| 1. |
- Brännström, Kristoffer, et al.
(författare)
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A Generic Method for Design of Oligomer-Specific Antibodies
- 2014
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:3, s. e90857-
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Tidskriftsartikel (refereegranskat)abstract
- Antibodies that preferentially and specifically target pathological oligomeric protein and peptide assemblies, as opposed to their monomeric and amyloid counterparts, provide therapeutic and diagnostic opportunities for protein misfolding diseases. Unfortunately, the molecular properties associated with oligomer-specific antibodies are not well understood, and this limits targeted design and development. We present here a generic method that enables the design and optimisation of oligomer-specific antibodies. The method takes a two-step approach where discrimination between oligomers and fibrils is first accomplished through identification of cryptic epitopes exclusively buried within the structure of the fibrillar form. The second step discriminates between monomers and oligomers based on differences in avidity. We show here that a simple divalent mode of interaction, as within e. g. the IgG isotype, can increase the binding strength of the antibody up to 1500 times compared to its monovalent counterpart. We expose how the ability to bind oligomers is affected by the monovalent affinity and the turnover rate of the binding and, importantly, also how oligomer specificity is only valid within a specific concentration range. We provide an example of the method by creating and characterising a spectrum of different monoclonal antibodies against both the A beta peptide and alpha-synuclein that are associated with Alzheimer's and Parkinson's diseases, respectively. The approach is however generic, does not require identification of oligomer-specific architectures, and is, in essence, applicable to all polypeptides that form oligomeric and fibrillar assemblies.
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| 2. |
- Dobbins, Sara E., et al.
(författare)
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Common variation at 10p12.31 near MLLT10 influences meningioma risk
- 2011
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Ingår i: Nature Genetics. - London : Nature America, Inc.. - 1061-4036 .- 1546-1718. ; 43:9, s. 825-827
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Tidskriftsartikel (refereegranskat)abstract
- To identify susceptibility loci for meningioma, we conducted a genome-wide association study of 859 affected individuals (cases) and 704 controls with validation in two independent sample sets totaling 774 cases and 1,764 controls. We identified a new susceptibility locus for meningioma at 10p12.31 (MLLT10, rs11012732, odds ratio = 1.46, P(combined) = 1.88 x 10(-14)). This finding advances our understanding of the genetic basis of meningioma development.
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| 3. |
- Ahmadi, Mahboobah, et al.
(författare)
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Human extraocular muscles in ALS
- 2010
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Ingår i: Investigative Ophthalmology and Visual Science. - : Association for Research in Vision and Ophthalmology (ARVO). - 0146-0404 .- 1552-5783. ; 51:7, s. 3494-3501
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE. To investigate the general morphology, fiber type content, and myosin heavy chain (MyHC) composition of extraocular muscles (EOMs) from postmortem donors with amyotrophic lateral sclerosis (ALS) and to evaluate whether EOMs are affected or truly spared in this disease. METHODS. EOM and limb muscle samples obtained at autopsy from ALS donors and EOM samples from four control donors were processed for immunohistochemistry with monoclonal antibodies against distinct MyHC isoforms and analyzed by SDS-PAGE. In addition, hematoxylin and eosin staining and nicotinamide tetrazolium reductase (NADH-TR) activity were studied. RESULTS. Wide heterogeneity was observed in the appearance of the different EOMs from each single donor and between donors, irrespective of ALS type or onset. Pathologic morphologic findings in ALS EOMs included presence of atrophic and hypertrophic fibers, either clustered in groups or scattered; increased amounts of connective tissue; and areas of fatty replacement. The population of fibers stained with anti-MyHCslow tonic was smaller than that of MyHCIpositive fibers and was mostly located in the orbital layer in most of the ALS EOM samples, whereas an identical staining pattern for both fiber populations was observed in the control specimens. MyHCembryonic was notably absent from the ALS EOMs. CONCLUSIONS. The EOMs showed signs of involvement with altered fiber type composition, contractile protein content, and cellular architecture. However, when compared to the limb muscles, the EOMs were remarkably preserved. EOMs are a useful model for the study of the pathophysiology of ALS.
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| 4. |
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| 5. |
- Bergemalm, Daniel, 1977-
(författare)
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Mutant superoxide dismutase-1-caused pathogenesis in amyotrophic lateral sclerosis
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Amyotrophic lateral sclerosis (ALS) is a devastating disease that affects people in their late mid-life, with fatal outcome usually within a few years. The progressive degeneration of neurons responsible for muscle movement (motor neurons) throughout the central nervous system (CNS) leads to muscle wasting and paralysis, and eventually affects respiratory function. Most cases have no familial background (sporadic) whereas about 10% of cases have relatives affected by the disease. A substantial number of familial cases are caused by mutations in the gene encoding superoxide dismutase-1 (SOD1). Since the initial discovery of this relationship about 17 years ago, numerous workers have tried to identify the pathogenicity of mutant SOD1 but without any final agreement or consensus regarding mechanism. The experiments in this thesis have been aimed at finding common pathogenic mechanisms by analyzing transgenic mouse models expressing mutant SOD1s with widely different properties. Mitochondrial pathology and dysfunction have been reported in both ALS patients and murine models. We used density gradient ultracentrifugation for comparison of mitochondrial partitioning of SOD1 in our transgenic models. It was found that models with high levels of mutant protein, overloaded mitochondria with high levels of SOD1-protein whereas models with wild type-like levels of mutant protein did not. No significant association of the truncation mutant G127X with mitochondria was found. Thus, if mitochondrial dysfunction and pathology are fundamental for ALS pathogenesis this is unlikely to be caused by physical association of mutant SOD1 with mitochondria. Density gradient ultracentrifugation was used to study SOD1 inclusions in tissues from an ALS patient with a mutant SOD1 (G127X). We found large amounts in the ventral horns of the spinal cord but also in the liver and kidney, although at lower levels. This showed that such signs of the disease can also be found outside the CNS. This method was used further to characterize SOD1 inclusions with regard to the properties of mutant SOD1 and the presence of other proteins. The inclusions were found to be complex detergent-sensitive structures with mutant SOD1 reduced at disulfide C57-C146 being the major inclusion protein, constituting at least 50% of the protein content. Ten co-aggregating proteins were isolated, some of which were already known to be present in cellular inclusions. Of great interest was the presence of several proteins that normally reside in the endoplasmic reticulum (ER), which is in accordance with recent data suggesting that the unfolded protein response (UPR) has a role in ALS. To obtain unbiased information on the pathogenesis of mutant SOD1, we performed a total proteome study on spinal cords from ALS transgenic mice. By multivariate analysis of the 1,800 protein spots detected, 420 (23%) were found to significantly contribute to the difference between transgenic and control mice. From 53 proteins finally identified, we found pathways such as mitochondrial function, oxidative stress, and protein degradation to be affected by the disease. We also identified a previously uncharacterized covalent SOD1 dimer. In conclusion, the work described in this thesis suggests that mutant SOD1 affects the function of mitochondria, but not mainly through direct accumulation of SOD1 protein. It also suggests that SOD1 inclusions, present in both the CNS and peripheral tissues, mainly consist of SOD1 but they also trap proteins involved in the UPR. This might be deleterious as motor neurons, unable to renew themselves, are dependent on proper protein folding and degradation.
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| 6. |
- Bergemalm, Daniel, et al.
(författare)
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Superoxide dismutase-1 and other proteins in inclusions from transgenic amyotrophic lateral sclerosis model mice
- 2010
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Ingår i: Journal of Neurochemistry. - : Wiley. - 0022-3042 .- 1471-4159. ; 114:2, s. 408-418
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Tidskriftsartikel (refereegranskat)abstract
- Mutant superoxide dismutase-1 (SOD1) causes amyotrophic lateral sclerosis (ALS) through a cytotoxic mechanism of unknown nature. A hallmark in ALS patients and transgenic mouse models carrying human SOD1 (hSOD1) mutations are hSOD1-immunoreactive inclusions in spinal cord ventral horns. The hSOD1 inclusions may block essential cellular functions or cause toxicity through sequestering of other proteins. Inclusions from four different transgenic mouse models were examined after density gradient ultracentrifugation. The inclusions are complex structures with heterogeneous densities and are disrupted by detergents. The aggregated hSOD1 was mainly composed of subunits that lacked the native stabilizing intra-subunit disulfide bond. A proportion of subunits formed hSOD1 oligomers or was bound to other proteins through disulfide bonds. Dense inclusions could be isolated and the protein composition was analyzed using proteomic techniques. Mutant hSOD1 accounted for half of the protein. Ten other proteins were identified. Two were cytoplasmic chaperones, four were cytoskeletal proteins, and 4 were proteins that normally reside in the endoplasmic reticulum (ER). The presence of ER proteins in inclusions containing the primarily cytosolic hSOD1 further supports the notion that ER stress is involved in ALS.
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| 7. |
- Berntsson, Shala Ghaderi, et al.
(författare)
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Analysis of DNA repair gene polymorphisms and survival in low-grade and anaplastic gliomas
- 2011
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Ingår i: Journal of Neuro-Oncology. - : Springer Science and Business Media LLC. - 0167-594X .- 1573-7373. ; 105:3, s. 531-538
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to explore the variation in DNA repair genes in adults with WHO grade II and III gliomas and their relationship to patient survival. We analysed a total of 1,458 tagging single-nucleotide polymorphisms (SNPs) that were selected to cover DNA repair genes, in 81 grade II and grade III gliomas samples, collected in Sweden and Denmark. The statistically significant genetic variants from the first dataset (P < 0.05) were taken forward for confirmation in a second dataset of 72 grade II and III gliomas from northern UK. In this dataset, eight gene variants mapping to five different DNA repair genes (ATM, NEIL1, NEIL2, ERCC6 and RPA4) which were associated with survival. Finally, these eight genetic variants were adjusted for treatment, malignancy grade, patient age and gender, leaving one variant, rs4253079, mapped to ERCC6, with a significant association to survival (OR 0.184, 95% CI 0.054-0.63, P = 0.007). We suggest a possible novel association between rs4253079 and survival in this group of patients with low-grade and anaplastic gliomas that needs confirmation in larger datasets.
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| 8. |
- Brännström, Daniel, 1978-
(författare)
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Reporting Intellectual Capital : Four studies on recognition
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis contributes to the reporting of Intellectual Capital (IC) and includes four papers on the recognition and comparability of IC. IC, often called intangibles in the financial reporting discourse, reflects resources which create value in and for organizations. These resources originate out of human knowledge and capacities, which, through their uniqueness, can provide competitive advantages for an organization. As something intangible, IC is a challenge to report as it is not only a matter of reporting value that has been or can be realized but also a matter of reporting the creative processes focusing on present and future value. This challenge is a particular reflection of how and when to recognize IC as something reportable and is intensified if IC needs to be comparable.The thesis draws on the distinction that is made between mandatory and voluntary reporting when discussing recognition and comparability. Three of the studies relate to firms’ practices of reporting through annual reports. Since these reports contain both mandatory and voluntary sections, reflecting reporting both as a requirement as well as a possibility, different aspects of reported IC is emphasized. Using a wider range of documents, the fourth study relates to the enforcement of the mandatory reporting standards which the firms are required to apply in their reporting.As the overall finding in the thesis, three categories of recognition of IC are developed which reflect differences related to whether the reporting is mandatory, voluntary or, as this thesis argues, something in between. Reflected through the categories, comparability interrelates differently with recognition. The thesis contributes with the description of IC as a foundation for reporting which makes the matter of recognition of IC in reporting complex. It further highlights that through recognition of IC reporting is continuously expanding wherefore it is not possible to identify an end of an already expanded and demarcated reporting regime. In this expansion, by settling what is mandatory reporting through requested characteristics, voluntary reporting is defined.
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