymphocytes from the healthy controls (p = 0.002) and from PD patients treated with a low dose of L-Dopa (400 +/- 30 mg/day) (p = 0.022). The dihydroxyphenylacetic acid to dopamine ratio was significantly lower in the high-dose L-Dopa-treated PD patients than in the controls (p = 0.013). CONCLUSIONS: These findings suggest that the dopamine content and metabolism in the peripheral lymphocytes of PD patients are influenced by L-Dopa administration. This is the first study in which a dose-related effect of L-Dopa treatment was found in lymphocytes from PD patients.
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| 4. |
- Liu, Yawei, et al.
(författare)
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Neuron-mediated generation of regulatory T cells from encephalitogenic T cells suppresses EAE.
- 2006
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Ingår i: Nature Medicine. - : Springer Science and Business Media LLC. - 1546-170X .- 1078-8956. ; 12:5, s. 518-525
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Tidskriftsartikel (refereegranskat)abstract
- Neurons have been neglected as cells with a major immune-regulatory function because they do not express major histocompatibility complex class II. Our data show that neurons are highly immune regulatory, having a crucial role in governing T-cell response and central nervous system (CNS) inflammation. Neurons induce the proliferation of activated CD4+ T cells through B7-CD28 and transforming growth factor (TGF)-beta1–TGF-beta receptor signaling pathways, resulting in amplification of T-cell receptor signaling through phosphorylated ZAP-70, interleukin (IL)-2 and IL-9. The interaction between neurons and T cells results in the conversion of encephalitogenic T cells to CD25+TGF-beta1+CTLA-4+FoxP3+ T regulatory (Treg) cells that suppress encephalitogenic T cells and inhibit experimental autoimmune encephalomyelitis. Suppression is dependent on cytotoxic T lymphocyte antigen (CTLA)-4 but not TGF-beta1. Autocrine action of TGF-beta1, however, is important for the proliferative arrest of Treg cells. Blocking the B7 and TGF-beta pathways prevents the CNS-specific generation of Treg cells. These findings show that generation of neuron-dependent Treg cells in the CNS is instrumental in regulating CNS inflammation.
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| 5. |
- Andersson, Christin, et al.
(författare)
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Differential CSF biomarker levels in APOE-epsilon4-positive and -negative patients with memory impairment.
- 2007
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Ingår i: Dementia and geriatric cognitive disorders. - Basel : S. Karger AG. - 1420-8008 .- 1421-9824. ; 23:2, s. 87-95
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To investigate the relationships between episodic memory, APOE genotype, CSF markers (total tau, T-tau; phospho-tau, P-tau; beta-amyloid, Abeta42) and longitudinal cognitive decline. METHODS: 124 memory clinic patients were retrospectively divided into 6 groups based on (i) episodic memory function (Rey Auditory Verbal Learning Test, RAVLT): severe, moderate or no impairment (SIM, MIM or NIM), and (ii) APOE genotype (epsilon4+ or epsilon4-). CSF marker levels and cognitive decline were compared across groups. RESULTS: Episodic memory function, according to RAVLT scores, was significantly correlated with CSF marker levels only among epsilon4+ subjects and not among epsilon4- subjects. When comparing the 6 subgroups, SIM epsilon4+ and MIM epsilon4+ groups showed significantly lower Abeta42 levels than the other groups. T-tau and P-tau levels were significantly increased in SIM epsilon4+ when compared to all the other groups, including the SIM epsilon4- group. However, both SIM epsilon4+ and SIM epsilon4- declined cognitively during the follow-up. CONCLUSION: It remains to be determined whether APOE genotype affects the expression of biomarkers in CSF, or whether the different biomarker patterns reflect different types of disease processes in patients with progressive cognitive dysfunction.
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| 6. |
- Fernell, Elisabeth, et al.
(författare)
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Aberrant amino acid transport in fibroblasts from children with autism
- 2007
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Ingår i: Neuroscience Letters. - Amsterdam : Elsevier. - 0304-3940 .- 1872-7972. ; 418:1, s. 82-86
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Tidskriftsartikel (refereegranskat)abstract
- Autism is a developmental, cognitive disorder clinically characterized by impaired social interaction, communication and restricted behaviours. The present study was designed to explore whether an abnormality in transport of tyrosine and/or alanine is present in children with autism. Skin biopsies were obtained from 11 children with autism (9 boys and 2 girls) fulfilling the DSM-IV diagnostic criteria for autistic disorder and 11 healthy male control children. Transport of amino acids tyrosine and alanine across the cell membrane of cultured fibroblasts was studied by the cluster tray method. The maximal transport capacity, Vmax and the affinity constant of the amino acid binding sites, Km, were determined. Significantly increased Vmax for alanine (p = 0.014) and increased Km for tyrosine (p = 0.007) were found in children with autism. The increased transport capacity of alanine across the cell membrane and decreased affinity for transport sites of tyrosine indicates the involvement of two major amino acid transport systems (L- and A-system) in children with autism. This may influence the transport of several other amino acids across the blood–brain-barrier. The significance of the findings has to be further explored. © 2007 Elsevier Ireland Ltd. All rights reserved
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| 7. |
- Wallén-Mackenzie, Åsa, et al.
(författare)
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Restricted cortical and amygdaloid removal of vesicular glutamate transporter 2 in preadolescent mice impacts dopaminergic activity and neuronal circuitry of higher brain function.
- 2009
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Ingår i: The Journal of neuroscience : the official journal of the Society for Neuroscience. - 1529-2401 .- 0270-6474. ; 29:7, s. 2238-51
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Tidskriftsartikel (refereegranskat)abstract
- A major challenge in neuroscience is to resolve the connection between gene functionality, neuronal circuits, and behavior. Most, if not all, neuronal circuits of the adult brain contain a glutamatergic component, the nature of which has been difficult to assess because of the vast cellular abundance of glutamate. In this study, we wanted to determine the role of a restricted subpopulation of glutamatergic neurons within the forebrain, the Vglut2-expressing neurons, in neuronal circuitry of higher brain function. Vglut2 expression was selectively deleted in the cortex, hippocampus, and amygdala of preadolescent mice, which resulted in increased locomotor activity, altered social dominance and risk assessment, decreased sensorimotor gating, and impaired long-term spatial memory. Presynaptic VGLUT2-positive terminals were lost in the cortex, striatum, nucleus accumbens, and hippocampus, and a downstream effect on dopamine binding site availability in the striatum was evident. A connection between the induced late-onset, chronic reduction of glutamatergic neurotransmission and dopamine signaling within the circuitry was further substantiated by a partial attenuation of the deficits in sensorimotor gating by the dopamine-stabilizing antipsychotic drug aripiprazole and an increased sensitivity to amphetamine. Somewhat surprisingly, given the restricted expression of Vglut2 in regions responsible for higher brain function, our analyses show that VGLUT2-mediated neurotransmission is required for certain aspects of cognitive, emotional, and social behavior. The present study provides support for the existence of a neurocircuitry that connects changes in VGLUT2-mediated neurotransmission to alterations in the dopaminergic system with schizophrenia-like behavioral deficits as a major outcome.
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| 8. |
- Barg, Sebastian, 1969-, et al.
(författare)
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Granule docking and cargo release in pancreatic β-cells
- 2008
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Ingår i: Biochemical Society Transactions. - 0300-5127 .- 1470-8752. ; 36:Pt 3, s. 294-299
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Tidskriftsartikel (refereegranskat)abstract
- Biphasic insulin secretion is required for proper insulin action and is observed not only in vivo, but also in isolated pancreatic islets and even single beta-cells. Late events in the granule life cycle are thought to underlie this temporal pattern. In the last few years, we have therefore combined live cell imaging and electrophysiology to study insulin secretion at the level of individual granules, as they approach the plasma membrane, undergo exocytosis and finally release their insulin cargo. In the present paper, we review evidence for two emerging concepts that affect insulin secretion at the level of individual granules: (i) the existence of specialized sites where granules dock in preparation for exocytosis; and (ii) post-exocytotic regulation of cargo release by the fusion pore.
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| 9. |
- Lindén, Thomas, 1962, et al.
(författare)
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APOE is a strong gender-dependant risk factor for post-stroke major depression
- 2009
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Ingår i: European Stoke Conference, Stockholm, Maj.
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Konferensbidrag (refereegranskat)abstract
- BACKGROUND: Stroke is a major disease that annually affects 15 million people worldwide. Impaired mood is a common and serious complication. Previous studies indicate that Apolipoprotein E (APOE) alleles differently incur risks for late-life onset depression. The aim of this study was to analyse APOE as a risk factor in men and women for depressive disorders late after stroke. METHODS: Two-hundred and forty-three stroke patients over 70 years of age entered a longitudinal, naturalistic hospital-based study. One hundred and forty nine were assessed for cognitive impairments and depression and 88 were genetically tested one and a half years later. RESULTS: Thirty-three percent had any depression, 15% major depressive disorder. Genotypes 3/2 and 4/2 associated to depression. Major depressive disorder, but not all depression, related strongly to APOE carriership (OR 6.0; 95%CI 1.6 to 22), and was stronger for women (OR 17: 95% CI 1.6 to 174) than for men. CONCLUSION: In this first study to analyse the association between APOE genotypes and post-stroke depression, we found that APOE increased the risk for depression, especially in women. The results call for further studies to confirm and clarify the mechanisms for these effects as well as for the difference between sexes.
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| 10. |
- Westermark, Gunilla T., et al.
(författare)
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Serum amyloid A and protein AA : molecular mechanisms of a transmissible amyloidosis
- 2009
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Ingår i: FEBS Letters. - : Wiley. - 0014-5793 .- 1873-3468. ; 583:16, s. 2685-2690
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Forskningsöversikt (refereegranskat)abstract
- Systemic AA-amyloidosis is a complication of chronic inflammatory diseases and the fibril protein AA derives from the acute phase reactant serum AA. AA-amyloidosis can be induced in mice by an inflammatory challenge. The lag phase before amyloid develops can be dramatically shortened by administration of a small amount of amyloid fibrils. Systemic AA-amyloidosis is transmissible in mice and may be so in humans. Since transmission can cross species barriers it is possible that AA-amyloidosis can be induced by amyloid in food, e.g. foie gras. In mice, development of AA-amyloidosis can also be accelerated by other components with amyloid-like properties. A new possible risk factor may appear with synthetically made fibrils from short peptides, constructed for tissue repair.
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