| 1. |
|
|
| 2. |
- Mattsson, Niklas, 1979, et al.
(författare)
-
Amyloid-β metabolism in Niemann-Pick C disease models and patients.
- 2012
-
Ingår i: Metabolic brain disease. - : Springer Science and Business Media LLC. - 1573-7365 .- 0885-7490. ; 27:4, s. 573-85
-
Tidskriftsartikel (refereegranskat)abstract
- Niemann-Pick type C (NPC) is a progressive neurodegenerative lysosomal disease with altered cellular lipid trafficking. The metabolism of amyloid-β (Aβ) - previously mainly studied in Alzheimer's disease - has been suggested to be altered in NPC. Here we aimed to perform a detailed characterization of metabolic products from the amyloid precursor protein (APP) in NPC models and patients. We used multiple analytical technologies, including immunoassays and immunoprecipitation followed by mass spectrometry (IP-MS) to characterize Aβ peptides and soluble APP fragments (sAPP-α/β) in cell media from pharmacologically (U18666A) and genetically (NPC1 ( -/- ) ) induced NPC cell models, and cerebrospinal fluid (CSF) from NPC cats and human patients. The pattern of Aβ peptides and sAPP-α/β fragments in cell media was differently affected by NPC-phenotype induced by U18666A treatment and by NPC1 ( -/- ) genotype. U18666A treatment increased the secreted media levels of sAPP-α, AβX-40 and AβX-42 and reduced the levels of sAPP-β, Aβ1-40 and Aβ1-42, while IP-MS showed increased relative levels of Aβ5-38 and Aβ5-40 in response to treatment. NPC1 ( -/- ) cells had reduced media levels of sAPP-α and Aβ1-16, and increased levels of sAPP-β. NPC cats had altered CSF distribution of Aβ peptides compared with normal cats. Cats treated with the potential disease-modifying compound 2-hydroxypropyl-β-cyclodextrin had increased relative levels of short Aβ peptides including Aβ1-16 compared with untreated cats. NPC patients receiving β-cyclodextrin had reduced levels over time of CSF Aβ1-42, AβX-38, AβX-40, AβX-42 and sAPP-β, as well as reduced levels of the axonal damage markers tau and phosphorylated tau. We conclude that NPC models have altered Aβ metabolism, but with differences across experimental systems, suggesting that NPC1-loss of function, such as in NPC1 ( -/- ) cells, or NPC1-dysfunction, seen in NPC patients and cats as well as in U18666A-treated cells, may cause subtle but different effects on APP degradation pathways. The preliminary findings from NPC cats suggest that treatment with cyclodextrin may have an impact on APP processing pathways. CSF Aβ, sAPP and tau biomarkers were dynamically altered over time in human NPC patients.
|
|
| 3. |
- Abramsson, Alexandra, 1973, et al.
(författare)
-
Proteomics Profiling of Single Organs from Individual Adult Zebrafish.
- 2010
-
Ingår i: Zebrafish. - : Mary Ann Liebert Inc. - 1557-8542 .- 1545-8547. ; 7:2, s. 161-168
-
Tidskriftsartikel (refereegranskat)abstract
- Abstract The model organism zebrafish (Danio rerio) is extensively utilized in studies of developmental biology but is also being investigated in the context of a growing list of human age-related diseases. To facilitate such studies, we here present protein expression patterns of adult zebrafish organs, including blood, brain, fin, heart, intestine, liver, and skeletal muscle. Protein extracts were prepared from the different organs of two zebrafish and analyzed using liquid chromatography coupled to high-resolution tandem mass spectrometry. Zebrafish tissue was digested directly after minimal fractionation and cleaned up (the shotgun approach). Proteins were identified using Mascot software. In total, 1394 proteins were identified of which 644 were nonredundant. Of these, 373 demonstrated an organ-specific expression pattern and 57 had not been shown on protein level before. These data emphasize the need for increased research at the protein level to facilitate the selection of candidate proteins for targeted quantification and to refine systematic genetic network analysis in vertebrate development, biology, and disease.
|
|
| 4. |
- Augutis, Kristin, et al.
(författare)
-
Cerebrospinal fluid biomarkers of β-amyloid metabolism in multiple sclerosis.
- 2013
-
Ingår i: Multiple sclerosis (Houndmills, Basingstoke, England). - : SAGE Publications. - 1477-0970 .- 1352-4585. ; 19:5, s. 543-52
-
Tidskriftsartikel (refereegranskat)abstract
- Amyloid precursor protein (APP) and amyloid β (Aβ) peptides are intensely studied in neuroscience and their cerebrospinal fluid (CSF) measurements may be used to track the metabolic pathways of APP in vivo. Reduced CSF levels of Aβ and soluble APP (sAPP) fragments are reported in inflammatory diseases, including multiple sclerosis (MS); but in MS, the precise pathway of APP metabolism and whether it can be affected by disease-modifying treatments remains unclear.
|
|
| 5. |
- Brinkmalm, Gunnar, et al.
(författare)
-
An online nano-LC-ESI-FTICR-MS method for comprehensive characterization of endogenous fragments from amyloid β and amyloid precursor protein in human and cat cerebrospinal fluid.
- 2012
-
Ingår i: Journal of mass spectrometry : JMS. - : Wiley. - 1096-9888 .- 1076-5174. ; 47:5, s. 591-603
-
Tidskriftsartikel (refereegranskat)abstract
- Amyloid precursor protein (APP) is the precursor protein to amyloid β (Aβ), the main constituent of senile plaques in Alzheimer's disease (AD). Endogenous Aβ peptides reflect the APP processing, and greater knowledge of different APP degradation pathways is important to understand the mechanism underlying AD pathology. When one analyzes longer Aβ peptides by low-energy collision-induced dissociation tandem mass spectrometry (MS/MS), mainly long b-fragments are observed, limiting the possibility to determine variations such as amino acid variants or post-translational modifications (PTMs) within the N-terminal half of the peptide. However, by using electron capture dissociation (ECD), we obtained a more comprehensive sequence coverage for several APP/Aβ peptide species, thus enabling a deeper characterization of possible variants and PTMs. Abnormal APP/Aβ processing has also been described in the lysosomal storage disease Niemann-Pick type C and the major large animal used for studying this disease is cat. By ECD MS/MS, a substitution of Asp7 → Glu in cat Aβ was identified. Further, sialylated core 1 like O-glycans at Tyr10, recently discovered in human Aβ (a previously unknown glycosylation type), were identified also in cat cerebrospinal fluid (CSF). It is therefore likely that this unusual type of glycosylation is common for (at least) species belonging to the magnorder Boreoeutheria. We here describe a detailed characterization of endogenous APP/Aβ peptide species in CSF by using an online top-down MS-based method.
|
|
| 6. |
- Brinkmalm-Westman, Ann, 1966, et al.
(författare)
-
SILAC zebrafish for quantitative analysis of protein turnover and tissue regeneration.
- 2011
-
Ingår i: Journal of proteomics. - : Elsevier BV. - 1876-7737 .- 1874-3919. ; 75:2, s. 425-34
-
Tidskriftsartikel (refereegranskat)abstract
- Defective tissue regeneration is thought to contribute to several human diseases, including neurodegenerative disorders, heart failure and various lung diseases. Boosting the regenerative capacity has been suggested a possible therapeutic approach. Methods to metabolically label newly synthesized proteins in vivo with stable isotopic forms of amino acids holds promise for the study of protein turnover and tissue regeneration that are fundamental to the sustained life of all organisms. Here, we used the "stable isotope labeling with amino acids in cell culture" (SILAC) approach to explore normal protein turnover and tissue regeneration in adult zebrafish. The ratio of labeled and unlabeled proteins/peptides in specific organs of zebrafish fed a SILAC diet containing (13)C(6)-labeled lysine was determined by liquid chromatography and tandem mass spectrometry. Labeling was highest in tissues with high regenerative capacity, including intestine, liver, and fin, whereas brain and heart displayed the lowest labeling. Proteins with high degree of labeling were mainly involved in catalytic or transport activity pathways. The technique also verified increased protein synthesis during regeneration of the caudal fin following amputation. This newly developed SILAC zebrafish model constitutes a novel tool to analyze tissue regeneration in an animal model amenable to genetic and pharmacologic manipulation.
|
|
| 7. |
- Johansson, Oskar N., 1984, et al.
(författare)
-
A quick and robust method for quantification of the hypersensitive response in plants
- 2015
-
Ingår i: Peerj. - : PeerJ. - 2167-8359. ; 3
-
Tidskriftsartikel (refereegranskat)abstract
- One of the most studied defense reactions of plants against microbial pathogens is the hypersensitive response (HR). The HR is a complex multicellular process that involves programmed cell death at the site of infection. A standard method to quantify plant defense and the HR is to measure the release of cellular electrolytes into water after infiltration with pathogenic bacteria. In this type of experiment, the bacteria are typically delivered into the plant tissue through syringe infiltration. Here we report the development of a vacuum infiltration protocol that allows multiple plant lines to be infiltrated simultaneously and assayed for defense responses. Vacuum infiltration did not induce more wounding response in Arabidopsis leaf tissue than syringe inoculation, whereas throughput and reproducibility were improved. The method was used to study HR-induced electrolyte loss after treatment with the bacterium Pseudomonas syringae pv. tomato DC3000 harboring the effector AvrRpm1, AvrRpt2 or AvrRps4. Specifically, the influence of bacterial titer on AvrRpm1-induced HR was investigated. Not only the amplitude, but also the timing of the maximum rate of the HR reaction was found to be dose-dependent. Finally, using vacuum infiltration, we were able quantify induction of phospholipase D activity after AvrRpm1 recognition in leaves labeled with (PO4)-P-33.
|
|
| 8. |
- Mattsson, Niklas, 1979, et al.
(författare)
-
BACE1 inhibition induces a specific cerebrospinal fluid β-amyloid pattern that identifies drug effects in the central nervous system.
- 2012
-
Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 7:2
-
Tidskriftsartikel (refereegranskat)abstract
- BACE1 is a key enzyme for amyloid-β (Aβ) production, and an attractive therapeutic target in Alzheimer's disease (AD). Here we report that BACE1 inhibitors have distinct effects on neuronal Aβ metabolism, inducing a unique pattern of secreted Aβ peptides, analyzed in cell media from amyloid precursor protein (APP) transfected cells and in cerebrospinal fluid (CSF) from dogs by immunoprecipitation-mass spectrometry, using several different BACE1 inhibitors. Besides the expected reductions in Aβ1-40 and Aβ1-42, treatment also changed the relative levels of several other Aβ isoforms. In particular Aβ1-34 decreased, while Aβ5-40 increased, and these changes were more sensitive to BACE1 inhibition than the changes in Aβ1-40 and Aβ1-42. The effects on Aβ5-40 indicate the presence of a BACE1 independent pathway of APP degradation. The described CSF Aβ pattern may be used as a pharmacodynamic fingerprint to detect biochemical effects of BACE1-therapies in clinical trials, which might accelerate development of novel therapies.
|
|
| 9. |
- Mattsson, Niklas, 1979, et al.
(författare)
-
Longitudinal cerebrospinal fluid biomarkers over four years in mild cognitive impairment.
- 2012
-
Ingår i: Journal of Alzheimer's disease : JAD. - 1875-8908 .- 1387-2877. ; 30:4, s. 767-78
-
Tidskriftsartikel (refereegranskat)abstract
- Cerebrospinal fluid (CSF) measurements of amyloid-β42 (Aβ42), total-tau (T-tau), and phosphorylated tau (P-tau) may be used to predict future Alzheimer's disease (AD) dementia in patients with mild cognitive impairment (MCI). The precise temporal development of these biomarkers in relation to clinical progression is unclear. Earlier studies have been hampered by short follow-up. In an MCI cohort, we selected 15 patients who developed AD (MCI-AD) and 15 who remained cognitively stable during 4 years of follow-up. CSF was sampled at three serial occasions from each patient and analyzed for Aβ peptides, the soluble amyloid-β protein precursor protein fragments sAβPPα and sAβPPβ, T-tau, P-tau, and chromogranin B, which is a protein linked to regulated neuronal secretion. We also measured, for the first time in MCI patients, an extended panel of Aβ peptides by matrix-assisted-laser-desorption/ionization time-of-flight mass spectrometry (MS). Most biomarkers were surprisingly stable over the four years with coefficients of variation below or close to 10%. However, MCI-AD patients decreased in CSF AβX₋₄₀ and chromogranin B concentrations, which may indicate a reduced number of functional neurons or synapses with disease progression. The MS Aβ peptide panel was more useful than any single Aβ peptide to identify MCI-AD patients already at baseline. Knowledge on these biomarkers and their trajectories may facilitate early diagnosis of AD and be useful in future clinical trials to track effects of disease modifying drugs.
|
|
| 10. |
- Mustafiz, Tamanna, et al.
(författare)
-
Characterization of the brain β-amyloid isoform pattern at different ages of Tg2576 mice.
- 2011
-
Ingår i: Neuro-degenerative diseases. - : S. Karger AG. - 1660-2862 .- 1660-2854. ; 8:5, s. 352-63
-
Tidskriftsartikel (refereegranskat)abstract
- Although genetic and biochemical studies have suggested a cardinal role for β-amyloid (Aβ) in Alzheimer's disease, the underlying mechanism(s) of how Aβ induces neurodegeneration is still unclear. Our objective was to investigate the consequences of Aβ, especially on tau phosphorylation at specific epitopes important for Alzheimer's disease.
|
|
